Project Number 05912
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Project Number 05912
R.I.T. 175th Anniversary Motorcycle
Customization and Customization Kit
Documentation
Alexandra Collier – ME
Lee Gagne – ME
Jonathan Howard – ME
John Johnson – IE
Jeremy Rank – IE
Anthony Rounding – IE
Curtis Vana - EE
Rochester Institute of Technology,
Rochester, NY
Faculty Mentor: Dr. James Taylor
Faculty Coordinator: Prof. Paul Stiebitz
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Table Of Contents
TABLE OF CONTENTS ................................................................................................. 2
INTRODUCTION............................................................................................................. 5
HARLEY-DAVIDSON MOTORCYCLES ............................................................................... 5
R.I.T. 175TH ANNIVERSARY ............................................................................................. 5
PROJECT NUMBER 05912 ................................................................................................. 6
CHOPPER RESEARCH ........................................................................................................ 7
NEEDS ASSESSMENT .................................................................................................... 8
DEVELOPMENT OF THE NEEDS ASSESSMENT ................................................................... 8
PROJECT MISSION STATEMENT (QUALITATIVE) ............................................................... 9
NEEDS ASSESSMENT PYRAMID (QUANTITATIVE)........................................................... 14
CONCEPT DEVELOPMENT ....................................................................................... 17
INTRODUCTION .............................................................................................................. 17
GAS TANK ...................................................................................................................... 17
HANDLEBARS/ CONTROLS ............................................................................................. 18
RIDE HEIGHT ................................................................................................................. 18
TIRE ............................................................................................................................... 18
SWING ARM .................................................................................................................... 18
WHEEL DESIGN .............................................................................................................. 19
BRAKES ......................................................................................................................... 19
DRIVE ............................................................................................................................ 19
WHEEL HUBS ................................................................................................................. 19
HEADLIGHT.................................................................................................................... 20
AIR FILTER .................................................................................................................... 20
MODIFY RAKED TREE .................................................................................................... 20
EXHAUST ....................................................................................................................... 21
SEAT .............................................................................................................................. 21
ELECTRICAL ................................................................................................................... 21
CONVERSION KIT ........................................................................................................... 22
CONCEPT DRAWING ....................................................................................................... 22
FEASIBILITY ANALYSIS............................................................................................ 24
INTRODUCTION .............................................................................................................. 24
GAS TANK ..................................................................................................................... 24
HANDLE BARS / CONTROLS ........................................................................................... 25
RIDE HEIGHT ................................................................................................................. 26
TIRE ............................................................................................................................... 26
SWING ARM ................................................................................................................... 28
WHEEL DESIGNS ............................................................................................................ 28
WHEEL HUBS ................................................................................................................. 28
BRAKES ......................................................................................................................... 29
DRIVE ............................................................................................................................ 29
HEADLIGHT.................................................................................................................... 30
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AIR FILTER ..................................................................................................................... 31
MODIFY RAKED TREE .................................................................................................... 31
EXHAUST ....................................................................................................................... 33
SEAT .............................................................................................................................. 33
ELECTRICAL ................................................................................................................... 34
CONVERSION KIT ........................................................................................................... 35
SPECIFICATIONS......................................................................................................... 37
INTRODUCTION .............................................................................................................. 37
DESIGN OBJECTIVES ...................................................................................................... 37
DESIGN SPECIFICATIONS ................................................................................................ 37
Gas Tank ................................................................................................................... 37
Handlebars / Controls............................................................................................... 38
Ride Height ............................................................................................................... 38
Tires and Wheels ....................................................................................................... 38
Swing Arm ................................................................................................................. 38
Wheel design ............................................................................................................. 38
Wheel Hubs ............................................................................................................... 39
Drive ......................................................................................................................... 39
Modify Raked Tree .................................................................................................... 39
Exhaust ...................................................................................................................... 40
Seat ............................................................................................................................ 40
Electrical ................................................................................................................... 40
ANALYSIS AND SYNTHESIS ..................................................................................... 41
INTRODUCTION .............................................................................................................. 41
INCREASED LIGHTING .................................................................................................... 41
HANDLEBAR DESIGN ..................................................................................................... 42
ELECTRONICS................................................................................................................. 44
Specifications of feasible system:.............................................................................. 44
Possible General System Designs:............................................................................ 44
CKP TEST:................................................................................................................ 47
Digital controller Algorithm: .................................................................................... 51
Materials:.................................................................................................................. 52
Digital Controller: .................................................................................................... 53
LED Drivers: ............................................................................................................ 53
Voltage Regulator: .................................................................................................... 55
TRIPLE CLAMP DESIGN .................................................................................................. 56
SWING ARM ................................................................................................................... 61
WHEEL DESIGN .............................................................................................................. 62
WHEEL HUB................................................................................................................... 64
DRIVE ............................................................................................................................ 65
APPENDIX A .................................................................................................................. 67
APPENDIX B .................................................................................................................. 73
APPENDIX C .................................................................................................................. 74
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REFERENCES ................................................................................................................ 77
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Introduction
Harley-Davidson Motorcycles
21-year old William S. Harley and 20-year old Arthur Davidson produced their first
motorcycle in 1903. The bike was built in a 10 x 15 foot wooden shed with the words
“Harley-Davidson Motor Company” crudely written on the door (5). Since 1903, HarleyDavidson has produced the most recognizable motorcycles in the world. Today people
can tour any of the three Harley-Davidson factories and catch a glimpse of some of the
most technologically advanced motorcycle manufacturing process in the world. This
seems a long way from the meager beginnings Harley-Davidson had in a wooden shed
and the company continues to grow. For the past nineteen years Harley-Davidson has
reported record revenues and earnings. During 2004, the motorcycle industry itself
cruised to its 12th straight year of growth. The motorcycle industry is growing so rapidly
that within the past four years 24% more units were sold than in the entire previous
decade (1990-1999) (2). Motorcycling is more mainstream today than ever before and
the numbers prove it. Many motorcycle owners feel no other motorcycle has the look,
sound or feel of a Harley-Davidson.
R.I.T. 175th Anniversary
The Rochester Institute of Technology will be celebrating its 175th anniversary in 2005.
A parade will be held on April 30th of 2005 to honor and celebrate the school’s rich
history. Each of the individual colleges of R.I.T. will be entering a float / presentation
containing a past, present and future theme. The college of engineering wanted to enter a
technical and unique float / presentation that incorporated each of the engineering
disciplines. A proposal to convey the past, present, and future theme of the college of
engineering float / presentation was put together by Dr. James Taylor of the Industrial
and Systems Engineering department. The proposal incorporated the popular phenomena
of motorcycles and the multidisciplinary senior design course. The “past” would be
represented by alumni and friends of alumni riding vintage motorcycles in the parade.
The “present” would be represented by a custom chopper built by engineering students in
senior design. Children of the R.I.T. faculty, staff and community would ride pedal bikes
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in the parade to represent the “future” of the Rochester Institute of Technology. A
multidisciplinary senior design team would be designing and manufacturing a custom
chopper motorcycle for the parade. The faculty of R.I.T. liked the proposal and a
connection between R.I.T. and Santa Cruz Harley-Davidson was revealed. Santa Cruz
Harley-Davidson is one of the largest and most recognized Harley-Davidson dealerships
in the world. The dealership provides bikes, parts, and accessories to Harley-Davidson
enthusiasts. Santa Cruz Harley-Davidson even has a museum displaying vintage
motorcycles, pictures and memorabilia to the people of California and its visitors. The
owner of Santa Cruz Harley-Davidson, Mike James, was kind enough to donate two
brand new 883C Harley-Davidson Sportster Motorcycles to R.I.T. and the senior design
course.
Project Number 05912
Our multidisciplinary senior design team was put together to design and develop a
custom chopper from a stock Harley-Davidson 883C Sportster motorcycle. The Sportster
is Harley-Davidson’s least expensive model. It provides people the opportunity to own a
Harley-Davidson motorcycle for less than seven thousand dollars. Harley-Davidson
makes around five hundred Sportsters each day within their manufacturing facilities and
still has problems keeping up with customer orders. While converting the 883C Sportster
into a custom chopper motorcycle, our senior design team will be simultaneously
developing a custom motorcycle conversion kit. The kit will contain documentation of
the changes made to the stock 883C Sportster Harley-Davidson. Santa Cruz HarleyDavidson could potentially produce, market, and sell these 883C Sportster / Custom
Chopper conversion kits. The conversion kit would provide potential customers the
opportunity to own a low cost custom chopper motorcycle that carries the HarleyDavidson name. There are a number of custom chopper kits on the market right now.
Each of the current kits provides the customer the opportunity to build and develop their
own custom chopper motorcycle. None of the kits are currently produced out of stock
Harley-Davidson motorcycles. This means none of the custom choppers on the market
right now carry the Harley-Davidson name.
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Chopper Research
A chopper motorcycle refers to a radically customized motorcycle. A chopper is created
by removing or “chopping” off unnecessary components from a motorcycle. Items like a
windshield, large fenders, big headlights, crash bars, and big seats are eliminated from
the motorcycles design. Until the late 1960s and early 1970s choppers had made little
impact in the motorcycle world. The release of the legendary movie Easy Rider in 1969
began a whole new motorcycle movement. Motorcycle enthusiast wanted a bike like the
one ridden by Peter Fonda in the movie; they wanted a chopper (7). Backyard mechanics
and motorcycle designers began to lower the motorcycles suspension and replace the
standard big front wheel, head light and fuel tank with smaller ones. As the front tire
became smaller the rear tire became larger and larger. Bikers started raking the front end
of their choppers so the angle of the fork to the ground began to decrease. The
handlebars on choppers are often raised higher than standard handlebars and are referred
to as ape hangers. The chopper style made for a bike that was unique and tailored to the
individual rider. It is important to remember that each individual motorcycle rider or
designer decided what needed to be changed to his or her motorcycle to create a custom
chopper.
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Needs Assessment
Development of the Needs Assessment
On December 3rd our senior design team was introduced to one another. The team was
introduced to the project and the group members were instructed to begin researching
chopper motorcycles. Our team researched magazines, websites, and even television
programs involving motorcycle customization and modification. The team gathered
ideas of what modifications needed to be made to a standard 883C Sportster HarleyDavidson to create a “custom chopper look”. The team developed a preliminary list of
order qualifiers that created an excellent starting point for our first conversation with
Mike James, the owner of Santa Cruz Harley-Davidson.

The team comprised a list of order qualifiers and proposed the changes to Mike
James during a teleconference on December 10th, 2004. The “top level” list of
potential modification ideas was comprised from research done by the team and
the teams’ previous knowledge of motorcycles.
o Front end of the bike shall change
o Rear end of the bike shall change
o Sheet metal of the bike shall change
o Seat of the bike shall change
o Paint on the bike shall change
o Electronics on the bike shall change
o Ride height of the bike shall change
o Custom conversion kit shall be “bolt on”
The senior design team was able to convey our understanding of the changes that needed
to be made to a stock 883C Sportster Harley-Davidson to Mike James and his custom
designer Bob Davis. During the teleconference the team received great feedback that
aided in the development of the team’s needs assessment. Mike James and Bob Davis of
Santa Cruz Harley-Davidson seemed very excited about the project. They understood
and recognized that nothing like this project (a low cost custom chopper that carries the
Harley-Davidson name) was on the market right now. Our senior design team was able
to develop a complete list of order qualifiers after the teleconference with Santa Cruz
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Harley-Davidson. Each of the top-level order qualifiers involved a number of steps and
design changes. These numerous changes built deeper and more defined versions of the
initial needs assessment. As one change was made numerous other changes would be
recognized.
Project Mission Statement (Qualitative)
Product
A summary description of what the product is.
(Project)
A multidisciplinary senior design team will be designing and developing
Description
custom choppers from stock Harley-Davidson 883C Sportsters. The
team will simultaneously develop the documentation for a
Sportster/Chopper conversion kit that could potentially be marketed and
sold by Harley-Davidson or motorcycle parts distributors.
Scope
A description of what features the product shall contain and/or what
Limitations
constraints are placed on the project.

Santa Cruz Harley-Davidson has donated two Harley-Davidson
883C Sportsters.

Funds to design and develop the conversion from a stock
Sportster to a custom chopper should not exceed nine thousand
dollars per bike.

Sheet metal on bikes shall change

Wheels on bikes shall change

Seats on bikes shall change

Front end on each bike shall change

Rear end of each bike shall change

Swing arm on each bike shall change

Electronics on each bike shall change

Paint on each bike shall change

At least one bike (Tiger 175th Chopper) shall be finished and
operable on April 30th for the Rochester Institute of Technology
175th anniversary parade.

Kit documentation completed by end of Senior Design Two.
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Stakeholders
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A list of all groups that will in some way interact with the product.

Multidisciplinary senior design team

Dr. James Taylor – Faculty Sponsor / Project Leader

Rochester Institute of Technology


-
College of Engineering Parade Display
-
Permanent Engineering Building Display
Santa Cruz Harley-Davidson
-
Mike James (President)
-
Bob Davis (Custom Department)
Auction participants (in order to generate funds by selling one of
the custom Sportsters)
Key Business A discussion of financial measures of success, such as profit, return on
Goals (CFPs)
investment, payback period, net present value, etc. These are big picture
statements that address why there is a project in the first place.

Provide a low cost custom chopper that will carry the HarleyDavidson name. There are a number of chopper kits that exist
within the market right now. When the kits are put together and
the finished bike is assembled it does not carry the HarleyDavidson name. By providing a kit to convert a Harley-Davidson
into a chopper, the Harley Davidson name is carried over to the
custom chopper.

Provide the everyday Harley-Davidson owner with the
opportunity to obtain a custom chopper.

Provide a custom chopper in the ten to fifteen thousand dollar
range; this goal would make our proposed chopper conversion
cheaper than the current low end kit bike that does not carry the
HD name.

Provide a “bolt on” kit that could be assembled by the average
mechanic.
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Financial
Detailed financial analysis that itemizes development costs,
Analysis
manufacturing costs, sales volume, cash flow, etc. This will be a more
detailed analysis that can help guide the design and be a vehicle for
comparison among alternatives.
The cost constraints listed hear do not pertain to the actual custom
chopper prototype bikes that our team will be producing. The costs listed
pertain to the kit documentation that will be put together for the end of
Senior Design Two. The senior design team will be producing high end
and high cost prototypes of the finished kit product.
Tiger Copper Preliminary Budget- Per Bike Costs




Sheet Metal
-
Gas Tank ($400)
-
Gas Cap ($100)
-
Petcock ($80)
-
Chin Fairing ($110)
-
Front Fender ($200)
-
Rear Fender ($260)
Wheels/Tires
-
Wheel Blanks - front and back ($400)
-
Valve Stems ($12)
-
Front Tire ($135)
-
Rear Tire ($230)
Front End
-
Fork Tubes ($280)
-
Springs ($100)
Controls
-
Handlebars ($100)
-
Risers ($200)
-
Mirrors ($100)
-
Grips ($230)
-
Headlight ($100)
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
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Misc.
-
Paint ($1000)
-
Seat ($500)
-
Exhaust ($500)
-
Swing Arm ($1200)
-
Tools ($300)
-
Lift ($595)
-
Leather Jacket ($250)
-
Raw Materials ($1000)
-
Finishing ($500)
-
Parts Production (Brinkman Lab)
-
Marketing Analysis potentially preformed by Santa Cruz
Harley Davidson
Preliminary
A description of the main group of customers. The term ‘customer’ is
Market
loosely defined as those who will be the primary recipient of your work.
In some cases, this may only by your sponsor.
The Harley-Davidson owner who desires a custom motorcycle at a
relatively low cost of ten to fifteen thousand dollars.
Secondary
A description of other customer groups that could be reached with minor
Market
modifications of the product design.
Motorcycle parts distributors could market and sell the 883C Sportster /
Custom conversion kit.
Order
A list of critical performance parameters that make the product (project)
Qualifiers
interesting enough for a customer to consider the product (project) for
purchase (sponsorship). If any of these attributes are missing, then the
product (potential Project deliverables) will not even be considered.

Shall change rear end of bike
o Rear tire shall be between 180 mm and 220 mm
o Shall change swing arm
o Custom rear wheel shall be produced in Brinkman Lab
o Shall modify drive belt cover
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
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Shall change front end of bike
o Rake angle shall change (triple tree)
o Handle bars shall change
o Custom front wheel shall be produced in Brinkman Lab

All sheet metal on bikes shall change
o Fuel tank shall change
o Front and rear fender shall change
o Metal covers shall change

Seat shall change on both bikes

Electronics shall change on both bikes

Paint shall change

Tiger 175th Chopper Bike shall be operable
Order
A list of critical performance parameters that are likely to lead the
Winners
customer to choose your product over that of the competition. These
attributes differentiate your product (project) from the average bear.

Exhaust should change
o Possibly exit exhaust on left side of bike

Cases should be modified

Should change drive system to a chain from the existing belt

Custom calipers and/or rotors should be implemented

Should upgrade control cables

Should modify controls
o Grips
o Pegs
Innovation

Should upgrade existing gages

An LED brake light should be implemented

Should change signal lights

Should change existing mirrors
Features, performance levels, and technologies in the vase product
Opportunities design that could be significantly improved in an effort to product
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significantly greater sales (or utilization of the project deliverables).
Other

All parts in the kit could actually be produced

Nitrous could be added to the bike

Wheelie bar could be added

Could add a 340 mm rear tire

Could upgrade engine

Increase the rakes to an extreme amount
Other relevant information that impacts the project. Feel free to add new
categories.
Bike must be aesthetically pleasing.
Needs Assessment Pyramid (Quantitative)
A multidisciplinary senior design team will be designing and developing custom
choppers from stock Harley-Davidson 883C Sportsters. The team will simultaneously
develop the documentation of a Sportster / Chopper conversion kit that could potentially
be marketed and sold by Harley-Davidson or motorcycle parts distributors.
Level (1) – Qualifiers

Technological Attributes
o Shall Change Rear End of Bike

Rear tire shall be between 180mm and 220mm.

Custom rear wheel shall be machined from a blank in the Brinkman
Lab


Purchase or fabricate hub.
Modify the swing arm.

New shocks shall be implemented

The drive train will need to be modified so that the secondary
drive is in line.
o The right side transmission cover (case) will need to be
modified or redesigned in order to accommodate the
shifting of the front pulley or sprocket.
Project Number 05912

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Modify brake caliper position to line up with rotor.
o Shall Change Front End of Bike

Rake angle shall change via the triple tree (modify triple tree
geometry).


Fork length will be modified to match the change in rake angle.
Custom front wheel shall be machined from a blank in the Brinkman
Lab.

Purchase or fabricate hub.

Custom handlebars shall be fabricated and/or purchased.

Modify brake caliper position to line up with rotor.
o All sheet metal on the bike shall change

Custom fuel tank shall be purchased and possibly modified.

Custom fenders shall be purchased and possibly modified.
o Custom seat shall be purchased to fit 883C Sportster; if custom seat does not
fit to seat pan a new seat pan will need to be fabricated.
o Electronics shall change

Variable Intensity Light added to bike

o
Paint shall change


Adding hidden lights / similar to neon under glow kit
Change paint on all sheet metal of each bike
Performance Attributes
o At least one bike (Tiger 175th Chopper) shall be finished and fully operable on
April 30th for the Rochester Institute of Technology 175th anniversary parade.

The 175th Chopper shall be operable with all order qualifiers and
technical attributes implemented.
o The second bike (Tiger 175th Chopper replica) shall be finished and fully
operable by the end of Senior Design Two.

The 175th Chopper shall be operable with all order qualifiers technical
attributes implemented.

Schedule Attributes
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o At least one bike (Tiger 175th Chopper) shall be finished and fully operable on
April 30th for the Rochester Institute of Technology 175th anniversary parade.
o The second bike (Tiger 175th Chopper replica) shall be finished and fully
operable by the end of Senior Design Two.

Economic Attributes
o Provide the everyday Harley owner with the opportunity to obtain a custom
chopper.
o Provide a custom chopper in the ten to fifteen thousand dollar range; this goal
would make our proposed chopper conversion cheaper than the current lowend kit bike that does not carry the HD name.
o Funds used to design and develop the conversion from a stock 883C Sportster
to a custom chopper should not exceed nine thousand dollars per bike.
Level (2) – Winners

Technological Attributes
o Exhaust should change

Exit exhaust on left side of bike
o Cases should be modified

Customize (anodize, engrave)
o Should change drive system to a chain from the existing belt
o Custom calipers and/or rotors should be implemented
o Should upgrade control cables
o Should modify controls

Grips

Pegs
o Should upgrade existing gages
o An LED brake light should be implemented
o Should change signal lights

Should change existing mirrors
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Concept Development
Introduction
After the completion of the Needs Assessment, the team began to work on the Concept
Development. The Needs Assessment was used as a reference for any and all areas of
change. The team brainstormed and obtained different ideas on how to change parts of
the bike to achieve the goals that had been set forth in the Needs Assessment. In this
brainstorming session, no idea was too ludicrous; team members reserved all judgment
until the Feasibility Analysis. The teams design ideas were obtained from research,
personal knowledge and conversations with Mike James and Bob Davis of Santa Cruz
Harley-Davidson.
Gas tank

Remove traditional Sportster tank

Replace with radical new tank design
o Custom design

Incorporate RIT Tiger into tank

Make a flowing tank

Make tank with sharp edges to resemble tiger claws
o Custom fabricate

Look to see if metal working students at RIT could do this

Send off to a custom fabricator

Talk to Orange County Choppers to discuss tank ideas
o Custom paint

Hire custom painter

Have powder coated

Have Industrial Designers paint

Replace tank with commercially available tank

Replace tank with commercially available tank with a decorative sheet metal
“skin” on it to achieve custom look
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Handlebars/ Controls

Clean up controls for a sleeker look

Hide controls as much as possible inside of handle bars

Change the shape for a look befitting a chopper not a dirt bike

Use a handlebar or twist grip clutch (as seen on TV, Exile Cycles)

Use a suicide shifter in place of a standard shifter

Create custom foot pedals

Use biomechanics to determine changes
Ride Height

Lower the height of the bike for squatter, more aggressive stance
o Shocks can be shortened to lower bike

Replace shocks to conceal the springs

Change fork length to accommodate the lowering of the bike

Remove shocks and make the bike a rigid

Lowering blocks – spacers that move the rear shock’s lower mount back several
inches, thereby lowering the rear end

Reduce rear suspension travel to compensate for one rider instead of two
Tire

Change the size of the rear tire
o Current width is 150mm
o Possible changes: 180mm, 190mm, 200mm, 210mm, 220mm

Change the front tire to match the rear
o Have a custom made front tire to match the rear
o Buy a tire similar to the rear
Swing arm

Custom build a swing arm to accommodate a wider rear tire

Buy a swing arm to fit around a wider tire
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
Make a single arm swing arm (like Ducati)

Take existing swing arm and clean up welds
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Wheel design

Three “claw” design

Solid wheel design with appearance of spokes

Cut image of a tiger into front and or rear wheel

Manufactured in house (Brinkman Lab)
Brakes

Remove existing calipers

Custom fabricate calipers

Purchase commercially available calipers
Drive

Switch from a belt drive to a chain drive
o If switching to chain, create adaptors to allow for change from belt to
chain

Use a belt not as wide as the existing

Extend the drive out to accommodate an increase in the rear tire width (to keep
the drive in line)

Modify swing arm in order to accommodate a kicked out drive

Remove existing drive covers
o Replace with commercially available chrome covers
o Have existing covers powder coated
o Replace with commercially available colored (black, orange, or other)
cover
Wheel Hubs

Create wheel hubs to accommodate any changes in the drive (belt or chain)
Project Number 05912

Create custom hubs

Purchase existing hubs
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Headlight

Create an original headlight design
o Custom build metalworking
o Custom build/buy glass

Purchase a radical headlight

Go without a headlight

Reuse the stock light
Air Filter

Remove existing

Create a more polished version of existing

Create a new cover design using the existing air filter

Create a new cover using a different type/size/shape of air filter

Display sponsor logos on air filter cover
o Display sponsor logos by engraving onto chrome or other polished metal
o Paint sponsor logos by painting onto air filter cover
o Design cover into shape of a sponsors logo

Go without an air filter cover for a naked look
Modify Raked Tree

Increase rake angle by 5o to 10o (stock is 30.1o)

Design and manufacture new triple trees

Purchase new triple trees

Replace stock triple trees with Mid-glide triple trees

Replace stock triple trees with Wide-glide triple trees

Purchase new, longer front forks
o Purchase chrome forks
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o Purchase black forks
o Purchase orange forks
o Purchase forks to be painted black, orange, or other
o Purchase inverted forks
o Purchase standard forks
Exhaust

Change to a left exiting exhaust

Change exhaust to two into one

Change exhaust to shortened straight pipes

Change exhaust to street sweeper pipes

Custom fabricated pipes
o Fabricate pipes in house
o Purchase custom fabricated pipes

Purchase commercially available pipes
Seat

Remove stock two-up seat

Purchase or fabricate single seat

Purchase or fabricate two-up seat

Purchase or fabricate sissy bar

Dimensions of new seat determined by the tank design

Incorporate logo into the seat
o 175th RIT anniversary
o Sponsor logos
Electrical

Fabricate rear lights into the rear fender (so as the light and housing are flush with
the fender)

Develop proximity sensors to placed on the bike

Develop variable intensity lighting
Project Number 05912

Create accent lighting for engine

Create custom turn signals

Replace keyed ignition with access code ignition

Replace keyed ignition with toggle switch ignition
Page 22 of 77
Conversion Kit

Fabricate each component of the conversion kit and provide the completed kit to
Santa Cruz Harley-Davidson at the conclusion of senior design two. This would
require the team to fabricate or purchase three items of each design component,
one for each of the two motorcycles, and one for the kit.

Provide documentation recommending components that the kit would contain.
Santa Cruz Harley-Davidson would be able to see the prototype kit in action; all
modified design components would be fabricated or purchased and implemented
on the customized motorcycles.

Make the kit “bolt on” so that no welding or cutting was necessary throughout the
customization process.

Provide a kit that accommodates any and all changes that the team desires (this
would include cutting and welding).
Concept Drawing
Based on the concepts developed by the team, the Industrial Designers developed
numerous concept drawings. Figure 1 is an example of one of the concept drawings.
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Figure 1: Concept drawing
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Feasibility Analysis
Introduction
The team performed a feasibility analysis on all of the concept development ideas. This
was done in order to identify the most desirable design option. Pros and cons of each
design were determined and reviewed in making decisions. A number of the design
alternatives were not feasible based on resource and time constraints put on this project;
these design options were not included within the pro and con evaluation.
Weighted
concept analysis and Pugh’s method were utilized in the decision making process for the
design components that proposed a difficult decision. Within these difficult decisions the
best option was not readily identifiable based on the pros and cons.
Gas Tank

Replace with custom designed tank vs. commercially available tanks
o Custom designed tank

Cons:

Team lacks expertise in metalworking (limiting in-house
capabilities)

Cost to outsource fabrication of in-house design: ~$2,000
per tank

Pros:

Radical, one of a kind design

Does not compromise the Industrial Designers’ design
o Commercially available tank


Cons:

Compromises the Industrial Designers’ design

Not a radical design (is not as unique)
Pros:


Cost: ~$600 per tank
Based on weighted concept evaluation, the commercially available tank is the
best option based on the decision criteria. A Pugh’s Method analysis verified
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that purchasing a commercially available tank was the most feasible decision.
The weighted concept evaluation and the Pugh’s method analysis can be found in
Appendix C.
Handle Bars / Controls

Remove current handle bars and controls and replace with custom built handle
bars, built to conceal the bulkiness of the controls vs. purchase commercially
available handle bars that conceal controls
o Custom built handle bars

Cons:

No member of the team has experience designing handle
bars

Pros:

Conceal controls

Changes look of bike from a dirt bike to a chopper
o Purchase handle bars

Cons:


Cost: ~$3000 per set
Pros:

Built by manufactures with experience

Conceal controls

Changes look of the bike from a dirt bike to a chopper
o Suicide shifter


Cons:

Is not most practical deign for everyday riding bike

Is not as safe as standard shifting
Pros:


Radical design giving chopper edge to bike
Purchasing commercially available handlebars is more feasible based on the
teams’ lack of experience with building and designing handlebars. Suicide
shifter is not feasible based on requirement to make the choppers everyday riders.
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Ride Height

Remove shocks to create a rigid vs. shorten shocks to lower ride height
o Remove shocks

Cons:

Turns bike into a rigid, decreasing the ride ability of the
bike

Pros:

Gives bike a sleeker look by removing the shocks
o Shorten shocks

Cons:

May result in possible problems with cornering clearance,
ground clearance and handling


Cost of new shocks $281 per set
Pros:

Gives the bike a squatter stance

As compared to the rigid, the bike is easier to ride
(comfort)

In creating a bike that could possibly be ridden every day, it is more feasible to
shorten the shocks then to make the bike into a rigid.
Tire

Wheel Width
o Width greater then 190mm

Cons:

Rear wheel widths in excess of 190mm will result in a
redesign of the XL (stock) swing arm; may make it
necessary to modify the drive in order to keep it in line.
Time involved to accomplish the redesign/ analysis/
fabrication of the swing arm and drive assembly may be
similar to other entire Senior Design projects.
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
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Pros:

Will give bike the massive back wheel look of a chopper
o Width equal to or less then 190mm

Cons:

Rear wheel may appear to be stock (stock XL width is
150mm)

Pros:

190mm is a proven good look on an XL according to Mike
James of Santa Cruz Harley-Davidson


No swing arm or drive redesign is needed
Based on time constraints and expert opinion, it is more feasible to change the
rear wheel to a width between 150mm and 190mm.

Choosing between the two most commercially available combinations of rear
wheel width and diameter available in the width range of 150mm to 190mm are
190mm width on 17in diameter and 180mm width on 18in.
o 190mm on 17in

Cons:

17 in diameter is smaller then other option with 18in
diameter

Pros:

Width is at apex of what will fit on standard Sportster
frame

Proven good look on Sportster according to Mike James of
Santa Cruz Harley-Davidson
o 180mm on 18in

Cons:


Pros:


180mm is not as wide as other option with 190mm width
Diameter is the larger of the two options available
It is more feasible to use a 190mm tire on the 17-inch wheel because the width of
the tire is more important aesthetically then the wheel diameter. Also, Mike
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James, an expert in the field of Harley-Davidson customization, has
recommended 190mm.
Swing Arm
Based on the analysis of the rear tire width, the 190mm tire will fit inside of the swing
arm. Therefore it is no longer necessary to redesign the swing arm. The single arm
swing arm has been eliminated from consideration based on two facts: it is a concept for
a sport bike, not a chopper; and the design and analysis involved in fabricating a single
arm swing arm are comparable to entire senior design projects in its scope and the
minimum time needed. For these reasons, the existing swing arm will be taken off and
cleaned up aesthetically (slight modifications).
Wheel Designs

Wheels will be designed and fabricated internally, to take advantage of the
Brinkman Lab and the team’s expertise in using the CNC machines. To ensure
the design is sound, structural analysis will be performed.
Wheel hubs

Purchase hubs vs. design and fabricate hubs
o Purchase hubs

Cons:

Forces the team to design the wheel, and drive changes
around the hub


Does not utilize team’s expertise in using CNC machines
Pros:

Hub is professionally designed and fabricated
o Design and fabricate hubs

Cons:


Pros:
Hub is not be professionally designed and fabricated
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
Allows team to design the hub around the other
components of the bike


Utilizes the team’s expertise in using CNC machines
It is more feasible for the team to design the hubs around the other components of
the bike, vs. designing the other components of the bike around the hubs. For this
reason, the team will design and fabricate the hubs in-house.
Brakes

Custom design and fabricate calipers vs. purchasing commercially available
calipers
o Custom calipers

Cons:


Calipers are not professionally designed and fabricated
Pros:

Utilizes team’s skills and resources available

Gives a potential location for incorporating sponsor logos
to bikes

Commercially available

Cons:


Pros:


Does not utilize team’s skills or resources available to team
Calipers are professionally designed and fabricated
Based on the team’s experience with designing and fabricating calipers, it is more
feasible to custom design and fabricate calipers.
Drive

Modify drive to a chain vs. modify drive to a narrower belt
o Chain

Cons:

Forces team to redesign parts of the dive in order to
accommodate change from belt to chain
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
Increased maintenance is required (when compared to a
belt drive)

Pros:

Decreases the amount of space needed for drive as the
chain is narrower then the belt
o Belt


Cons:

Does not open up as much space as the chain belt does

Is not as reliable as wider belt or chain

Would require swing are redesign
Pros:

Does not require as much redesign as the chain drive
does

Based on the Pugh’s Method analysis performed, the chain drive is the most
feasible option. The Pugh’s Method analysis is Figure C-5 located in
Appendix C.
Headlight

Custom fabricate
o It is not feasible to create a custom in-house headlight as the team as no
experience with designing lights or with glass.

No headlight
o It is not feasible to go without a headlight due to safety issues addressed in
the analysis and synthesis section of this paper.

Standard headlight
o It is not feasible to use the standard headlight, as it does not fit the
appearance of the new bike.

Radical headlight
o It is most feasible to purchase a radical headlight based on the elimination
of the previous three ideas. The headlight will be chosen by the Industrial
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Design students in order to have the headlight fit aesthetically with the rest
of the bike.
Air filter

No filter cover
o It is not feasible to go without an air filter cover, as this is a prime location
for sponsor logo placement.

Filter cover
o It is more feasible to remove the cover and replace with a newly designed
cover, than to remove the cover and the filter and start all over. Without
changing the filter type or size, there will not be any concerns over
compatibility.
Modify Raked Tree

Increase rake angle by 5o, 7o, or 10o
o Based on recommendation of Sportster customization expert Bob Davis,
7o was chosen as angle of possible increase


Cons: (of increasing angle)

Potential for stiction

High speed steering reduction due to increased trail
Pros:

Proven good look, good ride by Bob Davis of Santa Cruz
Harley-Davidson

Gives bike chopper look

Part of requirement is to increase rake angle by some
amount

Based on the recommendation of Bob Davis, the team chose 7o as the possible
increase to the rake angle. As increasing the rake angle was a basic requirement
in making the Sportster into a chopper, 7o is the most feasible increase to the rake
angle.

Purchase new triple trees vs. fabricating new triple trees
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o Purchase new triple trees

Cons:

Purchased triple trees cost ~ $225

Does not utilize team’s expertise in using CNC machines in
the Brinkman Lab

Pros:

Professionally manufactured
o Design and fabricate custom triple trees

Cons:


Team has no experience with designing triple trees
Pros:

Will utilize teams expertise in using CNC machines in the
Brinkman Lab

Team has experience designing and fabricating similar
parts


Only cost incurred is for blanks
Based on the team’s expertise in using the CNC machines in the Brinkman Lab,
and the cost savings in purchasing blanks over finished products, it is more
feasible to design and fabricate custom triple trees in house.

Mid-glide front-end vs. Wide-glide front-end
o Both front-end arrangements give the bike a wider stance from the front.
However, the Wide-glide might appear too wide on the smaller Sportster.
It for this reason the Mid-glide front-end is more feasible then the Wideglide.

Based on the requirement to increase the fork angle, new longer forks will need to
be purchased to accommodate this change.

The decision to choose inverted forks vs. standard forks, and the color of those
forks has nothing to do with performance and everything to do with style and
looks. For this reason, the Industrial Design students have been tasked with
choosing the fork style and color. They have decided inverted forks will be
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purchased for the bike; one bike will have chrome forks while the other will have
black.
Exhaust

Remove current exhaust and replace with custom pipes on right hand side vs.
custom pipes on left hand side
o Right hand exhaust

Cons:

Looks like the majority of bikes on the market (both stock
and custom) as right hand exhaust is standard

Pros:

Sportster 883C is built with and for right hand exhaust

Proper flow of exhaust can easily be maintained

o Left hand exhaust

Cons:

Proper flow of exhaust may be difficult to obtain on
Sportster

Sportster 883C is not built for left hand exhaust, leading to
possible issues with space constraints

Pros:

Left hand exhaust is not the norm, thereby helping to create
a custom look


Will give the exhaust a radical look
Based on the difficulty with redesigning the exhaust pipes to accommodate a left
side exhaust, it is more feasible to make the exhaust on the right side of the bike.
Seat

New two up seat
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o It is not feasible to use a two up seat because the new fiberglass fender
will not be able to support a weight of a rider the way the current sheet
metal fender does.

Sissy bars
o Although sissy bars are common on choppers, they do not fit aesthetically
with the design concept for the bike.

Single seat
o Based on the elimination of the two up seat, the single seat is the most
feasible. The single rider seat will be purchased and then modified to both
fit the bike and to showcase sponsor logos.
Electrical
With the Sportster 883C’s participation in a parade, efforts were made on the
electrical system aspect of the bike to make it stand out. Special lighting effects were the
first to be considered in order to receive high visibility when the bike is in motion.
Another key issue addressed was the safety of the rider. As mentioned, many traffic
fatalities involving motorcycles are due to the low visibility of motorcyclists. So keeping
safety and visibility in mind, several concept systems were developed. Two systems
stood out as feasible, and were researched for the duration of the quarter.
The first concept system was a safety feature for the stock 883C Sportster which
would implement LED and RF technology. Using motion/proximity sensor technology, a
proximity sensor system will ensure that all automobiles within a determined perimeter
around the bike are alerted to the bike’s presence. The bike would be fitted with LEDs
that would illuminate when an automobile is detected by the onboard sensors. The
sensors would communicate with a main control unit, which would illuminate the LED’s
via a LED driver. A search for appropriate proximity sensors yielded three distinct types:
Infrared, Capacitive, and Inductive. Searching for sensors of the capacitive and inductive
type yielded disappointing results. The maximum range of theses types of sensors was
on the order of millimeters, an unacceptable range. A new search pertaining to infrared
sensors found a larger sensing range, but required a clean surface for reflection. The
remaining option in implementing this system was to purchase an existing system that
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utilized sensors with adequate range. This led to the discovery of RSE Developments
Parktronic Radar system. This system is a product of RSE Developments and is used in
Mercedes-Benz automobiles. The system detects objects to the rear of a vehicle up to a
meter away. This system would be costly and would need to be modified to fit the
motorcycle. Modification of the system would be difficult without manufacturer
information, and could possibly violate proprietary rights. Seeking advice from
professors in the RF field, the collective agreement was that the system would take some
time to implement. Given a deadline of April 30th, a set budget, and limited human
resources, the system was determined to be not feasible.
The second concept system also embodies the two goals of safety and high
visibility. The Accent Lighting System was envisioned to provide an artistic lighting
appeal while alerting nearby motorists to the bike’s presence. This lighting system would
flash or grow in intensity based on the RPM of the motorcycle motor. The system would
be powered by the bike’s 12V battery. The system would have to be power efficient, thus
LEDs were determined to be the source of lighting.
Conversion Kit

Fabricate each part three time vs. develop documentation to support custom
customization
o Fabricate each part three times

Cons:

Producing each part three times increases the cost of the
project by approximately 30%

Parts to be used on Tiger Chopper are extremely custom
and specific to this bike/project

Two models (Tiger Chopper and Tiger Chopper replica)
will already exist

Pros:

Santa Cruz Harley-Davidson will have physical
representation of what kit would contain
o Develop documentation
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
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Cons:

Santa Cruz Harley-Davidson will not have a physical
representation of what kit would contain

Pros:

Cost effective: team will not waste limited budget on parts
not needed to complete the two bikes

Will be more flexible: team can suggest items similar to
what was used in projects bikes, that may not be exactly the
same
o The Tiger Chopper will be highly customized to
meet the needs of RIT, Kate Gleason College of
Engineering and our team’s requirements for Senior
Design. These needs most likely are not the same
for the potential consumer of the conversion kit.

Resource effective: team will not waste valuable time and
machine time by producing a third set of parts

Based on the team’s budget, constraints on time and machining resources, it is
more feasible to develop documentation for the conversion kit then it is to
produce three sets of parts.
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Specifications
Introduction
This section outlines the design objectives and determines the performance and design
specifications the project must meet.
Design Objectives
The overall goals of the final project design make up the design objectives.

Convert a stock 883C Harley-Davidson Sportster motorcycle into a custom
chopper motorcycle. This conversion must be completed without modifying the
frame. The conversion component parts must be manufactured so that a typical
motorcycle mechanic could assemble the custom motorcycle.

Documentation of all the customization changes must be accounted for and
compiled. This documentation will represent a customization kit that could be
assembled, marketed and sold by Harley-Davidson, or motorcycle parts
distributors.

The custom designed motorcycle that the senior design team creates must be
operable.
Design Specifications
Design specifications dictate the functionality of the final design. The specifications
were determined from the feasibility analysis.
Gas Tank

Replace stock gas tank with a smaller more astatically pleasing commercially
available gas tank. The commercially available tank will be selected to match the
design drawings of the finished motorcycles gas tank provided by our teams’
industrial designers.
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Handlebars / Controls

Replace existing handlebars / controls with a more astatically pleasing
commercially available set of handlebars / controls. The commercially available
handlebars / controls will be selected to match the design drawings provided by
our teams industrial designers.
Ride Height

Replace existing rear shocks (12 inch eye to eye), with a commercially available
(11 inch eye to eye) astatically pleasing set of rear shocks. This change aids in
lowering ride height of the finished motorcycle approximately one inch.
Tires and Wheels

The team will replace the stock 150 mm rear tire with a commercially available
190 mm rear tire.

The team will replace the stock 90 mm front tire with a more astatically pleasing
commercially available 90 mm front tire that matches the rear tire design.

The team will purchase a commercially available rear wheel blank that will fit the
190 mm rear tire. The team decided to order a 17-inch diameter, 190 mm rear
wheel blank.

The team will purchase a commercially available front wheel blank (21-inch
diameter, 90 mm).
Swing Arm

The team will remove and slightly modify the existing stock swing arm on each
motorcycle. The swing arm from each motorcycle will be cleaned up (weld
marks minimized) and repainted to match the frame design.
Wheel design

Wheels will be designed and fabricated internally, to take advantage of the
Brinkman Lab and the teams expertise in using the CNC machines. The design of
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the front and rear wheel is displayed in the analysis and synthesis section of this
paper. To ensure the design is sound, structural analysis will be performed.
Wheel Hubs

The team will design and fabricate the wheel hubs to fit the wheel designs. The
team will purchase stock aluminum and machine the designed hubs in the
Brinkman Lab.
Drive

Team decided to replace the existing Kevlar belt drive with a chain drive. The
team will calculate a new drive ratio in implementing the chain drive.
Headlight

Replace existing headlight with a more astatically pleasing commercially
available headlight. The commercially available headlight will be selected to
match the design drawings provided by our teams’ industrial designers.
Air Filter

The team will design and fabricate a custom air filter cover to replace the stock
cover. The custom air filter cover will be machined in the Brinkman Lab to
match the design drawings of the industrial designers.
Modify Raked Tree

Team chose to increase the rake angle by seven degrees. This would be
accomplished in the design and fabrication of the triple clamps.

The stock front forks are going to be replaced with an alternate set of
commercially available front forks. The commercially available front forks that
are going to be purchased will match the design objectives set forth by the
industrial designers. The new front forks need to be longer than the stock front
forks to compensate for the increased rake angel. These calculations are
displayed within the analysis and synthesis portion of this paper.
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Exhaust

The stock exhaust pipes will be replaced with custom designed exhaust pipes that
represent the design set in place by the industrial designers.
Seat

The stock two up seat will be replaced with an alternate commercially available
single seat.

The senior design team will create a single seat pan in order to implement a single
seat design. The single seat pan will be a modified version of a commercially
available seat pan.
Electrical

The senior design team will concentrate our efforts in the electrical department to
the development of a LED lighting system. This system will be variable based on
the RPM of the bike, thereby giving the motorcyclist more visibility at higher
(more dangerous) speeds. This lighting will also be used to accent the engine.
Conversion Kit

Each portion of the motorcycle customization will be documented. This
documentation will make up a paper version of the customization kit.
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Analysis and synthesis
Introduction
This section reviews the analysis used to determine the specifications of the project.
Increased Lighting
Approximately 4.9 million motorcycles were registered in the United States in
2001. While these represent only 2% of all registered vehicles, motorcycles account for
7% to 12% of all motor vehicle-related fatalities. Per mile traveled, motorcyclists are 16
times more likely than passenger car occupants to die in a traffic crash and four times as
likely to be injured. While only 20% of car crashes result in injury or death, that number
increases to 80% for motorcycle crashes.
A study put together by Harry Hurt of the University of Southern California
investigated the causes and effects of motorcycle accidents. Hurt investigated almost
every aspect of 900 motorcycle accidents in the Los Angeles area. Additionally, Hurt
and his staff analyzed 3,600 motorcycle traffic accident reports in the same geographic
area. Hurt and his staff were able to identify a number of interesting findings that aided
in our teams motorcycle design.
Hurt found that approximately three-fourths of the motorcycle accidents he
studied involved collision with another vehicle, which was most usually a passenger
automobile. During two-thirds of these accidents (involving collision with another
vehicle) the driver of the other vehicle violated the motorcycle right-of-way and caused
the accident. The failure of motorists to detect and recognize motorcycles in traffic was
the predominating cause of motorcycle accidents. The driver of the other vehicle
involved in the collision with the motorcycle did not see the motorcycle before the
collision, or did not see the motorcycle until too late to avoid the collision.
After reading Harry Hurt’s reports on motorcycle accidents, our senior design
team realized that efforts needed to be taken in order to improve motorcycle conspicuity.
The team proposed the implementation of a LED lighting system. The LED lights would
add to visual detection of the motorcycle. A study published in the Journal of Safety
Research, by Freedman and Davit reported on the aspects of adding lights to the sides
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and rear of motorcycles and mopeds. The study found that the adding lights to the
motorcycles rear and sides improved conspicuity. Adding the lights and improving the
conspicuity of motorcycles and mopeds would hopefully reduce the number of
motorcycle accidents caused by failure to detect a motorcycle in traffic.
Handlebar Design
Based on studies of motorcycle use, one of the primary complaints of riders is
muscle fatigue in the upper arm and shoulder. One of the goals of this project was to
provide the end user with a chopper style motorcycle that is capable of being an
“everyday rider.” Therefore, biomechanics were utilized in the design of the handlebars
for the motorcycles in order to reduce the moment at the shoulder.
The ideal handlebar design would consist of the smallest moment at the shoulder
while maintaining full functionality. The smallest moment at the shoulder would consist
of the arm positioned straight down. However this position is not functional to control
the motorcycle. On the other extreme, the moment would be the largest with the upper
arm and forearm fully extended in front of the rider. Therefore the optimal design was
somewhere in between these positions. The project team experimented with various arm
angles to determine the smallest moment while still maintaining full arm motion required
to use the handlebars safely. This position was found to be 45 degree angle at the
shoulder-upper arm, and the forearm be fully extended (Figure 2).
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45 degrees
Figure 2: Optimal arm position during riding
After the arm position was developed, the physical measurements of the end users
needed to be calculated. The ANSUR military database was used to determine the
forearm, upper arm, and sitting torso lengths for the end user. No user data was available
for the H-D Sportster 883C, however it has been given a reputation as a motorcycle for
both genders. Harley Davidson produces a Sportster 883L which is smaller and more
applicable for smaller females. A range was used to determine the physical
measurements of the Sportster 883C end user. The smallest rider was determined to be
the 40th percentile female based on leg length and ride height constraints. The largest
rider was calculated to be 70th percentile male based on leg length and the distance
between the seat and foot controls. The range provided a rough estimate of the end users
assuming smaller females would use the 883L, and larger males would use a larger style
motorcycle. Based on these measurements and the optimal arm position, it was
determine that the handlebars needed have a 27 inch horizontal distance from the back of
the seat to accommodate the 40th percentile female. (See appendix for calculations).
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This measurement allows for the reduction of the shoulder moment for the average end
user.
Electronics
Specifications of feasible system:
The accent lighting (LEDs) will illuminate the bike’s motor components. The LEDs will
blink at four discrete frequencies throughout the 5600RPM spectrum. The rider will have
control over the LEDs through an on/off switch, and a selector that will allow him to
choose two different modes of operation.
In the first mode, the LEDs will appear to be constantly on. The second mode of
operation will result in the LEDs blinking at a frequency proportional to the RPM of the
motor. An outline of the blink frequencies is shown in Table1.
RPM
Blink Frequency
0-1500
Constant On Note: The bike is in Neutral/Park/Motor Off
1500-2000 10Hz
2000-3000 20Hz
3000-4000 30Hz
4000-5600 40Hz
Table1: Blink Frequency Table.
The control of the modes of operation will be a responsibility of the control unit. This
control unit will be powered by the motorcycle’s 12V battery and will be an analog
circuit, or a digital controller.
Possible General System Designs:
The initial system design yielded two possible options in powering the LEDs with the
implementation of a digital controller. The third design shows the controller being an
analog circuit. The LEDs will be powered by an LED driver that is connected to the
battery as shown in Figure 3. This LED driver will be controlled by the digital controller.
This system is attractive due to multiple ways of implementing the LED driver.
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User Interface
RPM signal
Digital
Control
Unit
12VDC
Battery
LED Driver
Accent Lighting( LEDs)
Figure 3: Digital Controller- Relay driven system
The second design would eliminate the LED driver, and allow the digital controller to
drive the LEDs directly. This system is shown in Figure 4. This system was found to be
impractical due to the operating output voltage of researched digital controllers being less
than 12V.
User Interface
RPM Signal
Digital
Controller
12VDC
Battery
Accent Lighting (LEDs)
Figure 4: Digital Controller powering LEDs directly
The third system design shows the LEDs being powered by an analog circuit that will
read the RPM signal and condition it to provide ~12V to the accent lighting. This system
is outlined in Figure 5.
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User Interface
RPM Signal
Analog
Circuit
12VDC
Battery
Accent Lighting
Figure 5: Analog control circuit conditioning RPM signal and powering LEDs
The LEDs were chosen by the industrial designers in order to be coherent with their
vision of the bike. These lights were purchased from Kuryakyn. The LEDs were tested
and were found to handle 14V and drew .41A safely. This voltage is well above the
battery voltage, which will be powering the LEDs. This test was important to make sure
the lights will handle a voltage that may increase above 12V.
Pugh’s method is shown in Table 2 comparing the three systems.
GENERAL SYSTEM
COMPARISON
Design Complexity
Sufficient Equipment
Cost of Total Materials
Availability of Components
Versatility of Design
Power Efficiency
Mean Score
Normalized Score
Digital Controller-LED Driver Digital Controller Analog Circuit
3
3
2
5
5
5
3
4
2
5
5
5
5
3
1
5
4
3
4.333333333
4
3
1.00
0.92
0.69
Table 2: Pugh’s Method evaluation of possible systems.
Using Pugh’s method, it was determined that the system implemented will be a digital
controller-LED driver pair. This system has an edge over the lone digital controller and
analog controller circuit systems due to its versatility. The digital controller can be
reprogrammed to perform different functions, thus making it very versatile.
Reprogramming a digital controller has a faster turn around rate than redesigning a
hardwired analog circuit. The robustness of this system will make future customization
of the system more time efficient.
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The RPM signal proved to be a difficult part of the design. There were several sources
from which this signal could be read by the digital controller. The sources that provided
an alternating signal or voltage that varied proportionally to increasing RPM are the
alternator, voltage regulator, ignition control module, and crank position sensor (CKP).
The initial design would read the voltage changes coming from the voltage regulator.
The downside of this would be the need for additional circuitry to limit the amount of
voltage the digital controller experiences. This regulated voltage would not have a
frequency associated with it, thus a variation in RPM would not be detected. The next
source considered was the tachometer DATALINK signal. The waveform of this signal
was not mentioned in the service manuals, so the best estimation was that it being a
square wave that varied in duty cycle or frequency. Initial tests with the oscilloscope
connected to the line yielded a signal that peaked at ~8V. The origin of the signal was
traced to the Ignition Control Module (ICM). The ICM received and processed the signal
from the crank position sensor. Contact was made with technical support at HarleyDavidson, which resulted in learning that the information on the DATALINK signal was
proprietary. The final decision was to use the signal that comes directly out of the crank
position sensor. This signal is not modified by any hardware and process that is deemed
proprietary. The next process was to choose a sufficient digital controller that could
sample such a signal that varied in frequency.
CKP TEST:
The crank position sensor on the Sportster was tapped and the signal measured. This
signal is assumed to alternate in frequency directly with motor rotation. The voltage
level of this signal was a major concern due to the sensitivity of the digital controller and
its voltage limits. The signal was measured to be ~27V at idle which is about 1000RPM
(+/- 50). The bike was then revved to approximately 75% of redline (5600 RPM). This is
an approximation due to the lack of a tachometer on the bike. The voltage level of the
signal at 75% was found to be ~45V (4200RPM). Due to the lack of information on the
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hardware and its specifications (proprietary information of Harley-Davidson Motor
Company), a linear approximation of voltage levels was made as a function of RPM.
RPM
1000
2066
3126
4186
5252
Voltage of Signal
27V
33V
39V
45V
51V
Table 3: Approximate voltage level of RPM signal
After performing the CKP test, a new addition to the general system design was realized.
The problem with the CKP signal is that the voltage level fluctuates from 27V at idle to
over 45V near redline. The majority of digital controllers can only read signals less than
5V. A circuit will have to be designed to limit the voltage that the digital controller is
exposed to, thus the design in Figure 6. A simple voltage divider will be able to divide
the incoming voltage level of the signal. The calculations for the resistor values of the
voltage divider are shown in Calculations 1.
Calculations 1:
The RPM signal voltage is reduced to 6.25% of it original value through voltage division.
2.2k
k
 .0625
2.2k  33k
After the signal is voltage divided, it has to be read by the digital controller at less than
5V. The answer to further regulating the voltage was to implement a MOSFET transistor
at the output of the voltage divider.
This MOSFET will constantly operate in the
saturation region with each positive going transition being conveyed to the digital
controller. By counting the number of positive transitions that occur in a second, a
frequency is calculated by the digital controller. This frequency would then be modified
by a scalar. This scalar would determine the frequency at which the LEDs blink. A
MOSFET does not conduct current through the gate terminal, and theoretically has an
infinite resistance between drain and source terminals. These characteristics allow the
voltage division stage to operate ideally. These characteristics also allow the MOSFET
to isolate the voltage divider and any harmful current spikes. The two series resistors
attached to the source terminal of the MOSFET will drop the voltage of the input to the
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digital controller. The first resistor determines the upper voltage limit that the digital
controller will sample. The second resistor will determine the lower limit of the input
and prevent a shorting of the signal to ground.
A maximum of 3.08V will be generated as digital controller input when the bike reaches
the approximated RPM redline. A voltage level of 1.308V will be sent to the digital
controller when the motor is at idle. The general design is shown in Figure 6. The
voltages at key RPM values were estimated from the CKP test (Table 3).
It was
determined from iterative PSPICE simulations that for the MOSFET to receive gate
voltages within its scope, the RPM signal voltages will be reduced to 6.25% of their
value. The circuit was simulated in PSPICE to ensure proper operation of the regulator
within the voltage range of the signal from idle (1000RPM) to redline (5600RPM). The
results of this simulation are shown in Figure 7 and Figure 8.
From CKP
V1
R4
M1
0
0
33k
FREQ = 16hz
VAMPL = 27V
VOFF = 0v
MbreakN
V
R5
12k
R6V
2k
0
V
R3
8.2k
0
Figure 6: Voltage regulator circuit
To Digital Controller
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6.0V
(77.185m,5.7241)
5.0V
4.0V
Input voltage level at 27V (Idle)
3.0V
(77.185m,1.6735)
(16.560m,1.3455)
2.0V
1.0V
0V
-1.0V
0s
V(R6:1)
10ms
V(M1:d)
20ms
V(R6:2)
30ms
40ms
50ms
60ms
70ms
80ms
90ms
100ms
Time
Figure 7: PSPICE simulation results of voltage regulator at IDLE RPM
15V
(34.783m,10.116)
Input voltage at approximated redline(5600RPM)
10V
(24.144m,3.9187)
5V
3.0320m,3.0821)
0V
-5V
0s
V(R6:1)
10ms
V(M1:d)
20ms
V(R6:2)
30ms
40ms
50ms
60ms
70ms
80ms
90ms
100ms
Time
Figure 8: PSPICE simulation results of voltage regulator at estimated redline RPM
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Digital controller Algorithm:
The algorithm to control the overall lighting process will involve acquisition of the RPM
signal, processing of that signal, and relaying the signal to the LED driver. The algorithm
will also iteratively check the state of the on/off switch and the mode selection switch.
The digital controller algorithm will be programmed in C language and compiled into
assembly language. The flow chart of the algorithm is shown in Figure 9.
Check Status of Mode
Switch
Mode1:
Sample RPM
frequency
Mode1?
LEDs
Constant On
If RPM
<2000
If RPM
<3000
LEDs Flash
at 10Hz
If RPM
<4000
LEDs Flash
at 20Hz
If RPM
<5000
LEDs Flash
at 30Hz
Else
LEDs Flash
at 40Hz
Figure 9: Flowchart of digital controller algorithm
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Pseudo code for the algorithm is shown in Figure 10.
//Accent Lighting System control
//Interrupts:
Check state of mode selection switch
IF status = modeOne
//Processing of RPM signal:
For Loop (Read signal for 1 second) // Count number of on’s that occur in a second
if( input > Threshold of positive transition )
counter++;
// Count the number of positive transitions
end
counter = freq;
// Divide counter to output corresponding frequency in accordance with frequency
table
If( counter < 2000 RPM)
Output lights constant on.
If( counter < 3000 RPM)
Output to lights at frequency 10Hz
//Divide the RPM signal frequency so LED blinking is visible
output = freq* ProportionalConstant;
If( counter < 4000 RPM)
Output to lights at frequency 20Hz
output = freq* ProportionalConstant;
If( counter < 5000 RPM)
Output to lights at frequency 30Hz
output = freq* ProportionalConstant;
Else
Output to lights at frequency 40Hz
output = freq* ProportionalConstant;
ELSE
Send to LED controller 5V Constant on mode
Figure 10: Pseudo code for digital controller
Materials:
User Interface:
Keeping a budget in mind, the interface to control the lighting was kept simple to C&K
TP Series Tiny Pushbutton Switches. The alternative to push button switches was an
LCD touch screen interface. This could not be implemented in the time scale of this
project due the amount of electronics experience on the team.
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USER INTERFACE COMPARISON Pushbutton Switches
LCD Touch Screen
Design Complexity(Implementation
3
2
Sufficient Equipment
3
3
Cost of Total Materials
4
1
Availability of Components
4
3
Versatility of Design
3
5
Power Efficiency
3
1
Mean Score
3.333333333
2.5
Normalized Score
1.00
0.75
Table 4: Pugh’s Method evaluation of user interfaces
Digital Controller:
The digital control unit sought after must allow for input/output ports for the user
interface mode selection, on/off switch, RPM signal, and output to drive the LED driver.
Research of an appropriate controller led to the following comparison shown in Table 5.
The controllers considered were:
DIGITAL CONTROLLER
COMPARISON
Manufacturer
Memory Size (FLASH)
RAM
EEPROM
NVDS
VDD
Operating Voltage
I/O Lines
UART
Serial Lines
A/D
CLK Speed
Power Dissipation
Price
PIC-12F629
Microchip
1024Kx14 words FLASH
64bytes
128bytes
Z8F011AHH020EC
Zilog
1K
256bytes
CY8C22113-24PI
Cypress
2K
256bytes
16bytes
6.5V
2V - 5.5V
6
yes
4
20MHz
800mW
1.68
2.7-3.6
17
1
no
3
20MHz
24MHz
3.18
2.50
6
Table 5: Comparison of digital controllers.
This circuit will have a high degree of flexibility with the implementation of a microcontroller as compared to an analog circuit. The frequencies at which the LEDs blink can
be changed with modification to the controller’s code.
LED Drivers:
The search for an appropriate LED driver resulted in the following devices shown in
Table 6. The final decision was to implement an NMOS transistor device due to several
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distinct advantages over the other devices. The NMOS transistor is a stable device that
can easily control currents with changes at the gate voltage. This device is also more cost
effective than other researched items, and is readily available. The device also has a high
switching frequency, which is more than sufficient for the application. The driver will
receive a controlling signal with a calculated frequency from the digital controller.
LED DRIVER COMPARISON
LED22V1A2DW
LM2623
CT2100-400
Gerneral Purpose Boost Quad Solid
Converter
State Relay
Device
LED Controller
Manufacturer
Design Complexity
Sufficient Equipment
Cost of Total Materials
Availability of Components
Versatility of Design
Power Efficiency
Mean Score
Normalized Score
Analog Technologies Inc.
National Semiconductor
3
3
3
3
4
5
3.50
0.88
3
3
4
3
4
4
3.50
0.88
Aeroflex
ALD1103PB
MOSFET
Advanced
Linear
Devices
2
3
2
3
4
3
2.83
0.71
5
3
5
5
3
3
4.00
1.00
Table 6: Pugh’s Method evaluation of LED drivers
Comparing viable LED driver devices, it is apparent that a MOSFET would be the most
cost effective and easy to implement. The team has the most experience with an NMOS
device from previous drive applications, thus its high rating on design complexity.
Researching several NMOS integrated circuit chips led to the following comparison of
the most feasible shown in Table 7.
MOSFET DRIVER COMPARISON
Device
Manufacturer
Drain Current Rating
VDS Rating
Threshold Voltage
Cost
2SK2549
TOSHIBA
2A
16V
1.1V
MMBF170
Diodes Incorporated
800mA
60V
3V (max)
0.78
0.1
Table 7: Pugh’s Method evaluation of LED drivers
The LED driver will be the MMBF170 by Diodes Incorporated due to its high voltage
rating, and satisfactory drain current. This component is also cheap compared to the
Toshiba MOSFET.
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Voltage Regulator:
The problem with the CKP signal is that the voltage level fluctuates from 27V at idle to
over 45V near redline. The ALD1103PB was the MOSFET chosen to regulate input
voltage to the digital controller due to its ease of implementation and the ability to model
it in the PSPICE software environment. Another reason this device was chosen is due to
the team’s previous experience through lab implementation. The voltage regulator at the
input of the Ald1103PB divides the voltage as explained in the CKP test section.
The resistors chosen for the voltage divider stage and the voltage regulator stage are of
the values shown in Figure 6.
These resistors are rated at 1/4W. The calculations
determining the power rating are shown in Calculations 2.
Calculations 2:
Resistor 1 Power Rating Calculation:
V 1  27V  1.345V  25.655V
V 2 25.655 2

 .019W
R
33k
Resistor 2 Power Rating Calculation:
V 1  5.621V  0  5.621V
V 2 5.6212

 .002W
R 12kk
Resistor 3 Power Rating Calculation:
V 1  1.627V  1.308V  .319V
V 2 .319 2

 50W
R
2k
Resistor 4 Power Rating Calculation:
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V 1  1.308V  0  1.308V
V 2 1.308 2

 208W
R
8.2k
Triple Clamp Design
For the top triple clamp, all of the constraining is done at the seven-degree hole in the
rear. It is this hole that the steering shaft ties the triple clamps to the frame. Therefore,
the constraint that effects the surface on the inside of the rear seven-degree hole is no
translation of, or rotation about, the x or z directions. The translation in the y direction is
constrained by the top surface around the rear seven-degree hole. It is on this surface that
a bolt will be seated which pulls the assembly together, thus constraining translation in
the y direction. There are also constraints on the surfaces inside the bolt holes that will
be used to provide clamping force. In the top triple clamp there are eight holes that will
have bolts going through them to provide this clamping force. The rigid connection
constraint was used on the inside surface of each of the clamping bolt holes. This models
the part as if there are bolts in the holes as there will be in the real part.
The loading is based on a worst-case scenario of a head on collision. The force applied to
the top triple clamp in this scenario is in the positive z direction acting on the front
surface of the fork tube holes. The direction is based on the moment created about the
lower triple clamp. The force that is applied for this scenario is 5969 lb acting at each of
the fork tube locations. There is also the need to address the vertical force acting on the
top triple clamp. The vertical force is acting in the positive y direction and assumes a no
slip condition between the triple clamps and the fork tubes. The force is derived also
from the worst-case scenario. This resulted in a force of 979 lb acting as a surface force
in the positive y direction on each of the fork tube holes.
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Figure 11 is the constraint and loading schematic for the top triple clamp. The constraints
and loading positions are chosen on the basis of creating a model that most effectively
resembles how the forces will actually apply to the part.
Figure 11: Constraint and Loading Schematic- Top Triple Clamp
For the lower triple clamp, all of the constraining is done at the seven-degree hole
in the rear. It is this hole that the steering shaft ties the triple clamps to the frame.
Therefore, the constraint that effects the surface on the inside of the rear seven-degree
hole is no translation of, or rotation about, the x or z directions. The translation in the y
direction is constrained by the lower surface around the rear seven-degree hole. It is on
this surface that a bolt will be seated which pulls the assembly together, thus constraining
translation in the y direction. There are also constraints on the surfaces inside the bolt
holes that will be used to provide clamping force. In the lower triple clamp there are six
holes that will have bolts going through them to provide this clamping force. The rigid
connection constraint was used on the inside surface of each of the clamping bolt holes.
This models the part as if there are bolts in the holes as there will be in the real part.
The loading is based on a worst-case scenario of a head on collision. The force
applied to the lower triple clamp in this scenario is in the negative z direction acting on
the back surface of the fork tube holes. The direction is based on the moment created
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about the top triple clamp. The force that is applied for this scenario is 8381 lb acting at
each of the fork tube locations. There is also the need to address the vertical force acting
on the lower triple clamp. The vertical force is acting in the positive y direction and
assumes a no slip condition between the triple clamps and the fork tubes. The force is
derived also from the worst-case scenario. This resulted in a force of 979 lb acting as a
surface force in the positive y direction on each of the fork tube holes.
Figure 12 is the constraint and loading schematic for the top triple clamp. The constraints
and loading positions are chosen on the basis of creating a model that most effectively
resembles how the forces will actually apply to the part.
Figure 12: Constraint and Loading Schematic- Lower Triple Clamp
Based on the analysis, both parts are structurally sound with a force based on a 7G
impact. The industry standard for impact testing is no yielding due to a 3G impact.
Since both parts are below yielding due to a 7G-impact force, it is safe to say that at 3G’s
there is a substantial factor of safety. The industry specification information was
acquired though Derek Yuen of X-Test Incorporated. The fatigue limit was calculated
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based on a cyclical 3G vertical input. The number of cycles with this very intense force
was 67000 cycles. Figure 13 shows the von Mises Stress based on a 7G horizontal
impact scenario on the top triple clamp. Figure 14 shows the displacement magnitude
based on a 7G impact scenario on the top triple tree. Figures A-1 through A-4 in
Appendix A show the von Mises Stress and displacement magnitude based on 7G and 3G
impact scenarios for the lower triple clamp.
Figure 13: Top Triple Clamp- von Mises Stress based on a 7G horizontal impact scenario
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Figure 14: Top Triple Clamp- Displacement magnitude based on a 7G horizontal impact
scenario
There were some preliminary design criteria that influenced the outcome of the triple
clamp designs. The decision to rake the front of the motorcycle out 7 degrees, and also
the use of 55-millimeter diameter top tube inverted forks, conversion to a mid-glide front
end, while also designing around the stock Harley Davidson Sportster frame. The stock
triple clamps are made of cast aluminum, so the team decided that the replacements
would be billet 6062-T6 Aluminum that is relatively easy to machine, polish and anodize.
The top clamp is 1.75 inches thick, while the lower is 2 inches thick.
The rake angle was defined by the 1-inch diameter hole in the rear of each clamp. This
hole has a steering shaft mounted through it, which assembles the triple clamps to
steering stem. This hole is at a 7-degree angle from vertical. The bearing mating
surfaces must also be perpendicular to the hole angle.
Conversion to a mid-glide front end in the design drove the center-to-center distance
between the fork tube hole locations. The mid-glide center-to-center distance is 8.065
inches; this drastically widens the front end of the motorcycle and in combination with
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the larger diameter forks, it changes the styling of the motorcycle to look more like a big
bike.
The three-bolt pattern was chosen to distribute the clamping force evenly across the
thickness of the part. The design incorporates 5/16-18 socket head cap screws to apply
this clamping force to the steering stem and the fork tubes.
The final constraint is the triple clamps must be aesthetically pleasing. As the triple
clamps are a very visible surface of the motorcycle, they must look good while still being
structurally sound. Figure A-5 in Appendix A illustrates the top and lower triple clamp
designs.
Swing Arm
The team initially started designing a replacement swing arm for use on the 175th
chopper. The goal was to produce a swing arm that would be a direct replacement for the
stock component and be much more visually appealing. We started the design with the
goal of using 6061 T-651 aluminum as the construction material. Since 6061 is not a
direct replacement for mild steel, extra care was taken to retain as much material as
possible, and yet fit a 190mm wide tire. Since the goal was to produce a direct
replacement, the stock pivot bearings were designed around. They are the blue bearings
in Figure 15. The stock shock mounting points were utilized as well so that a stock ride
height could be retained if so desired.
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Figure 15: Sportster swing arm
Since this component needed to be aesthetically pleasing we tried to design the chain
tensioner so that it was much less obtrusive. This was accomplished by utilizing two
“pull blocks” which the axle passes through. These blocks have threaded holes that allow
two socket head cap screws to be thread into them pulling the axle toward the back of the
bike and tensioning the chain. The green block represented in Figure 15 would be pinned
in place allowing the SHCS to pull against them as the chain was tensioned.
Ultimately the team decided that due to the size and complexity of the swing arm we
would only attempt to produce one if time allowed. This conclusion was based on the
ability to utilize the stock swing arm, with some minor cosmetic modifications.
Wheel Design
The first front wheel design the team developed is illustrated in Figure 16. The design is
made out of three pieces. The thicker piece that can be seen is from the wheel blank and
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is the structural support of the wheel. The lighter colored piece is a decorative attachment
to the blank, created to emulate a tiger claw to go along with the tiger theme of the bike.
The attachment would have a corresponding piece on the opposite side of the blank. The
team first considered making the attachments out of aluminum; however, aluminum was
deemed not feasible as it is too heavy and too difficult to machine. The next idea was to
make the attachment out of composite; this too was deemed not feasible, as a mold would
have been exceedingly difficult to make. As a result, the team vetoed this design.
Additionally there was some speculation the design it self was not structurally sound and
would fail analysis. Therefore analysis was not performed on this wheel or hub.
Figure 16: Original wheel design
The finalized front wheel design is illustrated in Figure 17. The orange outlines are
present to increase the visibility of the cut details in the illustration. For analysis on the
wheel, the team used an impact load of 6Gs, a full compression load of 6Gs and a
maximum torque load of the braking force plus the tractive effort applied at the bead of
the wheel. The industry standard for testing impact loads and compression loads is 3Gs.
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By using 6Gs we have allowed for a reasonable factor of safety. The material used for the
analysis was 6061 Aluminum, with a maximum yield stress of 40,000 psi and the
ultimate tensile stress of 45,000 psi. Calculations involved in this analysis are located in
Appendix B under Calculation set A.
Figure 17: Final wheel design
The rear wheel will stay solid with the exception of the mounting points for the rear hub.
A 5-bolt pattern was chosen because of the size of the hub and the amount of force
exerted on it. The loading for the analysis was performed in the same way as for the front
wheel. Figure A-11 in Appendix A illustrates the rear wheel design.
Wheel Hub
The wheel hub was analyzed by using of a torsion test. The break rotor bolt holes were
loaded and held on to by the wheel mounting holes; the same torque as was used for the
wheel was used. Figure 18 shows the wheel hub.
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Figure 18: Wheel hub
Drive
The Sportster's stock drive line consists of a belt drive system made up of three
key parts, a front pulley, a rear pulley and a Kevlar belt. The front is a 28-tooth pulley
while the rear is a 68-tooth pulley. The team decided to eliminate the belt in favor of a
#530 chain. This was done for a couple reasons. A Belt, while providing a smoother and
quieter operation is much wider then a chain. The reduction in width is required in order
to fit a 190mm wide rear tire. The second reason for upgrading to a chain drive was to
increase the overall durability of the drive line. Chain drives can stand much harsher
applications of torque, and shock loading. The chain selected was based on the power
out put of the choppers engine. The first step in upgrading the overall drive line was to
determine a final drive ratio. The stock drive ratio is 2.43:1, which was calculated by
dividing the driven pulley by the drive pulley. The team decided to stay close to the
original final drive ratio since the new rear tire will be slightly smaller in diameter then
the stock tire, this alone combined with a 2.5:1 ratio would make the bike a little bit
easier to start off with while still maintaining a respectable top speed.
The first component that required a redesign was the output sprocket. This is the
drive sprocket that attaches to the transmissions output shaft. Due to the size of the
retaining nut on the transmission output shaft, the out put sprocket had to be designed
much larger then typical front sprockets. Typical front sprockets are no larger the 16
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teeth, while the one we designed was a 20 tooth. Figure A-10 in Appendix A illustrates
the 20-tooth sprocket.
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Appendix A
Figure A-1: Lower Triple Clamp- von Mises Stress based on a 7G horizontal impact
scenario
Figure A-2: Lower Triple Clamp- Displacement magnitude based on a 7G horizontal
impact scenario
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Figure A-3: Lower Triple Clamp- von Mises Stress based on a 3G vertical impact
scenario
Figure A-4: Lower Triple Clamp- Displacement based on a 3G vertical impact scenario
Project Number 05912
Figure A-5: Top and Lower Triple Clamp Design
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Figure A-6: Impact loading
Figure A-7: Von Mises Stress based on impact load in A-6
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Figure A-8: Torsion loading
Figure A-9: Von Mises Stress based on torsion load in A-8
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Figure A-10: 20-tooth sprocket
Figure A-11: Rear wheel design with hub
Project Number 05912
Appendix B
Calculation set A
Loads
F=m*a
W = 780 lbsf, bike plus rider
m = 780 lbsf / 32.1704 ft/s2 = 24.2459 lbsf s2/ft
a = 6 * 32.1704 ft/s2 = 193.0224 ft/s2
F = 24.2459 lbsf s2/ft * 225.1928 ft/s2 = 4680.00 lbsf
Torque
Tractive Effort-
P =  * m * t = 1 * 10.944 * 612 = 608.884 lbsf
R
11
≡ Overall mechanical efficiency = 1
m ≡ Overall gear ratio = 10.944 (1st gear)
t ≡ engine torque = 51 ft lbs = 612 in lbs
R ≡ tire rolling radius = 11 in
Braking ForceF = m * a = Fr
Fr = fr * N
a ≡ 3 Gs = 96.5112 ft/s2
m = 24.2459 lbsf s2/ft
Fr ≡ Force of friction = 2340.00 lbsf
fr ≡ Coefficient of friction = .8
N ≡ Normal Force = 2925.00 lbsf
Total Torque = 608.884 + 2925.00 = 3533.89 lbsf
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Appendix C
Weighted concepts evaluation: Fuel Tank
Attributes
1
2
3
4
1. Price
X
2. Uniqueness
X
X
3. Design concept
X
X
X
4. Ease of manufacture
X
X
X
X
5. Fulfills project goals
X
0
X
0
X
0.5
X
2
5
X
5
1
>$1,000
2
<$1,000
Looks as
Look less
unique as a
Uniqueness unique then a
standard
"peanut" tank "peanut" XL
tank
Design
Concept
0
3
0.27
0.5
0
0.5
0.05
0
0.5
0.5
0.05
0
2
2
0.18
0
5
5
11
0.45
1
3
<$700
4
<$400
5
No cost
Looks as
unique as
standard XL
custom tank
Looks as
unique an
average
custom
choppers
Most unique
tank
imaginable
Does not look
Looks similar Looks exactly
Does not fit Does not fit like concept
to concept
like concept
concept and concept, but drawings, but
drawings,
drawings,
does not look looks good on fits concept
looks good on looks great on
good on bike
bike
and looks
bike
bike
good on bike
Custom
design and
custom built
Not on the
Already on the Already on the
market, but
market, but market and
can be
not readily
readily
manufactured
available
available
in bulk
Do nothing,
Fulfills project leaving a
goals
standard XL
883C look
Make a bike
Make a bike Make a bike
that meets
that fits most that meets all
some of the
of the goals of
goals of
goals of the
the project
project
project
Ease of
manufacture
Figure C-2: Attribute rating scale
Weights
3
Figure C-1: Attribute comparison
Price
TOTAL
Project Number 05912
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Attribute
Weight
Stock Tank Commercial Tank Custom Tank
Price
0.27
5
3
1
Uniqueness
0.05
3
4
5
Design Concept
0.05
1
4
5
Ease of manufacture
0.18
5
5
1
Meets project goals
0.45
1
5
5
Score
2.91
4.36
3.18
Purchase Aftermarket Tank
Evaluate each additional concept against
the baseline, score each attribute as: 1
= much worse than baseline concept 2 =
worse than baseline 3 = same as baseline
4 = better than baseline 5= much better
than baseline
Fabricate Tank
Purchase Custom Tank
Figure C-3: Alternative comparison
Sufficient Student Skills
3.0
2
3
Sufficient Shop Equipment
3.0
2
3
Economic Feasibility
3.0
4
5
Cost of Materials
3.0
4
5
Cost of Purchased Components
3.0
4
5
Schedule Feasibility
3.0
1
3
Task Time
3.0
1
3
End user satisfaction
3.0
3
1
Technology Feasibility
3.0
2
3
Meets intermediate milestones
3.0
3
3
Meets PDR requirements
3.0
3
3
Meets CDR requirements
3.0
3
3
Mean Score
3.0
2.7
3.3
90.0%
80.0%
100.0%
Normalized Score
Figure C-4: Pugh’s Method for fuel tank
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Chain drive
Evaluate each additional concept against
the baseline, score each attribute as: 1
= much worse than baseline concept 2 =
worse than baseline 3 = same as baseline
4 = better than baseline 5= much better
than baseline
Smaller belt drive
Existing belt drive
Project Number 05912
Sufficient Student Skills
3.0
3
3
Sufficient Shop Equipment
3.0
3
3
Economic Feasibility
3.0
2
4
Cost of Materials
3.0
2
2
Cost of Purchased Components
3.0
2
5
Schedule Feasibility
3.0
2
4
Task Time
3.0
2
4
End user satisfaction
3.0
3
2
Technology Feasibility
3.0
3
5
Meets intermediate milestones
3.0
3
4
Meets PDR requirements
3.0
3
4
Meets CDR requirements
3.0
3
4
Mean Score
3.0
2.6
3.7
81.8%
70.5%
100.0%
Normalized Score
Figure C-5: Pugh’s Method for driveline
Project Number 05912
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http://motorcycles.about.com/cs/choppers/a/choppers.htm
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http://designserver.rit.edu/