Bike to Shelf
Andy Lee
Mack Burgess
Mike Proscia
Josh Addison
April 27, 2012
Team 6
Abstracts
Our bike to shelf is coming along amazingly. The group has decided to focus on the
location of China and mainly the poor migrant workers. Our group decided on China because of
the large population and because this for some reason was not a popular location among the
class. As for this project finding exact customer needs was not easy. There were also not many
examples to compare our final design with either. Many of our customer needs were taken from
blogs, various news articles, and many other sources from around the internet. International
students from China around Penn State also gave our group some background information to a
cart and what were sold on the carts. Based upon our research we decided to divide the customer
needs into five main sections: inexpensive, easy to use, versatile, durability, easy to store. From
here we developed an AHP chart and determined the weight of importance of each category
referring back to the shelf. This was where we were able to determine that pricing will be the
main concern with the ease of storage the least of our worries. After this we did patent research
to find more information to what needs to be made and what not. This really gave us a basic idea
of new ideas from the original already available.
1.0 Introduction
Street vendors have been around selling many different types of products for many years.
However, street vendors face many challenges throughout this type of business. One massive
problem that street vendors face is in transportation. If the vendor travels while selling his
product, he must be able to move swiftly and efficiently while not losing or damaging his
product in any way. At the very least, the vendor must be able to transport his cart to and from
his home every day without suffering any major losses. The transportation method must be as
cheap as possible while still being efficient and long lasting. Another huge issue is space; if a
vendor has more space, then he will be able to carry more and subsequently sell more. The
vendor must find a way to carry as much of his product as possible without losing any of it and
without the product being too much of a burden for travel. The best way for these vendors to sell
their product is with the use of a bicycle. The bicycle allows for easy transportation and
movement and a storage compartment can be added to the bicycle for the vendor to carry more
of their product. A bicycle can also be long lasting and is not detrimental to the environment.
However, how much storage can be added on to the bicycle as well as how the bicycle should be
made must be considered to maximize the efficiency of this style of vending. This report will
outline the information and data we have found that would allow for the ideal bicycle for a
merchant. The style and storage would depend on what the vendor is selling; which varies from
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food to clothing. By analyzing factors such as customer needs, current patents, and how to use
and integrate the best products, we have created a bicycle with a storage compartment that a
vendor could use to sell his product.
1.1 Initial Problem Statement
Many street vendors are not efficient in the way they handle and transport their product.
Our goal is to assist the vendors by creating a bicycle that makes the transport of their product
easy and would allow a long lasting method for the vendor to sell their product. The bicycle must
also have a storage compartment for the vendor to hold his entire product. The storage
compartment must be big enough to hold all of the vendor’s merchandise (and more if possible)
but also be light enough so that it would not weigh them down too much and reduce the
efficiency of this style of vending. A balance must be found where the vendor can easily
transport his merchandise without the loss of any goods while still holding the maximum amount
of his product possible to maximize sales.
2.0 Customer Needs Assessment
Our customer needs was gathered through diligent research on the part of the team.
Finding exact customer needs unfortunately was not easy. The target consumers for this product
are poor migrant workers who live in China, whether in cities or small villages. As such there
was no capability on our team’s part to interview our main consumers for this product. Instead,
we found blogs and newspaper articles relating first-hand accounts of the lives of street vendors
and extrapolated customer needs, and their importance, from the various writings. Further we
have spoken to various Chinese students here at the university to give their insights on the wares
sold by the vendors and what their carts are usually like.
2.1 Weighting of Customer Needs
The initial customer needs list (Table 1) was determined by our team’s readings of firsthand accounts of the lives of migrant workers who are street vendors, and augmented by
interviews with the Chinese exchange students’ personal experience with them as well. The
hierarchical customer needs (Table 2) was determined by which customer needs could be
overlapped and lumped into a single category. The AHP charts were down by pairwise
comparison with each different customer needs category being given a weight of importance on a
1-9 scale. The numbers given to each category was determined by the importance of the
category, based upon our research. The ratings given to each of the categories are as follows:
Inexpensive, 9, Easy to Use, 6, Versatile, 8, Durability, 8, Easy to Store, 4. From there using an
AHP Chart (Figure 1) the weights of each category was determined.
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Table 1. Initial Customer Needs List Obtained from Background Research
Inexpensive
Easy to use
Versatile
Durable
Easy to Store
Under $300
Compatible with many bikes
Can hold variety of wares
Collapsible
Easy to Setup
Easy to Close
Light
Turn Easily
Storage Space
Table 2. Hierarchal Customer Needs List Obtained from Background Research
1. Inexpensive
1.1 Under $300
2. Easy to Use
2.1 Easy to Setup
2.2 Easy to Close
2.3 Turn Easily
3. Versatile
3.1 Can hold variety of wares
3.2 Storage Space
3.3 Compatible with many bikes
4. Durable
5. Easy to Store
5.1 Collapsible
5.2 Light
Inexpensive
Easy to Use
Versatile
Durable
Easy to Store
Inexpensive Easy to Use
1
3
0.33
1
1
2
1
2
0.2
0.5
Versatile Durable
1
1
0.5
0.5
1
1
1
1
0.25
0.25
Easy to Store
5
2
4
4
1
Total Weight
11
0.31
4.33
0.12
9
0.25
9
0.25
2.2
0.06
Figure 1. AHP Pairwise Comparison Chart to Determine Weighting for Main Objective
Categories
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Table 3. Weighted Hierarchal Customer Needs List Obtained from Focus Group and
Individual Interviews
1. Inexpensive (0.26)
1.1 Under $300
2. Easy to Use (0.17)
2.1 Easy to Setup
2.2 Easy to Close
2.3 Turn Easily
3. Versatile (0.23)
3.1 Can hold variety of wares
3.2 Storage Space
3.3 Compatible with many bikes
4. Durable (0.23)
5. Easy to Store (0.11)
5.1 Collapsible
5.2 Light
3.0 Revised Problem Statement
After analyzing the results, we have concluded that our next step is to decide on how to
make the shelf the most inexpensive as possible. The ability of the storage was the least of the
worries from the AHP charts. We noticed all of these factors from the highest ratings and lowest
ratings from the AHP charts.
4.0 External Search
At the moment our group has each individually researched different sections for the shelf
on the bike. We have selected a location in China and split the research into main points to get
the most of what the ideal shelf on the bike should be. Main points include like what it should be
made, dimensions, storage, and etc.
4.1 Literature Review
Online, we researched various things. What we mainly wanted to focus on was a simple
shelf that could do it all at an affordable cost. We researched things such as recyclable materials
to make a rough outline of the body for more eco-friendly purposes. We also researched ways to
produce the lightest trailer/shelf to make the design more compact and simple to maneuver.
Some other things we researched were model examples from around the internet, particularly
around the regions of China. We found that some of these model designs can be complex and
very hurtful for the environment. All the pricing of the shelf with be based on the material we
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choose to use and the amount we use; as our group cannot find a premade one to compare prices
too. Our ideas should please the consumers from affordability to cost.
China is one of the largest markets in the world with about 1,343,239,923 people within
the country. This makes it a perfect market to sell goods at an affordable cost. The products that
we looked at to make the trailer out of were metal and wood mainly. While these products are
not the eco-friendliness; we had to take into account our most important need the affordability.
Given these circumstances, metal and wood are our best bets since they are some of the cheapest
materials and will be very durable too. This also works to our group’s advantage as China is a
large exporter of those sorts of products (CIA.gov).
While China has a very powerful and dominate economy; our main targets were not those
sorts of people. The main focus for us was the middle and low class. It is believed that 816.2
million people are in the labor force and 13.4% of the population is in poverty (CIA.gov). This
is a fairly good amount for our population target too. In respect the vendors sell all sorts of items
from foods to clothing. These goods are usually inexpensive and cost about 20 Yuan ($3) or less
(china.org.cn).
Therefore our group has to worry about the affordability the most. While we do take into
account the eco-friendless our selections are very limited. There is a plus side though, and that is
the products we plan to use to product the trailer are all surplus products made/grow within the
country.
4.2 Patent Search
We gathered our patent information by using Google Patents. By seeing these patents, we
know what features we can copy and which we cannot. This ability helps us too as now our
group understands what we exactly need to do and not to do.
Table 4. Art-Function Matrix
FUNCTION
ART
An item with
wheels
attached and
can be used to
transport items.
A cart that is able
to fold up for easy
storage and simple
to carry around.
Presents a trailer
like object that can
haul things
around. Can be
modified between
“transport” and
“operational”
modes.
Example: portable
bike
Non- Powered
Transportable Cart
Portable Cart
A folding carrier
assembly converts
to a bike trailer, a
three-wheeled
jogging stroller
and a four wheeled
casting stroller.
The carrier
assembly has a
low main frame
A cycle trailer
comprising a
lightweight frame
supported on a pair of
road wheels and
having a draw-bar for
attachment to the
towing cycle.
7322586B1
6270092B2
Transportable Wood
Fired Oven
Folding Bike Trailer
Bike Trailer
0258107A1
6199549B1
7172206B2
3877723
US1458894
US3012796
US3829125
US4274649
US4307893
5
4.3 Benchmarking
The benchmarking part of the project gave us a few ideas to how our bike to shelf may
look like in the end. We displayed three homemade trailers and weighed each of the trailers
according to our four main features. The rating was on a scale of 1-5 with 5 being the best. The
three trailers were chosen because these really resemble closest to our final product. Overall the
most points received was the best trailer and that happened to be the Intervale Food Hub. That
was followed closely by the Ritual Roasters and in last place was the wagon.
Table 5. Benchmarking of Three Products
Feature
Bike Wagon
Ritual Roasters Bike Trailer
Intervale Food Hub
Pricing
The trailer is a bit pricy, but will
probably last the longest out of the 3.
It receives a 1.
Aesthetics
The Cart is dull and boring with no
colors. It receives a 1.
The Price of this trailer is
undetermined but for the looks of it
is probably cheaper than the first
because it is smaller. It receives a 2.
The trailer is a bit more colourful
that the previous 1 but still lacks
small details. It receives a 3.
Storage
The Wagon seems very spacious, but
may not be big enough for vendors.
It receives a 3.
Trailer’s Life
The wagon looks like it will last the
longest out of the 3. It is mostly
metal and outside seems strong
enough to take on unusual weather
conditions. It receives a 4.
The Food Hub seems to be made
the cheapest out of the 3. It looks
like some wood and plastic. It
receives a 2.
The Food Hub is colourful and
very unusual designed. It is
pleasing to the eyes. It receives a
4.
The Food Hub is large enough
for vendors and is the most
pleasing. It is also collapses
which is a plus. It receives a 4.
The Food Hub seems to be made
cheaply. It seems to not be
capable of bad weather
conditions. It receives a 2.
The trailer is small in size, but is
useful to a vendor. It has the
collapsible idea that our group likes
to have. It receives a 3.
The trailer is nice and compact, but I
do not know how long that hinges
will be able to last. Otherwise the
metal usage for the trailer is a plus.
It receives a 3.
4.4 Design Target
As a team we learned about what new concepts we need to develop for the consumers.
We are taking into account all the problems of our product from a financial standpoint to
dependability. We learned that for sure money will seem to be the main issue since what people
sells on these stands should benefit them and overcome the price paid for our trailer/shelf. We
are still in hunt for our final product to use on building the shelf to maximize the eco-friendliness
and cost. These ideas and more greatly helped us in our concept generation workshop. We also
know a rough dimension size of our final product that we will be able to use to help us in our
design.
.
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5.0 Concept Generation
1) Transportation.
Four wheels, two on each side of the cart.
Two wheels, one on each side of the cart.
One wheel positioned in the center and towards the back.
Three wheels positioned in a tripod
arrangement
2) Material options
Steel- very strong but heavy
Bamboo- cheap, readily available and ecofriendly
Aluminum-light, abundant in china, reasonably
inexpensive
Wood- strong but not the lightest
Plastic-lightweight, strong but less ecofriendly
3) Cart Features
Easily connect to any bike.
Collapsible. When the cart is not in use it will be able to easily
reduce its size to make transporting it easier
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Customizable. Include spaces for the user to easily attach stuff to the cart. Include holes in
supports at regular intervals so the user can tie stuff to the cart.
User reparable. By using parts that are easily replaceable the life of the cart will be extended.
Lightweight cloth canopy with the ability to fold down and protect the contents of the cart in bad
weather
Solid rubber wheels to prevent flat tires
Stabilizing posts and wheel locks for when the cart is in
use
Include an adjustable section on the hitch that connects
the bike to the trailer so that the cart will be level.
Wheels
Ease of Storage
Stability
Interior
Figure 2. Morphological Chart (not every feature has a drawing)
The concept generations that are not in the morph charts are excess ones. Most of those are
repeated again in the morph chart.
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6.0 Concept Selection
After we developed our concepts, we picked the best out of each category. We then made
a few Pugh Charts of our selected concepts and lined them up with our important criteria’s. Each
of our criteria had weights (from the AHP chart). We then ranked features against each from -1
to 1, -1 being worse than the selected 0 row, and 1 being better than the selected 0 row.
Whichever ended up with the highest total had the highest rank. We did not always use our
highest ranked feature for our final concept though.
Pugh Chart
7.0 Final Design
After we looked over our charts and our data, we determined the features that we wanted.
One of the most important features, determined by the AHP charts, was that the cart had to be
cheap. We thought about endless possibilities on how to make the product cheap. While our
product is not a small size we had to really play around the material selections. Choosing nickel
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as the best bet to meet all of our requirements. Another big thing was usage of the trailer. Here
we went with all of the shelves being able to fold and compress together. This way in the end it
turns to more of a box with wheels on the end for ease of usage. As for really helping the world
out; our cart really does not do that very well. Most of the materials selected for the cart were
plentiful materials in China. This way the production and cost would be more efficient. While all
of the materials could be reusable in the end the cart should last for about 10+ years with the
exception of the tires.
7.1 Materials and Material Selection
In order to find the proper material to build the cart out of, we focused on stiffness,
strength, and density weighing the importance of each shown in our AHP chart (table 1). We
used the AHP chart to rank the importance of these properties in order to find the best material to
use to build our cart.
We considered the non-discriminating parameters, discriminating parameters, and go/nogo parameters to narrow the choices for our material selection to two different aluminum
materials, standard A36 steel, and a nickel alloy. These materials vary in cost, strength and
durability and all of them must be looked at and considered to properly meet the needs of the
consumer while still being cost effective. Some properties of each material are shown in the
table. The standard properties of each material are shown in the table 2.
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The final material was selected for the cart based on the properties of the materials. We
created a weighted decision matrix from our AHP chart and the properties the materials and
weighted which material would best fit our needs in creating a successful cart. Our AHP chart
showed strength and density to be the biggest factors in terms of properties. Cost was also an
important factor shown in our customer needs. Because of this, we had to make sure that the cost
of the material would be reasonable while still being versatile and durable. The stiffness was
found to be slightly less important but was still considered because they would be ideal to have if
possible in the final selection of the material. Nickel showed to be the strongest in strength,
hardness, density, and Young’s Modulus of elasticity. The shear modulus data for Nickel was
unavailable so there is uncertainty on how rigid the Nickel alloy is. Nickel is very abundant and
inexpensive as shown by it being a component of one of the lower forms of currency in the
Unites States. This means that it should be abundant at a cheap price. Aluminum is the most
expensive and would be least effective to use. Steel was harder and stronger than the steel alloy
and is also an affordable method to build the cart but is not as strong as Nickel. Nickel is also
used to make stainless steel so it is both durable and versatile.
We ultimately decided to use Nickel to develop our cart because it is cost effective and
fits all of our needs we found in our AHP chart.
Table 6. AHP
Stiffness Strength Density Sum
Weight
Stiffness
1
0.33
0.5
1.83 0.161518094
Strength
3
1
2
6
0.52956752
Density
2
0.5
1
3.5 0.308914387
Total
11.33
Table 7. Typical Material Properties
Yield Strength
Ultimate Strength
Hardness
Young's Modulus of
Elasticity
Density
Shear Modulus
Units
psi
Nickel 188
Alloy
66700
psi
Brinell
137000
168
A36 Steel
36300
5800079800
150-180
GPa
g/cm3
GPa
232
8.98
N/A
200
7.85
79.3
11
6061 Aluminum
T-6
40000
2024
Aluminum
47000
45000 psi
95
68000
120
68.9
2.7
26
73.1
2.78
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Table 8. Weighted Decision Matrix for Final Material Selection
Nickel 188 Alloy
A36 Steel
6061 Aluminum
T-6
2024 Aluminum
Psi
Norm .16
66700
1
36000 0.539730135
E
(GPa)
232
200
40000 0.59970015
47000 0.704647676
68.9
73.1
Norm .53
g/cm3
Norm .31
Total
1
8.89
1
1
0.862068966 7.8 0.877390326 0.802713547
0.296982759
0.315086207
2.7
2.78
0.303712036 0.360906148
0.312710911 0.393073084
7.2 Scampers
Substitute (S). What could you substitute?
Use steel instead
Combine (C). What could you combine`?
Nickel and steel = additional strength and makes it resist corrosion (rust).
Adapt (A) What could be adjusted to suit a purpose or a condition?
Steel is cheaper but not stronger. The best option is to mix the 2 metals but would
increase the cost in the downside.
Modify (M). What would happen if you changed form or quality?
If we decrease the amount of either metal our cart would be smaller and cheaper.
If we increase the amount the opposite of the cart would happen meaning larger
and more expensive. Our shape of the cart can’t really be changed due to what the
group thinks that all of the components now are needed.
Put (P) to other uses. How could you use it with a different purpose?
Our trailer can be just as just human power meaning that the bike is not exactly
necessary. It can also be used to simply just carrying things around the city/town.
It can also be used as a storage method too.
Eliminate (E). What could you subtract or take away?
The most we could subtract is really the amount of shelves in each shelf. Another
possibility is also to remove the roof, but that is a vital part of our trailer design.
The kickstands could possibly go away, but the trailer will always be at an angle
though when in resting position. If the roof were to go away then there would be
no point to make the roof be able to slide up and down so the components for that
can go which are just 4 adjustable latches.
Reverse (R). What would you have if you have reversed it?
If we reversed the process we would have the same product but the wheels and
hitch are up in the air. If this were turned inside out the product would never work
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because the latches then would never match. Our design is a bit complex but
everything has to be in this order. Any modifications here would only be minor.
7.3 List of Materials
Table 9. List of required materials and components
Qty. Description
7
Invar (Alloy 36) 12”x24”
2
Recycled Plastic Lumber
(8”x6’x½ “)
2
Spoked Wheels (16”)
Total Cost:
Catalog #
4287K13
8506K38
Vendor
McMaster Carr
McMaster Carr
Total Cost
$486.50
$50.46
29635T32
McMaster Carr
$37.28
$574.24
Table 10. Contact information for suppliers of required Materials
McMaster Carr Supply Co.
473 Ridge Rd.
Dayton, NJ 08810
(732) 329-3200
7.4 Cost and Life Cycle Cost
Positive projections of the durability of this cart put its term of use at upwards of 10
years. As of March 2012, the inflation rate in China is at 3.6%. Therefore we will round up to
4% inflation rate in order to give ourselves a margin of error. An estimation of the total price of
the cart is necessary, after costs of materials, assembly, shipping, and markup we estimate that
the final price will be around $800, neglecting price change from bulk discounts. An average
street vendor brings in approximately 400 RMB ($63.44) a day, half of which we assume is put
towards fresh goods. All these factors will affect the Life Cycle Cost.
Cost Items
Initial Cost
Maintenance
Income
Product Life
Discount Rate
Present Value of Future Income
Street Vendor Cart
$800
$25/year
$63.44/day
10+ years
4%
$15500.00
As this shows the amount of money that could be made over the life span of this product far
outstrips the initial cost, making it a smart buy for the consumer.
8.0 Conclusion
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After conducting research, finding customer needs, and assessing the area for the best and
cheapest material, we were able to develop the best possible model for the people. By assessing
factors such as climate and available natural resources, we were able to develop a bicycle cart
that could efficiently move around most terrains. We also made it versatile in the height and how
the shelves can be placed on the bike. We made sure to develop a bike that is long lasting. We
tried to make the product affordable for all types of salesman interested in our product. By
focusing on keeping all of the goods sold on the cart safe as well as making sure transportation
would be quick and easy, we were able to create a great product that would sell well on the
market.
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