Observation
• VW controls
Bike Tool Evaluation
HUMF 3505/5505, Fall 2011
Team Members:
Amy Langenfeld
Stephen Whitlow
Alan Wyman
Agenda
• Use and features of the bike tool
• Heuristic review
• Focus group opinions
• Survey perceptions
• Analysis
• Recommendations
Multi Hex (Allen) Wrench Set
• Multi Hex (Allen) Wrench Set used for working with multiple
sizes of hex bolts
• Compact tool that is stowed in seat-bag or jersey pocket
Multi Hex (Allen) Wrench Set
• Most common use cases:
• Component adjustment such as seat post and clipless
pedals
• Road side repairs
• Installing accessories such as water bottle carriers and rear
racks
• Not likely to be used by professional bike mechanics
Multi Hex Tool Use
• Rotate selected wrench out for use
• Grasp body of the tool
• Rotate clockwise to tighten or counter-clockwise to loosen.
All hex wrenches
With screwdrivers
Multi Hex (Allen) Wrench Set
• Wrenches aligned in two layers, one on top of the other.
• Layers are mounted to different ends of the tool body
• Can be rotated out 90 or 180 degrees
• Higher torque or rapid low torque application, respectively
• Two largest wrenches are on the top level
• (6 mm, 5 mm)
• Smallest five sizes are on the bottom
• (4 mm, 3 mm, 2.5 mm, 2 mm, 1.5 mm)
Heuristics – Visual
•
•
•
•
Compact size for storage and transport
Rounded ends
It’s black and silver.
Individual wrenches are visible from the top of the tool
• Allows user to identify the fairly unique hexagonal shape from the
hex bolts to manipulate.
• Wrench sizes are etched into back of tool
• Difficult to discern in many lighting conditions due to poor
contrast
• Individual wrenches include etched labels
• Difficult to read due to low contrast
Heuristics – Feedback
• Visually can see that tool is in the matching opening
• Tactile response that the tool is fully seated in the screw or
bolt
• Visual feedback that you can tell if it’s moving
• Kinesthetic feedback whether it’s inserted properly
• Difficult to map bolt size to wrench size
• Trial and error approach with multiple steps on each trial
Heuristics – Conceptual Model
• Suggests a similarity to a common tool, the Swiss Army knife,
which leads user to expect to rotate out different tools
• This is a tool. It will handle a variety of sizes of screws with hex
heads
• The tips unfold to form a familiar shape like a normal
screwdriver
• You can figure out how to pull the individual tools out because
they are visible.
• The number of possible actions is limited.
Heuristics – Behavioral Mapping
• Sizes of wrench/screwdriver tips afford visual map to the
screws.
• The rounded ends afford turning out to the familiar shape.
• It looks like a tool and it functions as a tool.
• Large flat-head screws suggest wrenches can be detached
Heuristics – Economically Affordable
• Compared to a set of matching tools, it seems to be economical.
• This design trades-off economy and stowability for usability
• Very inexpensive and an easy way to fix your bike.
Evaluated version
$6
Park Tool
$8
Craftsman
$12
Individual wrenches
$20-40
Heuristics
• Safety:
• No locking mechanism, could fold on the user’s knuckles
• Tool shape could most appropriately be described as a
rectangular solid with relatively sharp edges
• Durable:
•
•
•
•
All metal construction
Very heavy and difficult to break
Stainless steel body and screws resist rusting
Heavy gauge and do not flex when applying force
Heuristics
• Comfortable:
• Handle is good size for most hands
• No padding/insulation
• Irregular surface makes a tight grip uncomfortable
• Functional:
• Three tips are readily available. The others need to be unfolded
after moving the first three out of the way.
• Relatively short lever arm makes high torque difficult
• It works to adjust your bike, in an emergency situation
Focus Group Likes
•
•
•
•
All wrench sizes are present and won’t fall out and get lost
It is a simple tool
Solidly built and durable
Positive contact-- not likely to round out bolt
Focus Group Dislikes
• The wrench length is fixed-- if you have limited clearance
you are out of luck
• Wrenches do not lock in place
• Too heavy
• Single point of failure-- if screws fall out
• No margin for error for insertion into hex bolts-- has to
be straight in
Focus Group Changes
•
•
•
•
Have wrenches lock in place
Make it more like a pocket knife
Add a light to illuminate hex bolt
Make it easier to remove them-- without another tool -- flip
something and take it out
• Add a cable puller/tire levers-- more functional bike tool
• Modified end to increase margin of error for insertion-- like a
Craftsman ball-end hex key
Perceptual Survey
Strongly
Disagree
Strongly
Agree
1
2
3
1
2
3
Confident use
Easy to use
Quickly learned
Use frequently
Well integrated functions
Cumbersome to use
Need the technical support
Learn quickly
Too much inconsistency
Unnecessarily complex
n=3
4
5
Summary of Analysis
• Pro
• Compact design for safe stowing in seat bag.
• Highly visible design that is generally simple to
understand
• Includes most commonly user wrenches for bike
applications
Summary of Analysis
• Con
• The smallest two sizes are rarely, if ever, used in
common applications
• One of the most commonly used wrench sizes (4mm)
is in the second layer
• Given the nature of the mounting mechanism, the
whole layer or wrench will frequently rotate out
together requiring the user to rotate back all but the
desired wrench size.
• The ends of the wrenches are somewhat sharp and
pose a tearing hazard to the inner-tubes that
frequently stowed in a seat bag
Summary of Analysis
• Y-tool is far more usable due to inclusion of 3 most
frequent sizes and better hand grip
• But it is not appropriate for stowing.
• Best hex wrench usability achieved by individual shop
tools
• This model was designed for economy and stowability,
but not usability.