Rishi Savaliya, Mitch Reid, Kelsey Barrera Team ReMaKe
Define the Problem Time Management Survey Brainstorming Research Donation Letters Existing Solutions Group Solutions Criteria and Constraints Select an Approach Design Proposal Material Selection First Prototype Second Prototype Third Prototype Final Product Summary
Problem Statement According to the US Department of Transportation’s National Highway Traffic Safety Administration (NHTSA), approximately 57 million people in the United States rode a bicycle in the year The first bicycle that used a chain was invented in This resulted in the problem of bicycle chains falling off the gears. In a class of 27 students, 20 agree that bicycle chains falling is a problem that occurs very often and should be solved.
Statement of Purpose Create a product that will prevent the chain from falling off the gear of a bicycle.
Survey population: 145 Goals of conducting our survey Target Market Information Multiple causes of falling bicycle chains Problem Justification Product Pricing
Age groups: 14 and under 15 to 25 Ride bikes on average of 1 to 5 times weekly
Determine what specifically causes chains to fall off Create possible designs No restraints All ideas welcome Build off of team member’s ideas for best preliminary design
Why do bike chains fall off? Decreased tension makes chain loose Misalignment of chain and sprocket Does not mean that bike can not be used
Explained reason for writing Asked bike manufacturers to donate bikes Schwinn Mongoose/Pacific Cycle Trek Bicycle Raleigh America Inc. Cannondale Bicycle Corp. Benefits to companies for contributions
Drive-shaft driven bicycle Eliminates chain Patent
Chain catcher for bicycles Does not prevent chain from falling Patent
Motorized bike with gear and chain cover Patent
Design 1
Design 2
Design 3
Design 4
Easy to use Aesthetics Functionality Material Cost Feasibility Adaptability
ConstraintWeightDesign 1Design 2Design 3Design 4 Ease of Use51525 Aesthetics21534 Functionality52444 Material31123 Cost41123 Feasibility31143 Adaptability41115 Total
Created a build process Completed material and cost analysis Created technical drawings for concept
SpecificationWoodPlasticSteelCardboardFoamAluminum Durability Cost Machinability Availability Aesthetics Total
Foam
Too large for bike Wheels did not align with chain Not a good material Difficult to construct Arms were weak and had little support
Created a new design Selected new material Wood
Design 5
ConstraintWeightDesign 1Design 2Design 3Design 4Design 5 Ease of Use Aesthetics Functionality Material Cost Feasibility Adaptability Total
Wood
ItemQuantitySpecificationsPrice Wood12" X 4" X 2'$1.98 Screws with Bolts2 packs of 31/4" – 20 x 3”$1.49 per pack Rubber BandsA ball of them Multiple sizes and strengthsAlready Owned Total--$4.90
Chain Alignment Chain must stay aligned with prototype wheels Drop Test See effect of various riding terrains on prototype Durability Test Chain stays aligned for a given period of time Rider Interference Prototype cannot prevent rider from pedaling properly
Many broken pieces Placement too close to wheel Interfered with pedal Grooves of base block too large for arm piece Grooves of wheel too shallow
Change dimensions Arm Wheel Base Create new piece Attachment Piece New Material ABS Plastic
ABS Plastic Rapid Prototyping Machine
Prototype with bike
ItemQuantitySpecificationsPrice Screws and Bolts2 packs of 31/4” – 20 x 3”$1.49 per pack Rubber BandsA ball of them Multiple sizes and strengthsPre-owned PlasticABS Plastic$53.50 Total--$56.48
Duration Test completed Passed Chain Alignment Test completed Passed
Plastic is layered Easier to break
New material Steel Aluminum New elastic Design is still the same
Design same as third prototype New material Steel Aluminum New elastic
Problem Statement Prevent bicycle chain from falling off gears Product compatible with single-speed bikes Adaptable to different bike frame thicknesses Meets the standards of criteria