Torque+contoled+fixed+gear+bike+motor

=Introduction= toc

If you've ever ridden a fixed gear bicycle you know that it quickly becomes addicting. Because every movement of the pedals directly correlates to the motion of the bike the rider quickly develops muscle memory for accelerating, decelerating, or just cruising. In short, as one gets familiar with a bike and its gear ratio, it quickly feels like the rider and bicycle become one. My question is, what if you can create something that will allow you to go accelerate faster, cruise longer, and stop on a dime (usually the hardest/most dangerous part of the bike) without losing that connection between rider and machine. I'd like to try to adapt an existing design for a bike motor to accomplish this. Instead of using a conventional throttle, I envision retrofitting a bicycle with torque or pressure sensors that will read what your body is trying to do and have the engine act accordingly. I believe the best way to do this will lie in adapting the throttle of an engine to the acceleration, while creating either a pressure sensitive braking system or down-gearing the engine for deceleration. There's probably a lot of bugs but that's what I'm here to figure out!

=Overview=

__Module type:__ primary __Secondary modules:__ none yet

__Subjects:__ Mechanical Engineering, Sensors and Controls

__Labs/Clearances:__ none

__Materials:__ Bicycle Chainsaw motor [|Torque Sensor] more TBD

__Tools:__ TBD

=Expectations and Outcomes=

Upon completion of this module, Inventioneers should have a comprehensive knowledge of the following: Gear ratios and engine components Use of torque sensors/strain gauges

=Background and Definitions=

[|Throttle]
This will be the main difference between this concept and what has already been done for motorized bicycles. Instead of using a throttle controlled by the hands I will need to figure out a way to control the engine based off of the movement of the crank and the torque it creates.

[|Clutch]
A centrifugal clutch may be best because it only engages when the motor reaches a certain rpm threshold. With a fixed gear this might be important to prevent unwanted movement while stopped and the engine is idling. A [|chain saw engine] employ this, which may be a good source for a prototype engine The centrifugal clutch will also allow the bike to be ridden while the motor is off

A torque limiter, or safety clutch could be added to disengage the power to the motor when force is applied in reverse to the pedals. This is used in lawn mowers.

1) Friction
Possible Problems: Smooth road tires may not allow mechanism to work effectively and the friction mechanism will wear out the tire

2) Chain
Possible Problems: would have to compensate to avoid excessive spinning of the pedals

3) Hub
Possible Problems: harder to build for a 1st run, expensive

=Resources=

Advice
[|Motor Cicycling Forum] This is a discussion board where members post photos and discuss results of certain projects involving bicycle motors. Here you can find many example projects as well as ask for help.

Materials and tools
[|Bike Saviours] This is the tempe based bicycle co-op. They are open from noon to 6pm every sunday and have a wide range of parts and tools that can be used. [|Maker Bench] Maker bench has all of the basic tools that may be needed for this project as well as some more advanced ones. This may be a good place to get help for the electronics and more complicated aspects of the project.

=Example Projects=

Instructables
[|Leaf blower engine powered bicycle] [|Weed wacker engine bike]

YouTube
media type="youtube" key="xeRsg3-Jy4c" width="425" height="350"

=Core Content=


 * only research has been done so far

=Notes=

Prior to 9/3- Came up with idea and conducted internet research 9/3- organized module layout 11/10- found out a very similar product exists after all, pedal assist bikes

=Collaborators=

Student:
Logan Van Engelhoven

=Ideas and Feedback=

links to look into:
[|torque sensor apps] [|sensor selection] [|Spokeless Bike (potential to attach engine)]