Bicycle Instrumentation Hardware Steven Brendel Joe Rinek Eric Chan

Project Motivation The UC Davis Sports Biomechanics lab is currently conducting bicycle dynamics research – Emphasis on dynamics and rider control at low speeds Physical models of bicycle dynamics need to be validated by experiment Experimentation requires a fully instrumented bicycle for data acquisition

Project Goals Design hardware to mount sensors onto bicycle frame – Dynamic data required by researchers Front and Rear Wheel Rates Steer Angle, Rate, Acceleration Roll Angle, Rate, Acceleration Yaw Angle, Rate, Acceleration Install hub motor – Provide a constant velocity for rider-less experiments

Design Concept: Wheel Rate Sensors Wheel rates for each wheel are required Specifications: – Range: 0-20 mph – Resolution: 0.1 mph Idea: Replace a bicycle disk brake with an optical encoder

Optical Encoder Code Wheel mounts to a shaft to measure rotational speed Optical Encoder Module fixed to a stationary frame Laser beam from encoder module shines through transparent code wheel but is interrupted by tick marks as the wheel turns The interruption of the laser beam provides a digital signal of the wheel rotational speed Optical Encoder Module Code Wheel

Disc Brake Brake caliper fixed to bicycle frame clamps down on brake disc to slow bicycle Replace brake caliper with optical encoder module Replace brake disc with code wheel Bicycle will use V-brakes to provide braking

Mounting the Code Wheel Disc brakes have a standard hex bolt pattern to mount a 6” brake disc to wheel hub The hex bolt pattern will be drilled into a custom 6” code wheel from US Digital

Mounting the Optical Encoder Module Side View of Bicycle Fork Rear View of Bicycle Fork Code Wheel Mounting BracketWheel Hub Optical Encoder Module

Electrizing a Bicycle Converting a bicycle to electric power is not as easy as just putting on a motor In addition to the hub motor, there also must be a compatible controller, throttle, batteries, battery storage, and brakes with a motor cutoff switch The easiest way to obtain this set up is to buy a kit specifically designed to work together Mixing and matching components is inefficient and not effective

Hub Motor Specifications 0-20 mph in at least seconds 500w or greater power hub motor 36v motor (higher voltage requires less amperage which means less heat) Fits a 135mm rear dropout Disc brake compatible Cruise control preferred Brake cutoff switch to protect motor Battery rack

Current Electric Kit Selections Amped Bikes Golden Motor

Hub Motor Features Both are 36v, 500w motors which allows us to order from Golden Motor without the battery and use the one that comes with the Amped Bike kit Golden Motor kit has integrated cruise controller. Amped Bikes only has thumb throttle. Eventual goal is to electronically simulate the throttle signal, so the fact that the kit doesn’t have cruise control is acceptable mainly because the kit is FREE! Both are disc brake compatible Both fit 135 mm dropouts Both have brake cutoff switches which are important to prevent the motor from burning out from excess load caused by applying throttle while braking Both feature integrated controller and throttle

Original Gyro Mount Idea