Bicycle drivetrain.

What does a bicycle gear change trade?

Setting up the mechanism…

Road speed: 8.80m/s
Drive force: 21.43N

Wheel turns per crank: 4.00

Fit the components, then test the mechanism.

What does a bicycle gear change trade?

The closed chain makes the rear wheel turn by the chainring-to-sprocket tooth ratio. A higher gear travels farther each pedal turn but delivers less rear-wheel torque for the same pedal torque.

v = 2πr cadence N_front/(60 N_rear)

What this model simplifies

Straight, lossless chain; no slip. Road speed is kinematic, not a terrain or drag simulation.

Read the source · ocw.mit.edu ↗

Put it to work.

Reach 4 m/s with at least 40 N drive force.

Make it work.

Find a gear ratio that balances speed and force.

Run

Fine adjustments 5

Chainring teeth

Sprocket teeth

Pedal cadencerpm

Wheel radiusm

Pedal torqueN·m

Bicycle drivetrain.

What does a bicycle gear change trade?

Loading the experiment…

Figuvo

Understand by doing.

Understanding is something you do.

Figuvo is a place to look inside everyday things, build a connection, and discover the idea behind them.

177 interactive experiments. Each has a working model and a challenge to test what you found.

The original inspiration

Levers & fulcrums The surprising gyroscope The field cannon Inside the human body

Original demonstrations by The Bugged Dev. The teaching models and interactions here are new implementations.

Community builds

New teaching models inspired by public builds shared around Anatomy.

Anatomy · the original announcement How a rocket pushes through space · Gustavo Inside a tactile key switch · @retaqib Pressure through the coffee bed · Gustavo The overbalance wheel · Shawn A seconds pendulum clock · @Baconbrix Three feet on the ground · Soju Inside a layered particle detector · Yash A double-deck pressure cabin · Charlie Leave the spent booster behind · @quantapar Principal, interest and escrow · Sean Gear a Martian year · @samani_Two balls in, two balls out · @samani_Two slits, one probability pattern · @samani_Join through a clear plastic cover · Josh Brown Lay pipe without a sharp bend · @Phi10w Eight cylinders and a blower · @love4hxns Four columns under a Joglo roof · Nur Asyrof An office for dependent tasks · Yaroslav Yablonski One image, six editable layers · Meng To The Redis caching machine · @uviii_03 Inside the Sony CMD-J5 · Ann Afterburner thrust stand · Joshua Guo Open-back headphones · Surajan Shrestha Two-thread lockstitch machine · @slashui Signal factory · Dhruval Golakiya

Bicycles and motorcycles

Bicycle drivetrain.

What does a bicycle gear change trade?

Setting up the mechanism…

Road speed: 8.80m/s
Drive force: 21.43N

Wheel turns per crank: 4.00

Fit the components, then test the mechanism.

What does a bicycle gear change trade?

The closed chain makes the rear wheel turn by the chainring-to-sprocket tooth ratio. A higher gear travels farther each pedal turn but delivers less rear-wheel torque for the same pedal torque.

v = 2πr cadence N_front/(60 N_rear)

What this model simplifies

Straight, lossless chain; no slip. Road speed is kinematic, not a terrain or drag simulation.

Read the source · ocw.mit.edu ↗

Put it to work.

Reach 4 m/s with at least 40 N drive force.

Make it work.

Find a gear ratio that balances speed and force.

Run

Fine adjustments 5

Chainring teeth

Sprocket teeth

Pedal cadencerpm

Wheel radiusm

Pedal torqueN·m