How to use this model
  1. Press Pedal (hold it to keep going), or drag the crank round with your finger.
  2. Choose a chainring (34 or 50 teeth) and a rear sprocket. Watch the derailleur move the chain.
  3. Read the numbers: teeth ÷ teeth gives the gear ratio, the number of wheel turns for one pedal turn.
  4. Press Coast and stop pedaling: the wheel keeps turning and the freehub clicks.
  5. Tap any part, or use ◀ ▶, to zoom in and read about it. Look inside slides the cassette off to show the pawls.
Chainring
Rear sprocket18
Teeth50 ÷ 18 Gear ratio2.78 Per pedal turn5.83 m At 60 rpm21.0 km/h

23 parts
Roller chain, 12.7 mm (½ inch) from pin to pinChainrings 34 and 50 teeth; cassette 11 to 32 teethGear ratio = chainring teeth ÷ sprocket teeth = turns of the wheel for one turn of the pedals. Each wheel turn rolls the bicycle 2.1 m (a 700 × 25c tire), so meters per pedal turn = ratio × 2.1. The drawing pedals at a quarter of real speed; the speed shown is for 60 pedal turns a minute. Bigger rear sprocket: easier to push, but slower.