Hub gear

part · 1902 · Electric age

Hidden gears inside the wheel hub (Sturmey-Archer).

Principles and materials it uses

Steel — is made of. The gears are steel.
Torque — uses. It changes the gear ratio inside the hub.

Where it is used

Bicycle wheel — is part of. Hubs with gears.

What it is a kind of

Planetary gear — is a kind of. A planetary gear.

Take Hub gear apart