As one gear turns, the other gear must also turn. Where the gears meet, the teeth must both move in the same direction. In the diagram, the teeth of both gears move upwards. This means that the gears ...

Different gears like spur, bevel, worm and wormwheel, rack and pinion, meshed gears, and threaded bars serve various purposes. When selecting a gear system, consider speed, direction, force, space, ...

An internal gear hub provides multiple gears on a bicycle in an enclosed unit housed within the rear hub. Almost all bikes with gears now feature a derailleur system. But for a long time, internal ...