gears & shifting

Gears help you keep good leverage (mechanical advantage) through a range of speeds as you cycle.

Shifters control the gears to change leverage as needed.

We usually see two kinds of gearing systems:

• derailleurs
• planetary gears

and two kinds of shifters

• twist grip - you operate these by twisting the grip as you hold it
• lever arms - you shift by pushing some paddle or arm (there are many permutations on the theme)