Shifting Gears - Efficient Riding you may ride a 24 speed that means you have 24 different gear combinations. You shift according to how your body feels. The purpose of shifting is to keep your pedaling at a steady pace, called cadence which is the number of times one foot goes around in a minute. You should shift gears every time you feel your legs starting to strain or spin quickly. This most often happens as terrain changes, as you begin to climb a hill you may need to shift to an easy gear.