Shoes and Pedals

Think of yourself as a big battery! This battery feeds power into your bike every time you pedal. When pedaling using a standard pair of (flat) pedals, you only ever use 50% of your battery's energy. This is because you can only apply downward pressure with one leg at a time. Your other leg just spins around with no real input.

When using a pair of special SPD pedals and shoes, your feet are actually able to clip onto the pedals (much like a pair of ski boots) allowing you to pull up as well as push down. This effectively doubles your power input. The end result is 100% use of your battery's energy.