1) The vast majority of braking power comes from braking the front wheel. Applying backwards pressure to the pedals does nothing, which means a fixie's braking

1) The vast majority of braking power comes from braking the front wheel. Applying backwards pressure to the pedals does nothing, which means a fixie's braking power is considerably limited. 2) Additionally, the braking is much smoother and more easily regulated with real brakes. 3) Stiction is stronger than dynamic friction. If you brake the rear wheel just below the point at which the wheel skids on the ground, you're disapating more power than if you skid the rear wheel i.e. you'll stop faster not skidding than skidding. These reasons are why in many places (e.g. the UK) a front brake is legally mandatory. Edit: spelling