Cycles of all sorts

Effective use of a bicycle brake is highly counter-intuitive. The casual rider will at first avoid using the front brake, due to the unsettling feeling of "toppling up", or fear of being sent flying over the handlebars.

However, the most effective technique for powerful stopping is to use the front brake almost exclusively. There are several exceptions where the rear brake is preferred; these are listed below. In any stop, the rider should shift their weight toward the rear and use their arms to brace against the deceleration.

During braking (either with the front or rear brake), the bike deceleration causes a transfer of weight to the front wheel. This means that there is more force pressing the front wheel to the ground, and the back wheel nearly none. Therefore, the front wheel can generate more frictional braking force than the back wheel before locking up and skidding. In any conditions and especially in wet conditions or going downhill, the rear brake can exert relatively little braking force before the wheel locks and starts skidding. For a more-detailed analysis, see Bicycle and motorcycle dynamics.

A skidding rear wheel can lead to dangerous, uncontrollable bicycle movements eventually resulting in the cyclist falling on the ground. A key scenario for this is "light" braking on rapid alpine-type hairpin (serpentine) descents; further attenuation of speed to negotiate a decrease in curve radius (tightening of the bend in the road) can be executed successfully while pulling through a tight corner regulating with the front brake only.

In an emergency stop, it is important to grab the front brake and press it hard to stop in the minimum possible distance. The rider should shift his or her weight as far to the rear as possible to avoid flipping over the handlebars. Maximum deceleration is accomplished by maintaining enough pressure on the front brake such that that the rear wheel is barely touching the ground, just before lifting up. In reality this is not practical for most cyclists. Instead, use light pressure on the back wheel and hard pressure on the front. The back wheel is primarily useful as an indicator—when it starts to skid, reduce the pressure to both brakes to prevent the rear wheel from lifting, then increase pressure to both again.

Incidentally, on tandems, and long-wheel-base recumbents with their long wheelbase and center of mass farther from the front wheel, it is virtually impossible for heavy front braking to cause the machine to flip.

There are a few special situations where limited use of the front brake, and heavier involvement of the rear brake is advisable:

• Slippery surfaces: It is difficult to recover from a front-wheel skid on a slippery surface, especially when leaned over, so on surfaces when skidding is likely (e.g. wet pavement, mud, snow, or ice), reduced speed and use of the rear brake may be preferred.
• Bumpy surfaces: If the front wheel comes off of the ground during braking, it will stop completely. Landing on a stopped front wheel with the brakes still applied is likely to cause the front wheel to skid and, possibly, for the rider to flip over the front bars.
• Flat front tire: Braking the front wheel when the tire is flat could cause the tire to come off of the rim, which is more likely to cause a crash.