Bicycle brake

The coaster brake was contained in the rear wheel hub, and was engaged and controlled by backpedaling, thus eliminating the issue of tyre wear.

[7] Spoon brakes were used on penny farthings with solid rubber tyres in the 1800s and continued to be used after the introduction of the pneumatic-tyred safety bicycle.

The spoon brake consists of a pad (often leather) or metal shoe (possibly rubber faced), which is pressed onto the top of the front tyre.

The low price and ease of maintenance of rim brakes makes them popular in low- to mid-price commuter bikes, where the disadvantages are alleviated by the unchallenging conditions.

[13] In normal use this is not a problem, as the brakes are applied with limited force and for a short time, so the heat quickly dissipates to the surrounding air.

For wet-weather use, brake pads containing iron (iii) oxide are sometimes used as these have higher friction on a wet aluminum rim than the usual rubber.

It is common to see professional racers climbing mountains with the quick-release undone on the rear brake, to eliminate drag from this source.

This is especially valuable on freestyle BMX bikes where any protruding parts are susceptible to damage and may interfere with the rider's body or clothing.

Due to a wider possible distance between the mounts and pads, cantilever brakes are often preferred for bicycles that use wide tyres, such as on mountain bikes.

Originally, cantilever brakes had nearly horizontal arms and were designed for maximum clearance on touring or cyclo-cross bicycles.

Some high-end v-brakes use a four-pivot parallel motion so the brake pads contact at virtually the same position on the wheel rim regardless of wear.

V-brakes function well with the suspension systems found on many mountain bikes because they do not require a separate cable stop on the frame or fork.

Poorly designed V-brakes can suffer from a sudden failure when the noodle end pulls through the metal stirrup, leaving the wheel with no braking power.

On the downside, their shorter arms provide very small tyre and wheel clearance and generally make for a less forgiving setup: they can only accommodate smaller tyre sizes compared to cantilever brakes, may pose problems for mounting fenders, can be clogged more easily by mud, and they can make it harder to change wheels.

They also require maintenance: like U-brakes, as the pad wears it strikes the rim higher; unless re-adjusted it can eventually contact the tyre's sidewall.

However, Bicycle Quarterly criticized the delta brake for being heavy, giving mediocre stopping power, and suffering disadvantageous variable mechanical advantage.

Bending the rotor is theoretically inferior, but in practice gives good service, even under high-force braking with a hot disc, and may yield more progressiveness.

In 2014 Shimano introduced a "Flat Mount" standard for high end road bikes and uses it exclusively for its top tier brake calipers.

Larger rotors provide greater braking torque for a given pad pressure, by virtue of a longer moment arm for the caliper to act on.

Some models contain a torque-limiting device called a power modulator designed to make it difficult to skid the wheel.

These use special extra-short derailleurs which can stand up to the forces of being straightened out frequently and do not require an excessive amount of reverse pedal rotation before the brake engages.

As of 2011, the Arai drum brake has been out of production for several years, with remaining stocks nearing depletion and used units commanding premium prices on internet auction sites.

DT-Swiss make an adapter to mate disc rotors with hubs threaded for the Arai drum brake, but this still leaves the problem of fitting the caliper.

Using the incorrect fluid type will cause the seals to fail resulting in a "squishy" feeling in the lever, and the caliper pistons are unable to retract, so a scraping disc is common.

Some older designs, like the AMP and Mountain Cycles brakes, use a cable from lever to caliper, then use a master cylinder integrated into the piston.

Some Santana tandem bicycles used a cable from lever to a master cylinder mounted near the head tube, with a hydraulic line to the rear wheel caliper.

This solution is often seen on modified Long John cargo bikes, allowing a low friction lever pull front wheel brake action.

After Sachs ceased production of this kit a similar solution is sometimes done by welding on a Magura piston to the drum cylinder lever.

If the front brake is used too hard, momentum may cause the rider and bike to pitch forward – a type of crash sometimes called an "endo".

[citation needed] The usual method of stopping is for the rider to put one or both feet on the ground, or to wedge a foot between the seat and the rear tyre, effectively acting as a spoon brake.