Bicycle brake systems

Early bicycles such as the high wheeled penny-farthing bikes had no brakes as we would recognise them. If the rider wanted to stop he (at that time there were no women riders) had to jump off the bike as it was moving. Unsurprisingly there were many accidents, many of them fatal, which limited the appeal of cycling to mostly young and adventurous men.

The 1870s saw the development of the "safety bicycle" which was roughly the bicycle we would recognise today, with two wheels of equal size, driven by a chain, with pneumatic tyres.

The braking system these bicycles used was often a simple leather pad which pressed against the top of the tyre, which was driven by a rod attached to a lever on the handlebar, and there was no rear brake. This was undoubtedly a big improvement on having no brakes at all, but was not very powerfull and had the big drawback that they were almost useless in wet weather.

After that the next big advance in bicycle braking, which came around the 1890s, was the invention of the rim brake. This is the type of brake most commonly used on bicycles today.

Rim brakes

Rim brakes, as has already been mentioned, are the most common type of bicycle brake in use today. Essentially they use two pads (usually made of leather or rubber) to press in scissor fashion against the side of the wheel rims, thus causing friction and slowing or stopping the bike; the power of the braking depends on how hard the pads push against the rims.

This force is applied by the rider squeezing a lever mounted on the handlebar, and transfered to the brake by means of a cable, or sometimes a rod. There are several different designs of rim brake, the most modern of which being the cantilever and V-brake designs which are very powerful. More traditional caliper brakes are still found on many road bikes.

The advantage of rim brakes is that they are cheap, lightweight, mechanically simple and easy to maintain. Also, modern designs of rim brake are very powerful.

One major disadvantage of rim brakes is that they need regular maintenance. Most notably the brake pads, friction causes the brake pads wear out and they have to be replaced at regular intervals. Also, if used over long periods of time the wheel rims also wear out due to friction, and have to be replaced.

The other main disadvantage of rim brakes is that their performance deteriorates in wet weather when the rims are wet, although this problem is far less serious on bikes which use rims made of Aluminium alloy. They are also prone to clogging with mud when mountain biking in wet conditions.

Disk brakes

This type of brake is most suitable for and found mainly on mountain bikes which are ridden off road.

Although this type of brake has been used on motorbikes for decades, only recently have they been added to bicycles. This type of brake works in a similar way to rim brakes, although is far more powerful and reliable. Basically a disk brake consists of a metal disk attached to the wheel axle between the spokes and the fork, there is a brake pad mounted near the bottom of the fork (the bit which the wheel is attached to), which presses against the disk when a cable is pulled by the rider, which stops the bike.

One advantage of this setup over a rim brake is that a far larger pad can be fitted, because on rim brakes the size of the pad is limited by the narrowness of the wheel rim. The large pads used on disk brakes are less affected by mud and water which means they will work well in all weather conditions. On some expensive disk brake models, a Hydraulic system is used to push the pad instead of a cable.

Another advantage of disk brakes is that they are very powerful and, as mentioned before, their performance is equally good in all conditions. They also avoid the problem that rim brakes have of wearing out the wheel rims. They are generally easier to maintain than rim brakes too.

On the down side, however, they are heavier and more expensive than rim brakes.

Hub brakes

Hub brakes are brakes that have their mechanism enclosed within the hub of the wheel, and are usually fitted to the back wheel. They are drum brakes[?] which are the type of brake used on cars. Because they are enclosed, hub brakes are completely unaffected by the weather Some types of hub brake are operated by cables and levers, in the same way as rim and disk brakes. Other types are operated by the rider turning the pedals backwards, these are known as "back pedalling brakes", or "coaster brakes" in U.S English.

In addition to being impervious to changes in the weather, hub breaks have the advantage of needing very little regular maintenance, especially the back pedalling type.

On the downside, when hub brakes do require maintenance it is far more complicated than other braking systems. They occasionaly need to be dismantled and re-greased, usually by a professional. Also hub brakes are heavier than all the other types of bicycle brake.

Hub brakes are used mainly on utility bikes[?]

See Also Adjusting brakes