Brake systems are employed to slow down or stop a bicycle that is in motion. There are several different devises and methods to do so but most use friction on some portion of the wheel to slow rotation. Stopping power of a bicycle is an important aspect of riding safety.
How it works
There are several types of brake systems each with their own unique features. Due to the multiple methods, certain systems are better adept to different riding styles and practices. Here is a list of the most popular and widely used brake systems.
Spoon Brakes: The first brake system developed for slowing down a bicycle, spoon brakes are the simpliest design consisting of a single lever. Spoon brakes are applied directly to the wheel using a pad to create friction and slow the rotation of the wheel.
Disc Brakes: This brake system employs an additional thin disc to the hub of the wheel. Brake pads are applied to the sides of the disc rather than the wheel directly. This minimizes wear on the wheel tread from braking. Another advantage is the quicker stopping time and smoother stop from the thin disc located closer to the hub than rim brakes. Disc brakes are used on performance bikes as the same design is used for high performance vehicles as well.
Drum Brakes: These brakes are mounted in a contained drum around the wheel hub. When activated, a friction brake pad on the inside presses the interior of the drum, which turns with the wheel, to slow the bicycle down. The enclosure keeps the brake system shielded from the elements. Drum brakes are also used for heavier bikes, such as tandem bikes, to help with the added force when stopping.
Rim Brakes: Most widely used for general bicycle riding, rim brakes apply pressure to the rim of the tire using a thick brake pad. There are several designs of this type including center-pull and side-pull cable brakes that have a cantilever for pressure.
With the exception of the simple spoon brake, most all of these brake systems are activated by brake cables mounted on the handle bars. The tension of the brake line dictates the force of the brake pads on either the disc, the rim or the drum. Still in development and very expensive are anti-lock brake systems for bicycles.
References: Description of Disc and Drum Brakes: (http://tandem-fahren.de/Mailingliste/Mitglieder/Christoph_Timm/DiskFAQ.html) Rim Brakes: (http://thebicycleplanet.com/page.cfm?PageID=242)
Evolution of the brakes
The beginning development of the bicycle did not include a brake system. The early "hobby horses" were propelled by the user's legs and also stopped by the user's legs. Even later models with pedal cranks did not have adequate brakes requiring the rider to jump off in order to stop. The ensuing accidents and injuries harmed the bicycle market for many years. The first mention of stopping device was with the "Safety Bicycle" during the 1870s. This simple spoon brake was added which applies direct force to the wheel. Sometimes in the form of a paddle, spoon brakes greatly improved the safety and control of early bicycles. Once gear and chain systems were added to the bicycle, a rider could back pedal to stop the forward rotation of the wheels. It is sometimes refered to as fixed gear braking. This method of stopping is still employed on children's bicycles for its simplicity. Rim brakes moved the friction applied to the tire down to the rim once that style of tire was more widely used. More high tech brakes have been developed for specialized purposes. Disc brakes were invented to improve the stopping power of larger and heavier bikes. Drum brakes were also developed for use in rugged areas to prevent wear and tear from the elements. Many of the new developments in brake technology are being adapted from automobile applications.
References: http://www.kleinbikes.com/us/support/om/om/klein_road/brakes.html http://www.pedalinghistory.com/PHhistory.html http://www.fonant.co.uk/windcheetah/ http://tandem-fahren.de/Mailingliste/Mitglieder/Christoph_Timm/ http://www.sheldonbrown.com
CAD Files:Top Arm; Nut1; Nut2; Spacer; Brake Pad; Thumb Bolt; Cable Bolt;
convert: missing an image filename `/tmp/transform_6f2724354a4b-1.jpg' @ error/convert.c/ConvertImageCommand/3011.