Bicycle Brakes – Expert Article on Disc Brake Recalls

In this article, bicycle expert, Luke Elrath, discusses the 2013 voluntary recall of road bicycle brakes by the bicycle industry’s two largest component suppliers Shimano and SRAM.

Road Bicycle Brake Recalls

Three recalls in rapid succession from the largest bicycle brake suppliers in the world

The bicycle industry’s two largest component suppliers Shimano and SRAM have both announced voluntary recalls of road bicycle brakes in 2013. Mechanical disc brakes, hydraulic disc brakes and hydraulic caliper brakes are new developments in road bicycle technology; previously, nearly all road bicycles were equipped with cable actuated caliper rim brakes.

Shimano’s recall covered 6600 pairs of their cable-actuated mechanical disc brakes for road and cyclocross bikes. They could potentially fail causing a loss of braking ability. These items were sold aftermarket and also supplied as OEM equipment on BMC, Giant, Ibis, Raleigh, Shinola, Specialized and Volagi brand road and cyclocross bicycles.

SRAM recalled 3500 pairs of both hydraulic rim and disc brake models in November of this year. In December, SRAM announced that owners of all road and cyclocross bicycles equipped with their hydraulic disc or hydraulic caliper brakes should stop use immediately. In freezing temperatures a seal can fail leading to a total loss of braking power. Approximately 19,000 sets of brakes are affected by this action.

A total loss of braking power represents a very serious hazard. High performance road bicycles regularly reach speeds in excess of 45 mph on steep descents. Any compromise in the bicycle’s braking ability can lead to serious injury or death.

Disc brakes for the road are a new trend in the US bicycle industry. Both hydraulic (oil operated) and mechanical (cable operated) disc brakes have been in use on mountain bikes for many years. What is different about disc brakes for use on the road is the potential for higher speeds, longer descents and much greater temperatures.

Heat generated while braking a conventional road bicycle with caliper rim brakes can be dissipated over a much larger surface area (the wheel rim on a road bike has nearly three times the surface area than that of a standard road bike disc rotor).

As dictated by physics, energy equals mass times the square of the speed. Doubling the speed generates four times the energy. This energy must be converted to heat in order to maintain a safe speed or come to a controlled stop. Road bikes have shown for decades that a wheel rim is effective at dissipating the large amount of heat that can be encountered while braking from very high speeds. Mountain bikes designed for high speed downhill racing are equipped with huge 8 ¼” brake rotors to deal with the heat. Today’s new road bike disc brakes are only available up to 6 1/3” due to frame clearance limitations. Many feel that this is simply too small to cope with the heat generated by braking.

Competition within the bicycle industry to introduce new technology that is lighter, faster, and designed for higher performance means brands rush to be the first to market with any new innovation. The Consumer Product Safety Commission and the American Society for Testing and Materials create regulations for bicycle design and testing in the United States. When new innovations are introduced these bodies may not be able to evaluate the safety concerns and factors quick enough to identify the need for new standards and testing. New products hit the shelves, early adopters buy them to gain a competitive advantage, and occasionally failures in new products can cause severe injuries and death.

When a bicycle crash occurs, it is necessary to examine all factors regarding the design, manufacture, maintenance and operation of the bicycle to determine the cause of the incident.

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