Science Fair Project Encyclopedia
A bicycle pedal provides the connection between the cyclist's foot or shoe and the crankarm allowing the leg to be used to turn the crank. The Velocipede, a predecessor to the bicycle, lacked pedals but allowed the crank to be operated by means of a treadle . Pedals were initially attached to crankarms connecting directly to the driven (usually front) wheel. The safety bicycle as we know it today came in to being when the pedals were attached to a crankarm driving a ring gear that was attached to the driven wheel by means of a chain.
Early pedals were simply platforms (with a rotating axis) on which the cyclist could press downward with the foot. Later, cages called toe clips were added to help keep the foot in place. Then toe straps were added to both further secure the foot to the pedal and to allow the cyclist to apply power on the upstroke by pulling against the pedal. The clip is generally made of metal or high impact plastic. The strap is generally made of leather or nylon.
In 1984, the French company LOOK, applied downhill snow skiing binding or cleat technology to pedals producing the first practical clipless pedals. Bernard Hinault's victory in Tour de France in 1985 helped secure the acceptance of quick-release clipless pedal systems by cyclists. Those pedals, and compatible models by other manufracturers, remain in widespread use today.
The term clipless refers to not using an external toe clip. Clipless pedals require a special cycling shoe with a cleat fitted to the sole, which interfaces with a locking mechanism on the pedal. Cycling shoes have inflexible soles to maximize power transfer and efficiency. They may either be specific to road or mountain biking or useable for both. Also, some have a protruding cleat, making them difficult to use for walking.
Various other manufacturers have produced their own design of clipless pedal systems over the years, most notably BeBop, LOOK, Speedplay, Time, and Shimano.
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