Mountain bike components- pedals

Standard ( also known as 'traditional' or 'regular') pedals are a straightforward platform or cage onto which you can usually bolt on toe-clips and fit toe-straps. Toe-clips and straps keep your foot in the correct position on the pedal and, if the strap is tightened, you can pull the pedal up on the back stroke as well as pushing down on the down stroke - making your pedalling much more efficient.

However, in the mid-1990s, the ubiquity of the humble toe-clip and strap was challenged by French manufacturer Look, who came up with a clipless pedal system that engaged directly with a cleat on the sole of the shoe - rather like a ski-binding (Look's core business). A spring-loaded mechanism secures the cleat to hold the shoe and pedal together and a twisting action releases the foot - allowing the foot to release in case of an accident.
Immediately the off road riders saw the advantage of the clipless pedal system. Toe clips and straps were cheap and simple but they could be cumbersome and difficult to engage, leaving them prone to catching on the ground, awkward to tighten and if tightened, slow to release. The first 'clipless' pedals were designed for road use but these were impractical for off road use as they involved a large cleat, proud of the shoe sole and for weight savings and aerodynamics, were single sided only. Shimano came to the rescue with their 'SPD' (Shimano Pedalling Dynamics), a smaller pedal, double sided for off-road use. The main difference was that the cleat was recessed into the sole such that it was still very easy to run and walk in the shoes. Other manufacturers have emulated Shimano's design but essentially they retain the same principles. SPDs (as they are universally known - whatever the make!) have also been adopted by tourists and commuters who appreciate the convenience of being able to walk comfortably as well having good foot security when cycling.

Most clipless pedals allow the foot some 'float' so that it can assume a natural twist during the pedalling action. However, it is imperative that the cleat is positioned correctly, firstly to position it under the ball of the foot and secondly to get the angle of the foot correct. If not, efficiency will be lost, but more seriously knee damage could occur. Note that you left and right feet may need to have the cleats positioned slightly differently. As with any product, more money buys a better quality product (at least, up to a point) using better quality, more durable material and bearings. The Shimano range of pedals is extensive and offers good value for money. Taiwanese manufacturers, VP and Wellgo also have some very acceptable pedals at budget prices and US-designed Ritchey pedals are highly regarded. Some models have appeared using elastomers in place of a mechanical spring mechanism, but the majority of pedals still use a spring to secure the cleat on the pedal.

For trials riding, most riders prefer regular, flat pedals, used in conjunction with flat, rubber-soled shoes. Down hill and dual riders are divided between clipless and flat pedals. To cater for these and some leisure riders, for them there are broader, double sided clipless pedals, and some 'combination' pedals with a clipless mechanism on one side of the pedal, and regular flat platform on the other side.