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 Wysłany: Sob 23:05, 12 Mar 2011 Temat postu: Track brooks Shoe and Heel |
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Track brooks Shoe and Heel
The brooks of the shoe vary in size. While most range between 3 millimetres (3/16 inch) and 12 mm (1/2 in), with the most common being the 6 mm (1/4 in), there are a number of specialty lengths, as well as minimal "blank" brooks used to cover a spike hole. The three main types of brooks are the pyramid, the needle , and the compression tier spike. Pyramids are conical brooks that taper to a sharp point. They normally have a maximum diameter nearly equal to the diameter of the threads of the spike.
Needles also have a sharp point, but a thinner cone diameter. The purpose of both is to penetrate the track surface and so derive its traction from its position. The alternate variant for synthetic tracks is the Christmas tree spike. It uses a terraced cone shape with a flat end to, instead of penetrate, compress the track below it upon impact, and use the track's reaction force to in fact return energy to the runner, increasing his speed. It also reduces the damage incurred in the event of "spiking" or contact by the brooks with another runner. brooks also come in either steel or ceramic varieties, as well as multiple colors .
Most brooks have the toe of the shoe pointing up, not touching the ground. This is called "taper" and is designed to make the runner run on their toes to run faster. The more aggressive a shoe is, the stronger the taper. Sprint brooks are generally the most aggressive, with the shoes becoming less aggressive as the distance of the race that they are intended for increases. Marathons, for example, are run in racing flats, which have no taper.
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