| A half-pipe is a structure used in gravity extreme | | | | to allow riders to use gravity to develop speed |
| sports such as snowboarding, skateboarding, | | | | and facilitate drainage of melt. In the absence of |
| skiing, freestyle BMX and inline skating. The | | | | snow, dug out half-pipes can be used by |
| structure is usually wood, although sometimes the | | | | dirtboarders, motorcyclists, and mountain bikers. |
| surface is made of another material. In | | | | The attraction of the half-pipe lies in the fact that |
| appearance, it resembles a cross section of a | | | | a skilled athlete can perform on it for an |
| swimming-pool, and in its most basic form, it | | | | extended period of time, using a technique called |
| consists of two concave ramps (or quarterpipes), | | | | pumping, to attain extreme speeds, while |
| topped by copings and decks, facing each other | | | | expending relatively little effort. Large (high |
| across a transition. Originally half-pipes were simply | | | | amplitude) half-pipes make possible many of the |
| half sections of a large pipe. Since the 1980s, | | | | aerial tricks in BMX, in-line skating and |
| half-pipes have had extended flat ground (the flat | | | | skateboarding. |
| bottom) between the quarterpipes and the original | | | | Performance in halfpipe has been rapidly increasing |
| style half-pipes have become deprecated. The flat | | | | over recent years. The current limit performed |
| ground gives the athlete time to regain balance | | | | by a top level athlete for a rotational trick in a |
| after landing and more time to prepare for the | | | | halfpipe is 1440 degrees (4 full 360 degree |
| next trick. | | | | rotations). In top level competitions rotation is |
| For winter sports such as freestyle skiing or | | | | generally limited to improve 'style and flow'. |
| snowboarding, a half-pipe can be dug out of the | | | | However with improving rider ability and |
| ground or created by piling snow up. The plane of | | | | technology, 1440's will soon be more common in |
| the transition is oriented downhill at a slight grade | | | | competitions. |