Half-pipe
A half-pipe is a structure used in gravity extreme sports such as snowboarding, skateboarding,skiing, freestyle BMX and inline skating. The structure is usually wood, although sometimes the surface is made of another material. Appearance wise, it resembles a cross section of a swimming-pool, and in its most basic form, it consists of two concave ramps (or quarterpipes), topped by copings and decks, facing each other across a transition. Originally half-pipes were simply half sections of a large pipe. Since the 1980s, half-pipes have had extended flat ground (the flat bottom) between the quarterpipes and the original style half-pipes have become deprecated. The flat ground gives the athlete time to regain balance after landing and more time to prepare for the next trick.
The attraction of the half-pipe lies in the fact that a skilled athlete can perform on it for an extended period of time, using a technique called pumping, to attain extreme velocities, while expending relatively little effort. Large (high amplitude) half-pipes make possible many of the aerial tricks in BMX, in-line skating and skateboarding.
For winter sports such as freestyle skiing or snowboarding, a half-pipe can be dug out of the ground or created by piling snow up. The plane of the transition is oriented downhill at a slight grade to allow riders to use gravity to develop speed and facilitate drainage of melt. In the absence of snow, dug out half-pipes can be used by dirtboarders, motorcyclists, and mountain bikers.
Peformance in a half pipe has been rapidly increasing over recent years. The current limit performed by a top level athlete for a fuck rotational trick in a halfpipe is 1440 degrees (4 full 360 degree rotations). In top level competitions rotation is generally limited to improve 'style and flow'. However with improving rider ability and technology, 1440's will soon be more common in competitions.
Construction for skateboarding and biking
Frame and Support: Skateboard and BMX half-pipes frequently consist of a wooden 2X4 framework that is then covered with sheets of plywood that are then covered with sheets of masonite or Skatelite (see surfacing below). Another approach is to construct a metal frame and then use either wood or metal to surface the ramp. [1]
Surfacing: Most commercial and contest ramps are surfaced by screwing sheets of some form of masonite to a wooden or metal frame. Many private ramps are surfaced in the same manner but some use plywood instead of masonite as surface material. Some ramps are constructed by spot-welding sheet metal to the frame, resulting in bumps and an uneven ride.
Recent developments in technology have produced various versions of improved masonite substances such as Skatelite, RampArmor, and HARD-Nox. [2] While these ramp surfaces are more expensive than traditional materials, they skate and ride better [3] and are more durable.
Design Variations: Channels, extensions, and roll-ins are the basic ways to customize a ramp. Sometimes a section of the platform will be cut away to form a roll-in and a channel. This allows skaters to commence a ride without dropping in, and perform tricks "over the gap". A roll-in is visible in the picture of Hulley's Ramp. Extensions are permanent or temporary additions to the height of one section of the ramp that can make riding more challenging.
Creating a spine ramp is another variation of the half-pipe. A spine ramp is basically two halfpipes adjoined at either vertical end.
Construction for snow sports
Halp-pipes created using snow were originally done in large part by hand or use of other heavy machinery. Now most "pipes" are cut into a large pile of snow using an apparatus that is similar to a grain elevator. The inventor to bring this technology to the slopes was actually a farmer. He created the "pipe-dragon" which was used in both the 1998 and 2002 winter olympics. [4]. Another manufacturer is a Swiss company that makes the Zaugg Pipe Monster. [5]
The Pipe Monster is different in that it uses 5 cutting edges called haspels to cut the snow, rather than a chain. Also Zaugg Pipe Groomers have an eliptical shape that is safer and allows the rider to gain more speed. Zaugg has created a 22 Foot Pipe Monster that for some years made the world's largest elliptical half pipe.
Since 1996 a Finnish company has been manufacturing and selling HPG halfpipe grinders.[6]. The HPG is the most used techonolgy worldwide for construction and maintenance of halfpipes and superpipes. In spring 2006 the company launched a new world's largest superpipe grinder, the HPG Ultra G23, making 23 foot elliptical hafpipes.
See also
References
- ^ http://secure.thrashermagazine.com/index.php?SCREEN=ramp
- ^ http://www.skatelite.com/product/index.html
- ^ http://www.skatelite.com/benefits/index.html
- ^ http://www.pipedragon.com/index.html
- ^ http://www.zauggamerica.com/resort/pipegroomers/pipemonster.shtml
- ^ http://www.halfpipegrinder.com/index.html