Dirt jumping

From Wikipedia, the free encyclopedia

Dirt jumping is one of the names given to the practice of riding bikes over shaped mounds of dirt or soil and getting airborne. The idea is that after riding over the 'take off' the rider will become momentarily airborne, and aim to land on the 'landing'. Dirt jumping can be done on almost anything with wheels, but it20 inch wheels.

Mountain bikes - 24 or 26 inch wheels and either rigid forks or forks with short front end suspension (usually 80-100 mm travel, but can be up to 150mm+ depending on the type of the bicycle)
Freestyle Motocross (FMX, Moto-X) of various sizes & engine sizes.
bmx bike built for dirt jumping tends to have a longer top tube than a street BMX bike, and may well be more reinforced. They will rarely have pegs fitted (unless they are also used for street riding), and will generally run only a rear u-brake. Also, the tires will be treaded, as opposed to the slicks and semi-slicks used for park riding. Large, padded seats are also popular as something to land on when a trick fails, and are also easier to hold for in-flight tricks; but very small seats are also a style for the more "hardcore" riders. The gear ratio is generally around 44:16, though using small gearings like 22:8, known as 'micro gearing', has become popular in the present day.A photo of some BMX trails courtesy of barendbmx.co.uk

A mountain bike built for dirt jumping tends to has a smaller frame than what is used for other disciplines. Running singlespeed is very common, as is using only a rear brake. In modern times, using single or dual disc brakes has replaced the use of only one rear V-brake. In general, a mountain bike dedicated to dirt jumping will have 24" or 26" wheels, a gear ratio of 1:2 (32:16, 36:18 and 24:12 being its most popular incarnations) and rigid or 80-100mm travel forks. An 'all-round' bike used for dirt jumping will more likely have 26" wheels, a 30-36 teeth chainring with a wide-ratio cassette and a short- to mid-travel fork. Mountain bike dirt jumpers are usually split on the basis of wheel size because the wheel size dictates the shape of the takeoff to an extent. Dirt Jump bikes are mostly made by Kona who make several different models like the Kona Shred and Kona Scrap Another group of popular dirt Jumping bikes is the Specialized P-series. Such as the P all mountain, P grom, P1, P2, P cromo(steel frame), and the P3.

1 History
2 Types of jumps
3 Tricks commonly performed
4 Notable Riders
5 External links

[edit] History

Dirt Jumping evolved alongside bmx racing from its birth. Dirt Jumping is similar to BMX or Mountain bike racing in that the rider jumps off of mounds of dirt. It differs in that the jumps are usually much larger and designed to lift the rider higher into the air. Additionally, the goal is not to complete the course with the fastest time, but rather to perform the best tricks with the best style. Trails are most often hand built, with attention to detail.

[edit] Types of jumps

Double the most common form of Dirt humps. This consists of two separate earthworks, one acting as a takeoff(lip), and the other as a landing. Also known as a "gap" jump. They can be "Step-Ups", where the jump's upramp is lower than the down ramp or "Step-Downs", where the jump's downramp is lower than the upramp. Tabletops are more common among those new to the sport, they are a single earthwork with a takeoff at one end, and a landing at the other, with a flat 'table' on the top. These are favoured by new riders because when the rider comes up short they can still easily ride out of it. Ski jumps consist of just a takeoff, they're usually longer and flatter than other jumps, and tend to be situated on downhills, so the slope of the hill can serve as a landing. They're used mostly in competitions on jump length. Roller a small tabletop that gives you extra speed by 'pumping' the jump. you usually find these at the beginning of a trail. Step ups a ramp just before an incline to enable a rider to jump from the top of the incline. Whoops/Rhythms a series of usually three or more small rounded ramps close together to enable a rider to 'manual' over them.

[edit] Tricks commonly performed

Name	Description
Tabletop(T-top)	While in the air tiping the bike on its side to a 90¨¬ angle or further.
Euro Table	sometimes called a Darkside, a euro table is when you turn your handlebars downwards instead of upwards as you would in a table.
Invert(Unturndown)	essentialy a table, but over extended for more style, possibly enough for the front tire or fork to rub on your shoulder.
Whip(Fish tail)	Keeping the front of your bike straight while flicking the back to one side. There are many different styles of whips, each depending on the style of the rider.
Cannonball	Taking both feet off the pedals while grabing the seat with both hands.
Tuck No hander	Both hands off the handlebars with your legs pinching top tube and your bars in your lap.
Suicide No hander	hands behind back while in the air with legs pinching seat.
Toboggan	One hand off handlebars touching the seat or top tube, one hand turning bars 90¨¬. Tilt front down for extra style.
No footer	Both feet off pedals.
Cancan	One foot taken off and put over top tube to the other side of bike
No-footed Cancan	Similar to Cancan except done on both sides so that both legs are together, off the pedals and on the same side of the top tube
Backflip	Rotating bike and rider completely upside down & continuting to rotate 360¨¬ of vertical rotation until facing original angle/direction
360	Rotating the bike and rider completely round 360¨¬ horizontally until facing original direction.
Front flip	Inverse of a back flip head tucked into handlebars and body in the fetus position
Heelclicker	Both feet come off the pedals, around the bars, and meet at the heels.
X-up	Turning the bars 180¨¬ or further without releasing the handle bars to make the riders arms form an X shape
Barspin	Releasing & spinning handlebars one full rotation before catching them again
Truckdriver	A 360¨¬ while doing a barspin
Tail Wip	Rotating bike 360¨¬ under rider remaining in standard position without releasing the handle bars
Turndown	Similar to an x-up but the entire body turns with the bars and the bike frame is as vertical as possible. Variation on the "cross-up" which incorporates elements of both the "Table" and X-up.
Superman	No footer with feet extended out to the back, in a Superman position.
Superman Seatgrab	A standard superman but with one hand on the seat rather than the handlebars
Nothing	Nothing is touching the bike, neither arms nor legs, hence the name.
3-Star	Only one hand touches the handlebars, so the extended arm and legs form a star.