Dirt jumping is one of the names given to the practice of riding bikes over cement type jumps of dirt or soil and becoming 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 it is usually executed on a dirt jump bike.

• BMX
  BMX
  Bicycle motocross or BMX refers to the sport in which the main goal is extreme racing on bicycles in motocross style on tracks with inline start and expressive obstacles, and it is also the term that refers to the bicycle itself that is designed for dirt and motocross cycling.- History :BMX started...
  
   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 or unles the person wants to exicute a peg grab), 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 25:9, known as 'micro gearing', has become popular in the present day.A photo of some BMX trails courtesy of barendbmx.co.uk
• Hybrid BMX/Jump bike - a scaled up BMX with 24" wheels. Strong alloy rims and lightweight chromoly frame. Suited to bigger jumps or more challenging competition courses.
• Freestyle Motocross
  Freestyle Motocross
  Freestyle Motocross is a variation on the sport of motocross in which motorcycle riders attempt to impress judges with jumps and stunts.The two main types of freestyle events are:...
  
   (FMX, Moto-X) of various sizes & engine sizes.

* Dirt Jump/Freestyle mountain bikes look similar to mountain bikes but have a rigid frame and, a lower stand-over height, this keeps the seat out of the way while performing tricks. The wheels are usually more robust than a cross country

Cross-country cycling

Cross-country cycling is the most common discipline of mountain biking. While less publicized than downhill cycling as it is more difficult to televise, it garners the highest levels of participation both recreationally and competitively....

 mountain bikes and the same for the frame. Frames are built for a balance of strength and lightweight.

• Mountain bike
  Mountain bike
  A mountain bike or mountain bicycle is a bicycle created for off-road cycling. This activity includes traversing of rocks and washouts, and steep declines,...
  
  s - 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 203 mm depending on the type of the bicycle) Firm suspension is desirable for dirt jumping.

A mountain bike built for dirt jumping tends to have 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 approximately 60 gear inches (~36:15 on a 24" rear wheel or ~36:16 on a 26" rear wheel) and rigid or 80-100mm travel forks. An 'all-round' bike used for dirt jumping will more likely have 26" wheels, a 25-36 tooth 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 made by a variety of companies. Examples of commonly purchased bikes for the general purpose of dirt jumping include the Kona Shonky or Cowan, (Kona also have a line of trail oriented bikes that are also suited for dirt jumping, the Shred and Stuff) Specialized

Specialized Bicycle Components

Specialized Bicycle Components, more commonly known simply as Specialized, is a major American brand of bicycles and related products. It was founded in 1974 by Mike Sinyard and is based in Morgan Hill, California-History:...

 P.1, P.2, P.3, Norco

Norco Performance Bikes

Norco Bikes is a bicycle manufacturer founded in 1964 and currently headquartered in Port Coquitlam, British Columbia, Canada. Norco designs and distributes more than 140 bike models to more than 21 countries.-History:...

 125, 250, Havoc or Ryde, Transition's Trail-or-Park, Bank or Double, Giant Brass or STP, Devinci

Cycles Devinci

Cycles Devinci is a Canadian bicycle manufacturer established in Chicoutimi, Quebec in 1987. In addition to a full line of road, mountain and hybrid bicycles, it also manufactures the Bixi bicycle used in bicycle sharing schemes in cities such as Montreal and Toronto. Devinci supplies a similar...

 District, Haro Thread and Porter, Blk Mrkt Mob, Riot, Contraband, Killswitch, Soldier or Malice, NS Majesty, Suburban or Capital, Dobermann Pinscher or Molosse, Trek Ticket Signature, the Banshee Amp or Rampant, and khs awesome line up of dirt jumpers the dj and sj series.

a 20 inch BMX bike for dirt generally has a 48 spoke rear rim and a 36 spoke front to prevent rim collapse in the case of casing a jump. the frame is a little bit longer to aid in more stability and to spread the load of heavy lands. most of these "micro geared" bike run 85 to 100 psi tires. these are usually threaded and made with kevlar bead to prevent pressure flats and tears.

History

Dirt Jumping evolved alongside BMX racing from its birth. Dirt Jumping is similar to BMX

BMX racing

BMX racing is a type of off-road bicycle racing. The format of BMX was derived from motocross racing. BMX bicycle races are sprint races on purpose-built off-road single-lap race tracks. The track usually small a starting gate for up to eight racers, a groomed, serpentine, dirt race course made of...

 or Mountain Bike racing

Mountain bike racing

The Union Cycliste Internationale recognised the sport of mountain bike racing relatively late in 1990, when it sanctioned the world championships in Purgatory, Colorado. The first mountain biking world cup series took place in 1991. Its nine-race circuit covered two continents—Europe and North...

 in that the rider jumps off of mounds of dirt

Dirt

Dirt is unclean matter, especially when in contact with a person's clothes, skin or possessions when they are said to become dirty. Common types of dirt include:* dust — a general powder of organic or mineral matter...

. 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.
Dirt jumping has evolved a lot over the years now, there are now competitions that you can compete in for prizes. The dirt jumps have become much larger and better built. They now use diggers and other machines to help build and compact the dirt quicker and more efficiently. The dirt jumps which are sometimes even built with wood can even be up to between 20 and 30 feet long for the professionals. The tricks have evolved a lot partly due to freestyle motocross evolving where a lot of the dirt jumpers get their inspiration from. When it first started it would be just tabletops and whips as the main tricks, now nearly every professional can back flip, front flip and even double back flip.

Types of jumps

• Double the most common form of Dirt jumps. 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 and the rider loses speed, or "Step-Downs", where the jump's downramp is lower than the upramp, meaning that they gain speed.
• 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.
• Rollers are small tabletops that give you extra speed by 'pumping' the jump. You usually would find these at the beginning of a trail.
• Step ups are ramps just before inclines to enable rider to jump from the top of the incline.
• Whoops/Rhythms a series of three or more small rounded ramps close together to enable rider to 'manual' over them.
• Spine is one earth work with a take-off and a landing, but no table or gap, made to get higher air without distance.
• Berm basically is a curved wallride that comes out of the ground. Mostly used on sharp turns in which helps you by giving you the ability to ride on your side. The curve allows you to make a sharper turn. Mainly used on downhill trails but, also used dirt jumping to avoid hitting trees. They are also used to maintain your speed without having to brake on turns. Some trails consist of jumps that lead into berms.
• Hip Jumps consist of the landing being anywhere within 0 - 90 degrees, left or right of the take off enabling you to transfer.

Name	Description
Tire grab	while airing, the rider grabs his/hers front tire
Tabletop	While in the air tipping the bike on its side to a 90° angle or further.
Euro Table	sometimes called a Dark side, a euro table is when you turn your handlebars downwards instead of upwards as you would in a table.
Invert	essentially a table, but over extended. possibly enough for the front tire or fork to rub on your shoulder.
Unturndown	Similar to an Invert, but the riders legs remain straight and the seat tend to wrap around the riders outside leg.
Whip	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 and grabbing 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.
One foot can	One foot taken off and put over top tube to the other side of bike
No-footed Can-can	Similar to one foot can except done on both sides so that both legs are together, off the pedals and on the same side of the top tube
Nac-Nac	Similar to the One foot can, except your leg goes behind your other one still on the pedal, instead of in front.
Backflip	Rotating bike and rider completely upside down & continuing to rotate 360° of vertical rotation until facing original angle/direction. Can also be performed twice (while still in the air) to make a double back flip.
360	Rotating the bike and rider completely round 360° horizontally until facing original direction.
Front flip	Inverse of a back flip
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
Tail Whip	kicking the bike while holding the handlebars so that it makes a 360 degree rotation while the rider does not rotate
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.
Superflip	Superman while backflipping.
3-Star	Only one hand touches the handlebars, so the extended arm and legs form a star.
Dangler	Only one foot on one pedal with both hands taken off the bars, a variation of the "3-star"
Backflip Tailwhip (Flipwhip)	As the name suggests, doing a tailwhip whilst upside down (halfway through) a backflip.
Flair	More commonly a bmx trick, this can be also be done on a mountain bike. It involves getting substantial air off a vert ramp, then doing a backflip and 180 so that you roll down the ramp going back the way you came.
Truck Driver	Doing a 360 and barspin combination, when the bars spin in the opposite direction of the 360.
Decade	Like a barspin, but person wraps around with the bars in a 360° position while tail stays straight.
Orbital 360	Like a regular 360, but the rider dips the front of the bike down so that both the rider and the bike are vertical during the rotation, the end of the rotation generally feels and looks a bit like a backflip.
California Roll	Invented by Mike Montgomery, this is where the rider does a 360 around his bike, it is similar to a body varial however the rider does not touch the bike during the rotation.
Cliff Hanger Backflip	Invented by Mike Montgomery, this is where the rider does a no hander but holds on the handlebars with their feet, while in a rotation of a backflip.
Flip Double whip	Invented by Greg Watts, this is where the rider does a back flip and two tail whips whilst in the air .
Truck Driver Tailwhip	Invented by Martin Soderstrom, this is where the rider does a Truck Driver and a tailwhip, which is when the rider does a 360 barspin to tailwhip.
360 Downside Tailwhip	Invented by Tyler Mccaul, this is where the rider does a 360 and a tailwhip in the opposite direction.
Special Flip	Invented by "Special" Greg Powell from Nitro Circus Nitro Circus Nitro Circus is an American television series that featured Travis Pastrana and his friends traveling around the world riding dirtbikes, base jumping, and performing reckless stunts. It was originally run as a miniseries in 2006 on Fuel TV. In January 2009, it began running as an episodic reality... . This is where the rider performs a backflip while the bike stays flat.