Dirt jump bicycles, also known as DJ bikes, are specialized mountain bikes designed for dirt jumping, street riding, and park riding. These bikes are built to handle the rigors of jumping and performing tricks, featuring a robust and minimalist design.

1. Frame: Typically made from aluminum or chromoly steel, with a lower top tube for more clearance and better control during jumps and tricks.

2. Suspension: Usually hardtail (no rear suspension) with a short-travel front suspension fork (around 80-100mm) to absorb the impact from jumps.

3. Geometry: Designed with a shorter wheelbase, steeper head tube angle, and lower standover height, providing greater maneuverability and control.

4. Wheels: Usually equipped with 26-inch wheels, though some models may use smaller wheels like 24 inches for even more agility.

5. Single Speed: Most dirt jump bikes are single-speed to reduce weight and mechanical complexity, though some may have gears for versatility.

6. Durability: Strong, durable components, including thick tires, strong rims, and reinforced hubs, to withstand the heavy impacts of dirt jumping.

7. Brakes: Often equipped with a rear disc brake for reliable stopping power, though some riders may prefer hydraulic or mechanical disc brakes for more precision.

• Dirt Jumping: Riding on dirt tracks with large jumps, performing tricks mid-air.
• Street Riding: Performing tricks and maneuvers on urban terrain.
• Pump Tracks: Riding on a looped track with bumps and berms, using body movements to maintain momentum without pedaling.
• Skate Parks: Riding on ramps, bowls, and other skate park features.

Dirt jump bikes are popular among riders who enjoy the thrill of jumping, trick riding, and tackling technical urban or dirt features. They’re designed for maximum control, durability, and fun.