MTB Bikes

Q: How is a Dirt Bike constructed?

Frame Compact and stable with short chainstays for easy manuals. Mostly Hardtail (front suspension only). Fork Special Dirt forks (e.g., RST Dirt, Manitou Circus, RockShox Pike DJ) with 80mm to 100mm travel. They are tuned harder than trail forks so they don't absorb energy during take-offs. Wheels Almost always 26 Inch. They offer the perfect compromise between stability and rollover behavior. Drivetrain Mostly Singlespeed with a robust chain (often halflink), similar to BMX. This saves weight and is low maintenance. Often uses 3-piece CrMo cranks. Brake Usually only a hydraulic disc brake in the rear with a long hose for barspins. Some street bikes use mechanical disc brakes for gyro systems.

Q: What materials are used?

Aluminum (6061-T6) Light and stiff. The first choice for Dirt Jump contests, pumptracks, and racing (e.g., Radio Griffin). Power transfer is extremely direct. Chromoly Steel (4130 CrMo) The classic from BMX. Slightly heavier, but extremely durable and with slight natural damping. Popular with Street & Park riders (e.g., Radio Asura).

Q: How do I assemble my new Dirt Bike?

Unboxing: Carefully remove the packaging material. Front Wheel: Insert the front wheel into the fork (tighten QR or thru-axle). Handlebar: Mount the bar to the stem and tighten bolts evenly in a cross pattern. Pedals: Mind the left and right threads! Grease the threads and tighten firmly. Check: Check tire pressure (3.0 - 4.0 Bar is common for Dirt) and the brake.

MTB Bikes FAQ

How is a Dirt Bike constructed?

Frame: Compact and stable with short chainstays for easy manuals. Mostly Hardtail (front suspension only).
Fork: Special Dirt forks (e.g., RST Dirt, Manitou Circus, RockShox Pike DJ) with 80mm to 100mm travel. They are tuned harder than trail forks so they don't absorb energy during take-offs.
Wheels: Almost always 26 Inch. They offer the perfect compromise between stability and rollover behavior.
Drivetrain: Mostly Singlespeed with a robust chain (often halflink), similar to BMX. This saves weight and is low maintenance. Often uses 3-piece CrMo cranks.
Brake: Usually only a hydraulic disc brake in the rear with a long hose for barspins. Some street bikes use mechanical disc brakes for gyro systems.

What materials are used?

Aluminum (6061-T6): Light and stiff. The first choice for Dirt Jump contests, pumptracks, and racing (e.g., Radio Griffin). Power transfer is extremely direct.
Chromoly Steel (4130 CrMo): The classic from BMX. Slightly heavier, but extremely durable and with slight natural damping. Popular with Street & Park riders (e.g., Radio Asura).

What do the specifications mean? (Dirt Jump specific)

Here we explain the specs using a typical dirt bike (e.g., Radio Asura):

Term	Explanation	Typical Values
Top Tube (TT)	Length of the front frame section. Determines how much room you have for tricks.	22.5" to 23" (Inches)
Chain Stay (CS)	Distance from BB to rear axle. The shorter, the easier the bike manuals/spins.	15" - 15.5" (Very short!)
Head Angle (HA)	Steering angle. Dirt bikes are steeper than enduros for direct steering.	69° - 70°
Drivetrain / Cranks	Often 3-piece CrMo cranks (BMX standard) with small gearing.	25T/28T/30T front, 10T-13T rear
Travel	Fork suspension travel. Stiff setup for jumps.	100mm (Standard)

How do I assemble my new Dirt Bike?

Unboxing: Carefully remove the packaging material.
Front Wheel: Insert the front wheel into the fork (tighten QR or thru-axle).
Handlebar: Mount the bar to the stem and tighten bolts evenly in a cross pattern.
Pedals: Mind the left and right threads! Grease the threads and tighten firmly.
Check: Check tire pressure (3.0 - 4.0 Bar is common for Dirt) and the brake.