What equipment rules apply to a mountain bike in a race?
Officials' detail · The cross-country race · 1 of 2The mountain bike rules themselves are a short list of bans: no electric assistance, no radio link to the rider, no metal-spiked tyres, no road-style drop handlebars or clip-on extensions and no cameras in a final. Wheel size and suspension are left to the rider. The general rules for all bicycles are in another Part.
How it works
- E-bikes: riders may not use an electrically assisted bike on the course "at any time during training or competition", except at e-mountain bike events.
- Radio: "radio links or other remote means of communication with riders" are forbidden, except at World Cups with authorisation.
- Tyres: metal spikes or screws are not permitted, except in snow bike events.
- Handlebars: "no traditional road handlebars may be used". Clip-on extensions and inner bar ends are forbidden. Traditional bar ends are allowed.
- Cameras: not permitted in a cross-country final, or in the qualifying rounds and finals of downhill, four cross and eliminator.
- Timing device: where the timing company provides one, the rider must wear it.
- Handlebar number: the rider must finish with the plate they started with.
- Wheels: the general rule is two wheels of equal diameter. In downhill and enduro the two wheels may differ.
- Drive: in downhill the bike may be driven by a chain or a one-piece belt.
- Helmet: the general helmet rule is in Part 1. Downhill has its own, stricter rule.
The glossary has suspension, cross-country and downhill.
Tricky cases
Is there a required wheel size?
No. This Part sets none. It says only that in downhill and enduro the two wheels may be of different diameters.
Can a team talk to its rider by radio?
No. Radio links are forbidden, except at World Cups with the UCI's authorisation.
Can a rider film the race from the handlebars?
No, not in a cross-country final. The UCI may allow a camera there for the television production only.
Is suspension required?
No. The Part does not require it or limit it.
Why the rule exists
Mountain bike design moves quickly, and the rules mostly stay out of its way: they do not fix a wheel size, a frame shape or the amount of suspension. What they ban are things that would change the contest itself, such as a motor or a voice in the rider's ear.
Where it differs
| Where | What changes | Source |
|---|---|---|
| Downhill and enduro | Wheels of different diameters allowed | UCI 4.1.044 |
| Snow bike | Spiked tyres allowed, spikes up to 5 mm | UCI 4.1.039 |
| E-mountain bike events | Pedal-assist bikes, motor up to 250 watts, assistance up to 25 km/h | UCI 4.8.001 |
| Pump track | Flat pedals only, at least a rear brake, wheels of 20 inches or more | UCI 4.6.003 |
From the rule book
Union Cycliste Internationale, Cycling Regulations, Part 4: Mountain Bike Races (JCF edition 2025, amendments applying 1 January 2026), articles 4.1.038 to 4.1.044, 4.2.046, 4.6.003 and 4.8.001. Checked 14 October 2026. Official document: UCI Cycling Regulations, Part 4 (PDF).