eBike category: rules and guidance

1. Why we're running an eBike category

The eBike category is an entry point into mountain bike racing. Many riders have only ever ridden an eBike and have never had the chance to race. This category gives them a local, friendly, safe place to start.

This is not an electric motorbike race, and it is not about who has the most powerful bike. Every bike in the category meets the same legal standard, so results come down to the rider: fitness, skill, line choice and racecraft.

Our aim is simple: a level playing field, safe racing and fair results for everyone.

Category structure (first season)

• One class, called "E-bike". There are no ability categories, and everyone races together.
• Results are given for Open and Female.
• Minimum age: 16. The same rule as the other adult categories: riders must be 16 or older, counted on 1 January of the season.
• Race length: 1 hour plus a lap, for both the Open and the Female race.

2. What counts as an eBike

For MTB east, an eBike is a mountain bike that meets the UK legal definition of an Electrically Assisted Pedal Cycle (EAPC). In plain terms:

A note on "peak power"

Many modern eMTB motors advertise big figures, such as 600W, 1000W or even 1500W "peak" power and 85–150 Nm of torque. These bikes are still legal if they are rated at 250W continuous and cut out at 25 km/h. The law limits continuous rated power and assisted speed, not peak power. A powerful legal bike is welcome. A modified bike is not.

3. What's allowed

• Any eMTB with a factory-standard, UK-legal drive system (e.g. Bosch, Shimano, SRAM, DJI Avinox, Yamaha, Brose, TQ, Fazua, Specialized).
• All factory assist modes, including Boost / Turbo modes (see section 5).
• Adjusting assist settings through the manufacturer's official app, within factory limits.
• Range extenders supplied by the bike or motor manufacturer.
• Factory walk-assist mode (max 6 km/h) when dismounted and pushing.
• Normal upgrades that don't affect the motor or speed sensor, such as tyres, suspension, brakes, wheels and contact points.

4. What's NOT allowed

• Tuning devices ("chips", "dongles", "speed boxes") of any kind, fitted or carried.
• Modified or third-party firmware/software that changes assist speed or power.
• Region changes, e.g. a bike set to a 32 km/h US speed limit instead of 25 km/h.
• Tampering with the speed sensor, such as moving or removing the wheel magnet or fitting a fake sensor.
• Incorrect wheel-size settings entered to fool the speed sensor.
• Throttles, other than factory walk assist.
• Motors rated above 250W continuous, including "off-road only" or "private land use" eBikes.
• Hub-motor conversion kits and home-built eBikes, unless they are fully EAPC-compliant and labelled.
• Swapping batteries during a race. You finish on the battery you start with.
• Using walk assist while riding.

5. The Boost rule

Most modern eMTBs have a high-power mode, called "Boost", "Turbo", "eMTB" or "Auto" depending on the brand.

Boost and other factory modes are allowed. They are part of the legal, standard bike, and they still cut out at 25 km/h like every other mode. Using Boost is a riding choice, just like choosing a gear. It drains the battery faster, so managing it is part of racing.

What is not allowed is anything that makes a mode exceed the legal limits, such as assistance above 25 km/h or a throttle effect. If Boost is used through an unofficial app, hack or device, it's treated as tuning (section 4).

6. What's expected of riders

• Be 16 or older (counted on 1 January of the season, like every other category).
• Ride a legal, unmodified bike and be ready to have it checked at any time during the event.
• Sign the eBike declaration at sign-on confirming your bike is legal and unmodified.
• Present your bike for scrutineering before your first race of the day.
• Make sure your battery is charged before your race. No battery swaps during a race.
• Ride with respect. eBikes are typically 22–25 kg, much heavier than a standard trail bike, so:
  • call your passes clearly ("rider" / "on your left/right") and pass only where it's safe.
  • don't use motor power to force a pass on a narrow section.
  • give way to marshals, first aid and slower riders where safe.
• Practise safely. Practice sessions may be shared with other categories. Ride at a speed that lets you stop for anyone ahead of you.
• Use the protest process, not confrontation. If you're concerned about another bike, tell a race official (see section 9).
• Standard MTB east kit rules apply: helmet, gloves and any other kit required for your race format.

7. Keeping everyone safe on track

To address concerns about eBikes mixing with standard bikes:

• eBikes race in their own category and are not competing against standard bikes for results.
• eBikes start together with the Elite and S1 riders. The Female E-bike race starts with Female Elite and S1, and the Open E-bike race starts with Open Elite and S1. The start times are on the race day timings on the League page.
• You will sometimes share the course with younger riders on standard bikes. On the female side, for example, the U14, U16 and Fun races start at 10:45 while the 10:30 race is still on the course. So:
  • pass with extra care and give younger riders plenty of room.
  • call your pass early and clearly, and wait for a safe place to overtake.
  • never use motor power to squeeze past on a narrow section or climb.
  • remember that a 22–25 kg eBike hurts far more in a collision than a light youth bike.
• Race officials may give warnings, time penalties or disqualification for dangerous riding, unsafe overtaking or ignoring marshals. This applies to every category, eBikes included.

8. Scrutineering: what officials check

At sign-on, each eBike will have a quick check:

1. Motor label. Is there a label or marking showing 250W continuous rating and the manufacturer? Is the drive system a recognised brand?
2. No throttle. Is there no throttle on the bars, other than a factory walk-assist button?
3. Speed sensor. Is the wheel magnet and sensor present, in the standard position and undamaged? Are there any extra boxes, wiring or cable ties near the sensor or motor?
4. Display or app settings. Is the region set correctly, the maximum assist speed set at 25 km/h and the wheel size correct for the bike?
5. Cut-off test. With the rear wheel lifted, spin it up in the highest mode. The motor should stop assisting at about 25 km/h. A display that reads oddly low, or a motor that keeps driving, is a red flag.

Spot checks may also take place after racing, especially on podium finishers. Where possible, these may include a manufacturer diagnostic tool check.

9. What riders and spectators can look out for

What's normal on a legal eBike

• Very fast climbing. This is normal and expected. Most climbs are ridden below 25 km/h, so a legal bike gives full assistance all the way up, and a fit rider on a powerful legal bike can climb remarkably fast.
• Fast descending. Descending speed is gravity, not the motor, and is not a sign of an illegal bike.
• Motor noise on climbs, quiet on fast flat sections. On flat sections above 25 km/h, the motor should have cut out.

What might suggest an illegal bike

• Holding well above 25 km/h on flat or gently rising ground while pedalling, and pulling away from strong riders where the motor should have cut out.
• Motor still clearly driving at high speed on the flat.
• A throttle on the bars, or the bike moving without the rider pedalling.
• Extra boxes, wires or tape around the motor or rear wheel sensor.
• A display showing a speed that looks much lower than the bike's actual speed.

If you're concerned

Don't confront the rider. Tell a race official or the race day manager, with the rider's number. Officials will check the bike discreetly. Protests must be made before results are confirmed for that race.

10. Penalties and our learning period

This is a new category, and we're all learning together. We want to encourage riders, not catch them out.

Learning period: the whole of the first season (2027)

If a bike doesn't meet the rules during the learning period:

• We'll explain the issue and help the rider understand what needs changing.
• The rider cannot race on that bike in that condition. If the issue can be fixed on the day, for example by removing a dongle, resetting the region or correcting the wheel size, the bike can be re-checked and the rider can race.
• No further penalty applies for honest mistakes, such as a bike bought second-hand that has been modified without the rider knowing.

From the second season

• A bike that fails scrutineering cannot race until it's fixed and re-checked.
• A rider found racing on a tuned, modified or non-compliant bike will be disqualified from that race.
• Deliberate cheating, repeat offences or hiding a tuning device may lead to disqualification from the event and loss of series points.

The first season, 2027, is the learning period. These full penalties apply from the second season.

11. The spirit of the category

These rules exist so that everyone, whether a first-time racer, someone returning to the sport, or a rider who's only ever known eBikes, can line up knowing the race is fair.

It's not who has the fastest bike. It's who rides it best.

Questions about whether your bike is eligible? Get in touch before race day and we'll happily help you check: info@mtbeast.co.uk.