Understanding E-Bike Throttles: What’s Legal and What’s Not

If you're diving into the world of electric bikes, you'll likely come across discussions about throttles - particularly around their legalities. The use of throttles on e-bikes is regulated, but the laws can be tricky to navigate. Here’s a breakdown to help you understand what’s allowed and what isn’t when it comes to e-bike throttles in the UK. Make sure to read the full article, as the answer isn't as clear cut as you might imagine!

Want to check out our collection of throttle powered electric bikes? Explore our dedicated page here.

The Basics of Throttle Regulations

Contrary to popular belief, throttles on electric bikes aren’t outright banned in the UK. However, their use is subject to specific legal conditions. For an e-bike to be considered road-legal:

1. The walk-assist functionality must not propel the bike beyond 3.7mph (6kph) without pedalling.
2. The motor must cut out once the bike reaches 15.5mph (25kph).

This means that while you can propel yourself without pedalling to give yourself a small boost, it's not allowed to replace pedalling entirely once you’re moving faster than 3.7mph.

Walk assist functionality and full throttles are sometimes confused. Walk assitance (anything limited to 3.7mph) will only propel the bike if you are not sat on the bike due to the power restriction manufacturers need to apply. This is for two reasons:

• Ride Quality – Allowing full torque below 3.7mph would make the throttle feel harsh and jerky, more like an on/off switch than smooth acceleration.
• Legal Compliance – UK law requires throttles to cut at low speed. If the throttle delivered full torque, the wheel could spin far beyond the 3.7 mph limit during a compliance test, making the bike appear non-compliant and therefore illegal.

In short, "throttles" that propel the bike but then cut out at 3.7mph are a restricted walk mode (compliant with UK reglations) and should not be confused with a full throttle.

The Evolution of UK E-Bike Law

Before 1st January 2016, the UK's e-bike regulations were more relaxed than those in the European Union. In fact, "Twist and Go" throttles, which could power an e-bike up to 15mph without any pedalling, were completely legal. However, with the harmonisation of UK law with EU standards, this changed.

From 2016 onwards, e-bikes must follow the “Walk Start” rule. This allows riders to travel up to 3.7mph without pedalling, but beyond that, pedal assistance is mandatory. Once the bike exceeds 3.7mph, the assist cuts out, and the motor only assists if you're pedalling. This helps to ensure that e-bikes remain bicycles rather than being classified as motorised vehicles.

Different Interpretations Across Europe

Interestingly, not all countries interpreted the new rules the same way. Brands selling in the UK and EU have adapted to the legislation differently. For example, in some cases, e-bikes are programmed so that the throttle can continue to assist up to 15mph as long as you’re turning the pedals. If you stop pedalling, the motor will cut out, and the throttle will only allow you to coast at 3.7mph - unless you’re riding downhill and freewheeling.

The Line Between E-Bikes and Mopeds

Once an e-bike can propel the bike over 3.7mph without pedalling, it’s no longer considered an e-bike but a “Low Powered Moped.” These mopeds require type approval from VOSA (Vehicle and Operator Services Agency) and must meet additional specifications, such as having integrated lights and mudguards.

How Throttles Vary Between E-Bike Models

Not all e-bike throttles work in the same way. On some models, the throttle’s power is limited to the level of pedal assist you've selected. For instance, if you’re riding with power assist limited to 10mph, the throttle won’t push you past that speed. However, other e-bikes override pedal assist levels when the throttle is engaged, allowing full power acceleration up to the legal limit of 15.5mph.

The Wisper Exception

There is a way to buy an e-bike with a full throttle! Wisper offer fully UK-legal full-throttle eBikes that can reach speeds of 15.5mph without pedalling.

When you order a Wisper full-throttle eBike, it will be tested by the DVSA and approved as an L1e category 250W Low Powered Moped. This approval process, which takes 2-8 weeks, involves inspection at an approved MVSA centre. Once tested, you receive a British National Type Approval certificate valid for the bike's lifetime, with no need for renewal.

While using the throttle, the bike operates like a standard eBike without affecting its EAPC features. To comply with Type Approval, the bikes must have front and rear lights controlled by a single switch. Currently, the Tailwind Trail, Tailwind City, and Wayfarer Mountain models cannot be approved due to the absence of lights, but solutions are in development.

Once approved, these bikes can be legally ridden on UK roads and private land using just the throttle.

The Benefits of Throttles on E-Bikes

While throttles can't do all the work for you, they offer significant advantages, especially when you need a brief rest. Riders can use the throttle to maintain speed with less effort, though it’s important to remember that even powerful 48V e-bikes will still require you to pedal on hills and use the gears to assist the motor effectively.

Whether you're new to e-bikes or an experienced rider, understanding throttle regulations and how they function on different models is crucial for ensuring you stay within the law - and get the most out of your e-bike experience.

Looking to get a throttle powered electric bike? Explore our collection here.

Further Reading

For full requirements and the most up-to-date information, please consult official government sources which we have provided for you below:

• https://www.gov.uk/government/publications/electrically-assisted-pedal-cycles-eapcs/electrically-assisted-pedal-cycles-eapcs-in-great-britain-information-sheet
• https://www.gov.uk/electric-bike-rules

Disclaimer: The information provided in this article is for general guidance only and does not constitute legal advice. Laws can change over time. It is the responsibility of the customer to ensure that their electric bike complies with all current UK laws, including EAPC regulations. For the most up-to-date legal requirements, please refer to official government sources.