Whether you have a standard electric bike or you’ve used an electric conversion kit on your existing bike, you may be wondering how fast can it go? Here in the UK, there is a limitation on the maximum speed your electric bike is allowed to go before its classed as a “motor vehicle”. The limitation in the UK comes in the form of having a maximum electric motor power output of 250W. Any electric bikes that have more power than 250W will need to be registered with the DLVA.
In terms of how fast an electric bike can go, in the UK, you can legally achieve speeds of up to 15.5 MPH using the assist mode with a 250W electric motor. However, you can go faster than this if you increase the speed at which you are pedalling once the electric motor reaches its maximum limit of 15.5 MPH.
Elsewhere in the world, you are able to go much faster and this can be up to 20 MPH in some cases. For example, in the US, the maximum power you are allowed to use on an electric bike is 750W and this will assist you up until 20 MPH.
What Happens If My Electric Bike Is Too Fast?
If you are riding an electric bike in the UK that exceeds 15.5 MPH or has a motor that’s more powerful than 250W, it’ll need to be registered, insured and taxed. On top of this, you’ll also need a valid driving license and have to wear a suitable motorcycle helmet too. If you want to find out more about registering an electric bike, you can do so on the UK GOV website, which goes through all the eligibility criteria along with the application process.

How Fast Do The More Powerful Electric Bikes Go?
If you intend to register the electric bike for use in the UK or want to use it off-road, you may wish to explore the larger power options. The most common power outputs include 250, 500, 750, 1000 and even 1500W.
In terms of the approximate top speed these electric motors can achieve on flat ground, they can be as fast as:
- 250W – 15 – 20 MPH
- 500W – 20 – 25 MPH
- 750W – 25 – 28 MPH
- 1,00W – 28 – 35 MPH
- 1,500W – 35 – 40 MPH
Although these electric motors can achieve fast speeds, they are often limited by the manufacturer in order to comply with the laws set by each country. For example, the 250W motor is limited to 15.5 MPH in the UK.
Why Is The Speed Limited On Electric Bikes
As you can imagine, the main reason why there is a speed limit on an electric bike is primarily for safety. Falling from your bike isn’t a pleasant experience and it’s made even worse when you fall off at speed.
To the annoyance of many cyclists, the limit in the UK is much lower than elsewhere in the world. However, there are many petitions that are asking the UK government to consider raising the speed inline with the US legislation (20 MPH).
Conclusion
Electric bikes are improving each year but the speed to which you can legally travel is likely to remain at 15.5 MPH in the UK. Although this may seem relatively slow in a car, it’s certainly fast enough on a bike. Of course, if you require more speed, you can do so by pedalling faster once the motor reaches is limit whilst in the assist mode.
Along with the speed restrictions in the UK, it’s important that you follow the other rules set out by the government. For example, your electric bike must also display its battery voltage or maximum speed as well as the manufacturer of the motor. You can find out more about the various electric bike rules in the UK upon the official website.

