Electric Bikes

Electric bikes are growing quickly in popularity, with riders enjoying the extra assistance provided by the motor for everything from city riding and commuting by bike, to weekend road rides and trail-centre trips.

However, electric bikes are subject to different laws and regulations compared to non-assisted bikes.

What is the legal definition of an electric bike?

Most electric bikes in the UK fall within the ‘electrically assisted pedal cycle’ (EAPC) category. 

An EAPC must:

• Have pedals that can be used to propel it.
• Show either the power output or the manufacturer of the motor.
• Show either the battery’s voltage or the maximum speed of the bike.
• Have an electric motor with a maximum power output of 250 watts.
• Not have a motor able to propel the bike when it’s travelling at more than 15.5mph.

An EAPC must have a motor with a maximum power output of no more than 250 watts. It also requires pedals to propel it. 

An EAPC’s motor can only provide assistance when the rider is pedalling. It will have sensors built into the system that recognise when the rider is pushing on the pedals and provide power from the motor in proportion to this, so the bike doesn’t run away with you or power you along without pedalling.

By law, assistance from the motor must cut out at 15.5mph (25km/h) – that’s the same across the UK, EU and Australia (but, this limit rises to 20mph in the USA).

You can ride an ebike faster than this, but the motor will cut out and you’ll then be riding solely under your own steam. It’s perfectly possible to exceed 15.5mph when travelling downhill, while a fitter rider will be able to exceed this speed on the flat, particularly on a performance-oriented, drop-bar electric road bike.

Note that there’s a newer category of cargo-carrying ebikes that can be fitted with a more powerful motor, up to 1,000 watts. This L1e-A classification requires the rider to be licensed, and the bike needs to be registered and insured. Power output can be regulated by a throttle on L1e-A bikes.
However, the vast majority of electric bikes sold in the UK fall under the EAPC classification.

What are the regulations when riding an ebike?

An EAPC is treated like a regular, non-assisted bike in the UK.

If an ebike falls within the EAPC definition, legally it is treated like a regular, non-assisted bike, although you do have to be at least 14 years old to be allowed to ride an electric bike.

You don’t need to register the bike and you don’t need to have insurance. You are also not legally required to wear a helmet.

You can ride an ebike anywhere you are permitted to ride a regular bike. That includes on roads, cycle lanes and bridle paths. As with a non-electric bicycle, you’re not allowed to ride on pavements, unless they’re designated for mixed cycle and pedestrian use. You have to obey the Highway Code too, including stop signs and traffic lights.

If you’re not confident that you know the rules when riding, it’s worthwhile enrolling in a cycle safety class and getting to grips with the Highway Code.

Watts and torque

While electric bike motors are limited to a continuous peak output of 250 watts, how that power is delivered (i.e. the torque) can differ from one system to another. Motors designed for off-road riding typically offer more torque, and are better-suited to steep, loose climbs. 

An ebike motor’s output isn’t measured only in watts – its torque output and assistance levels are also important factors in its performance.

Torque is the amount of turning power that the motor delivers to the wheels, determining how fast the ebike will accelerate and how steep a gradient it can tackle. An ebike’s torque output isn’t governed by legislation.

Most ebike systems will feature a display to show key data such as the motor’s power setting and battery life, though more advanced units may include GPS, too. 

Torque figures vary significantly between electric bike motors, depending on what the system is designed for.

Flat-bar electric hybrid bikes and drop-bar road ebikes typically have torque outputs of between 40Nm and 60Nm. For example, Bosch’s Active Line motor has a maximum torque of 40Nm and is designed for urban riding.

Electric mountain bikes are usually heavier and need to be able to tackle steep, loose off-road climbs. As a result, they will often have much greater torque outputs, starting at around 60Nm and, in the case of Bosch’s Performance Line CX motor, topping out at 85Nm.

What laws apply to non-compliant electric bikes?

There are a couple of types of electrically powered bikes that don’t fall within the legal definition of an EAPC.

Speed Pedelecs

These are electric bikes where you have to pedal but the motor’s output is more than 250 watts and assistance isn’t speed limited at 25km/h. 

An example is the range of electric bikes made by Swiss brand Stromer. Its ebike motors have power outputs of between 670 watts and 850 watts, which in turn can power its machines up to 45km/h.

Twist-and-go

These are models where motor input is controlled by a twist grip on the handlebar, so you don’t need to pedal to keep the bike moving. These twist-and-go ‘accelerators’ are different from the controllers often found on the handlebars of compliant EAPCs, which let you choose between assistance levels.

In the case of both Speed Pedelecs and twist-and-go bikes, these machines are treated by UK law like petrol-powered mopeds. That means:-

• they must be taxed and insured.
• you must have a licence.
• you need to wear a motorcycle-style helmet to ride them.
• Like mopeds, they can only be ridden on roads or unrestricted byways.