What’s the maximum power of an electric bike?

Legal restrictions for riding electric bikes on the road

Electric bikes are becoming very popular. The first models looked painfully uncool, but now there are bikes that look very fashionable. Given that an electric motor can be both small and very powerful – enough power to propel a pedal cycle well above the urban speed limit – are there any restrictions on what you can ride on the road legally?

A muscle-powered push bike (i.e. one powered by a person) has a finite amount of power, restricted by human endurance and strength. An elite cyclist can produce about 5 watts of power for every kilogram of body weight over the course of an hour. Therefore a 60kg elite cyclist can produce 300W for one hour. Elite cyclists peak at around 500W (0.5kW) for short bursts and this allows them to propel their bikes at up to 80kph on flat roads for short periods, i.e. a sprint to the finish line. A track cyclist can produce around 700W for a short time, as you can see in the video at the end.

The New Zealand government has set the maximum for a road-going electric-powered bicycle with pedals, with the primary means of propulsion being the human riding it, at 300W. It’s called a power-assisted cycle and is a class AB vehicle.

While you can purchase electric bikes with power in the kilowatts, these are considered to be mopeds between 300-2000W (if they are allowed to be registered at all, because you must have front and rear lights, a horn, rear view mirrors, indicators and a maximum speed of 50kph). With 300W the top speeds will be between 20-30kph without pedal assistance on a flat road.

Cycle riders must adhere to the Road Code – you can check out the bicycle rider’s Road Code here.

If you want a bike with more than 300W, companies such as Stealth will sell you a 4.5kW bike which will top 80kph, but you can only use it off-road.

Yike Bikes

A Yike Bike is a small electric bike with a large front wheel and a small back wheel. There are no pedals and it just functions as an electric method of transportation.

There are slightly different rules for Yike Bikes. You must wear an approved cycle helmet. You can ride it on the road, but you must remain as close to the left-hand edge of the roadway where possible.

If you ride it on the footpath you must give way to pedestrians and mobility devices and not cause a danger to them by riding too fast.