Bikes

Electric Bike Throttle: How Do They Work (and Are They Legal)?

Photo of throttle on electric bike.

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The Short Answer

Electric bike throttles allow riders to move forward without pedaling by twisting the throttle on the handlebars. Throttles come in different types, but their use is not always legal, so it’s important to check local laws.

E-bikes are more frequently seen on our roads and trails than ever before. Part of their appeal is the flexibility in how you get from A to B. You can pedal further for longer, or rely on the electric motor to support your pedalling. 

Power usually comes via pedal assistance, or by the use of a throttle. Pedal assistance is perhaps better known to most e-bike newcomers; so here we’ll take a look at the throttle system and what it’s good for. 

What Does an E-Bike Throttle Do?

An e-bike throttle is almost the same as that on an electric scooter or motorcycle. It’s found on the handlebars. By turning the throttle from a standing position, the bike will move forward without the rider needing to pedal. This can be especially useful when you need to start your bicycle on a hill.

a throttle can move an e-bike forward without pedalling

Can You Ride an Electric Bike without Pedalling?

When you open the throttle of an e-bike, the motor delivers power without the need for pedalling. Examples include stationary road users pulling away from traffic lights. With quiet stealth, the cyclist on an e-bike can take off with no human effort apart from twisting the throttle.

Even though pedalling is not required, the pedals must be capable of being used and in good working order. Some e-bikes with pedal assistance also use a throttle.

What Speed Does an Electric Bike Throttle Do?

A throttle could technically enable you to legally reach speeds up to 28 miles per hour on public roads without pedalling, where throttles are permitted. However, this varies from model-to-model, with most electric bikes topping out at around 10mph when using only the throttle.

Do All Electric Bikes Have Throttles?

Throttles on electric bikes are not standard. In fact, they are not legal in some regions and countries. Where they are not legal, you will see more of the pedal assistance bikes, which operate the motor when your feet turn the cranks. Different countries and states see throttle use differently.

types of throttle

Types of Electric Bike Throttles

Electric bike throttles can give you the twist and go sensation like riding a motorbike but there are other types which provide the same function. We’ll look at some of these below.

Half-Twist Throttles

No, the half does not refer to only twisting half-way. The half-twist throttle only takes up half the space on your handlebars normally reserved for your grips. Don’t worry, you should still get the grips with the bike. 

Half-grips usually operate with a twist of the wrist and control comes from the thumb and the first two fingers. Half-twist throttles help deal with the fatigue of extended use and also reduce the risk of accidental operation.

Thumb Throttle

Reducing things down to a small lever which pops out from the handlebar in the direction of the rider. Thumb throttles don’t get in the way of any of the other mechanisms on the handlebar. They operate by pressing the thumb. 

They carry the least risk of accidental operation. They rely on pressure from the thumb to control the spring loading of the lever which means the chances of fatigue to that digit are really the only concern.

Trigger Throttle

The trigger throttle takes the thumb throttle principle on a couple of notches. Again, it’s operated with a small lever on the handlebars, but you squeeze towards you with the fingers rather than pressing with the thumbs. 

pros of throttle

Do You Really Need a Throttle on an E-Bike?

Throttles can help in many situations which come down to choice and what you consider necessary. Sometimes we just don’t feel like pedalling – whether uphill or not. And some consider the ability to move away from a standing start quicker than you could under pedal power alone as an advantage.

There could be occasions where the pedal assist function alone is not enough to get you up really steep hills – a throttle could be a helpful assistant in these circumstances. Be wary that prolonged use of the throttle will affect the charge cycle of the battery.

Can You Add a Throttle to Any E-Bike?

If your e-bike comes with a working controller and a hub-mounted motor, in theory you could add a throttle to it. The controller unit will need to be able to accept a throttle. It will be complicated to add a throttle to a mid-drive motor because it relies on pedalling to spring into life. 

You’ll need to think about complications such as the available space on the handlebars, the extra wiring, is the motor fit to work under the duress of providing power from a standing start, and of course, will your e-bike fall out of warranty if you add a throttle.

cons of throttle

Can You Have a Throttle on an Electric Bike (Is It Legal)?

Legislation around e-bikes can be confusing at the best of times. Maximum speeds and speedometers plus maximum power output of the motor fall within the law and you can add throttles to the list too. You should check your own laws and not rely on any seller information alone.

We will focus on the use of a throttle on public roads. Use of throttles on private land is not always subject to the same laws. We will also assume that all other aspects of the bike are legal – lights, brakes, battery plate etc. 

Most throttle use in legislation is related to safety, speed and motor output power. You immediately enter motor vehicle territory once the bikes power and maximum unassisted speeds increase – limiting or prohibiting use on public roads and shared paths.

Electric Bike Throttle Law UK

Throttles in the UK as we have understood them for this post are not permitted without being classified as a motor bike. This means registration, number plates, tax and compulsory insurance and all users wearing a helmet. 

All e-bikes – or Electrically Assisted Pedal Cycles (EAPC) must have pedals that work, a maximum continuous rated power of the electric motor not exceeding 250 Watts and a cut off when the bike reaches 15.5 miles per hour. This does tend to limit the legal boundaries of a throttle to some extent anyway – especially the top speed as we have seen that throttle powered e-bikes are capable of at least 33% more than that.

Of course, there are e-bikes available with more powerful motors than 250 Watts and speed assistance limited to above 15.5mph. These are categorised as speed pedelecs and subject to the same mandatory motorbike classification requirements.

‘Twist and Go’ type bikes that meet the GB standards for e-bikes are permitted. You can only have one on a bike bought in 2016 or later and if it assists the rider without pedalling only up to a maximum speed of 3.7 miles per hour.  If the rider is pedalling at the same time, the throttle can assist up to 15.5mph.  They are designed for those riders who have difficulty starting due to injury or disability. And all manufacturers must be approved by the government. 

throttles on e-bike in the uk are not permitted to go above 3.7mph without pedalling

Electric Bike Throttle Law Europe

Although specific laws differ from state to state, the essence of throttle use on public roads is the same. The classification of an EAPC is the same as is the general classification of speed pedelecs. So, you’ll be riding a moped or motorised vehicle and all the hoops must be jumped through to ride legally.

Electric Bike Throttle Law USA

The federal legal definitions of an electric bike are broader in the USA. The pedals must be operable, the top speed for pedal assistance is limited to 20 miles per hour. 

They also refer to a maximum power output of 750 Watts, rather than a continuous power output. State jurisdiction exists for using e-bikes on state roads. 

Many states operate a three-tier system of rules and regulations which incorporate use of a throttle. Class I allows for a throttle but only to be engaged when a rider is pedalling. 

Class II incorporates those throttle powered bikes which require no human assistance, again, limited to 20mph.

Class III moves you into the same territory as speed pedelecs in the UK and Europe. The throttle can take you to unassisted speeds up to 28mph and can be allowed on roads and on-road bike lanes.

Each state has the ultimate say on whether you can ride a Class III bike legally on their roads or not. Some states even say that a Class II bike is a motorised vehicle. You should check the law before you invest in a throttle for your e-bike.

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