Electric Bikes

Can You Convert a Bicycle to Electric? (EXPLAINED)

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The Short Answer

Yes, most bicycles can be converted to electric by adding a motor and battery. Conversion kits are available, either as a hub motor for the wheel or a bottom bracket system. Consider legal requirements, compatibility, and warranty implications before converting your bike.

Most bicycles can be converted to electric. A battery and wheel, or bottom bracket modified with a motor is usually all that’s needed. 

Riding a bike with electric power can benefit the environment and also help you with weight loss. We look at the overall benefits of owning a specific electric bike here.

Can I Convert My Normal Bike to Electric?

Most conversion kits are DIY jobs. The bottom bracket conversion will be the most challenging and requires specific tools not found in most homes. Re-aligning the chainset, routing cables and ensuring a neat finish will be the longest task.

Any bicycle can be converted to electric with a motor and a battery.

Check the law around electric bike use on and off roads before you consider converting and how they differ from region to region. The penalties for breaking these laws can be very severe – eg. points on driving licence, invalid public liability insurance and significant fines.

Certain pedal assist systems increase speed beyond legal limits and require helmets, licensing and insurance because they are reclassified as light motorbikes – check the law before you convert. 

You need to check that your bike is suitable to take the fixtures and fittings required for conversion – eg. Does the battery pack fit my frame? Is my bottom bracket compatible? Can I afford to compromise the space on my handlebars from brake to brake?

Any bike warranty is likely to be void at the point you add the conversion.

IMAGE CREDIT: Swytchbike.com

How to Convert a Bike to Electric

You add a motor and a battery (which powers the motor) to your current bike. Sensors are fitted to detect pedal revolutions and speed to regulate the electric assistance given. An optional handlebar-mounted unit controls the amount of assistance given and monitors battery life as well as operating as a speedometer and odometer.

One method of adding the motor is via the hub of a wheel. This motor then drives the wheel forwards once it senses you are pedalling. Front or rear wheel options are available. 

This method is the most practical. The downsides are adding weight to the normal rotation of the bike.

Another method of adding the motor is to mount it below the bottom bracket, close to the pedals. Your existing bottom bracket, cranks and chainset(s) are replaced with the kit included with the motor. The pedalling action (provided by you and the motor) drives the wheel forward.

This method moves the centre of gravity of the unit lower down which sustains handling. The downside is the relative bulk of the unit and the compromise to the remaining aspects of the existing bike.

There is another method which does away with fixed amendments. An all-in-one motor, battery and friction-creating device clips onto the seat post. It propels the bike by creating friction with the existing rear tyre. This is convenient but the downside is the reliability of the connection to the rear tyre.

Electric motors can be added to a wheel hub or mounted to the bottom bracket.

E-Bike Conversion Kits

Swytch Kit

  • Front wheel with hub included (built and shipped to you)
  • Smaller battery pack clips on and off easily
  • Waterproof

This powered ebike wheel replaces your existing front wheel with a hub motor wheel, which is supplied to fit. This hub motor revolves the wheel once it senses forward motion from pedalling to give the assistance. The pulling power is said to work (via light pedalling) to a gradient up to 30%.

The power comes via a battery pack which clips onto handlebars, providing a stated range up to 19 miles/30km between charges. A full charge is not expected to be more than two and a half hours.

The power is activated when you pedal. The power pack receives a signal from a cadence sensor which clips around the bottom bracket area. You ride as normal and only receive the power as you turn the pedals. 

Rubbee X

  • Wireless system
  • Clip on and off installation – you retain your ‘normal’ bike
  • Range, speed and power increase as you increase battery power

This friction drive system requires little installation as the rugby-ball sized system locks onto the seat post. The rotating roller peeking out of the system should maintain constant contact with your rear tyre and drive it forwards. Detectors and the weight of the special rollers limit the chances of it slipping off.

The battery packs are modular and can be increased to supply more range, speed and power.

The power is activated as you pedal. The unit gets a nod from the cadence sensor fitted directly on the non-drive crank and only supplies the power at this point. On long descents, if you back pedal before freewheeling, a regenerative braking mode is enabled to feed the battery with some more units of energy.

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