The best electric bike conversion kits for different riders and bikes

The best electric bike conversion kit depends on what sort of cyclist you are. Here at Boost we’re clear that the best electric bike is the bicycle you already own - just upgraded to be electric. It’s cheaper, lighter and better for the environment than buying a new (heavy and expensive) ebike and just as effective.

But with several different types of conversion kit to choose from, here are the best kits for different types of rider and owner.

Best for ...Rear wheel (EG Boost)Mid driveFront wheel (EG Swytch)
Beginner level mechanics✅ (shop fitted)  
Confident bike owners✅ (self fitted)  
Advanced mechanics 
Handling 
Commuting  
Steep hills  
Mountain biking  
Brompton  
Other folders  
Speed of bike
Speed of fitting  
Reliability 

Boost vs Swytch: why we think Boost is better.

How conversion kits work - and different brands compared.

Best for your maintenance level

  • Beginner: If you head to the bike shop to deal with punctures, you might want to do the same with your bike conversion kit. Although it’s simple to fit, this probably shouldn’t be your first more advanced maintenance task. Unlike most kit suppliers, Boost has relationships with many bike shops and it costs £50-100 on top of the kit to fit it. You can find a kit shop here. Best kit: Boost rear wheel - shop fitted.
  • Confident: Fitting a rear or front wheel hub kit involves replacing your current wheel with a new one that contains a motor in the hub - you then connect that to the battery and its controller. The kit installation will seem simple if you’re happy replacing tyres and adjusting gears and brakes. With the Boost kit, you can order the rear wheel with the cassette (the sprocketed discs that form the gears) already fitted, reducing the tasks you need to do. Best kit: Boost rear wheel - self fitted.
  • Advanced: If you’re a much more comfortable bike mechanic, you could also consider the other type of bike kit - a mid drive. Although they can feel the most natural form of assistance, they require careful fitting and you need to be absolutely sure your frame is suitable for the kit. Beware of cheap models from unknown brands with dubious quality. Best kit: Boost rear wheel / branded mid drive - self fitted.

Best for handling

You’re already familiar with the handling of your current bike - so you won’t want it to change much when you change it to electric. The upgrade will make some difference as the kits weigh up to 4kg which has to go somewhere on the bike. 

Mid drive kits make the least difference to handling as they are positioned where you pedal.

Of the rear and front wheel options, rear wheel drive will feel more natural. The rear is where the bike is driven from and there’s already usually more weight on the back of a bike (it’s where riders tend to hang bags etc). The Boost is so lightweight at under 4kg that you won’t feel much difference.

Front wheel drives on the other hand, can feel very different - as if the bike is pulling away from you and with more weight in front of you changing the feel of the handlebars. 

Best kit for handling: Mid drive then rear wheel

Best for commuters

Kits come into their own for commuter road bikes. A cheap, easy way to upgrade your bike and arrive at work faster and less sweaty.

With most home to office journeys in the UK being relatively flat, you just want a kit that has natural handling and helps you get away from traffic lights quickly. The Boost’s light weight, low cost and quick response time when you start pedalling fits the bill. 

Best for commuters: Boost rear wheel

Best for steep hills

If your regular cycle has steep hills of more than 8%, you won’t feel much assistance from front or rear wheel kits - it’s here that a mid drive will come into its own as you will naturally be applying more of your own power through the pedals.

Best for steep hills: mid drive

Best for mountain biking

If you’re cycling on grass or gravel, then it’s fine to upgrade your existing bike with a rear-wheel kit. But if you’re doing proper off-road or mountain biking again a mid drive will be much more responsive and provide better assistance.

Best for mountain biking: mid drive

Best for folding bikes

Because the wire from the controller has to be connected to the wheel, rear-wheel kits aren’t recommended for folding bikes as the folding bracket can damage the wire. Boost has a Brompton specific ebike conversion kit that avoids this issue. For other folding bikes, a front wheel kit is best. 

Best for Brompton folding bikes: Boost rear wheel kit

Best for folding bikes: front wheel kit

Best for speed of bike

To be road legal in the UK, all conversion kits must stop providing assistance when you reach 15.5mph. Do not buy a kit that exceeds this limit - you can be fined, your bike confiscated and get points on your licence. They are also dangerous. 

Best for speed of fitting

With wheel driven kits, you are sent a new wheel (the hub of which contains the motor) and it takes only 20 minutes or so to fit it. Because the wheels are custom built here in the UK, it takes Boost under two weeks usually to send you the wheel. Other kit makers don’t hold stock and wait for sufficient registration before ordering parts which often means long delays. 

Best for speed of fitting: Boost rear wheel

Best for reliability

Electric bike conversion kits can put more strain on your bike - you are fitting it with a motor, after all. You’ll want to make sure spokes aren’t already damaged, the chain isn’t worn, and your brakes are still working well (as the bike will now be heavier). There are other potential issues with some types. 

  • Mid drives have the motor fitted under the bike. Water penetration is an issue as is physical damage from the surface you’re cycling on. Mid drive motors also significantly shorten chain life as the motor adds force to the pedals so always use a high quality chain.
  • Front wheel drives put strain on the forks as they aren’t designed to hold the forces that come with pedal- or motor-driven wheels. There have been many instances of forks cracking from front-wheel drive systems.

Overall, we think rear wheel offers the best approach to reliability (they actually reduce pressure on the chain as some or all of the load is taken up by the motor) and we also offer help from a UK-based support centre if you ever do have an issue. 

Best for reliability: Boost rear wheel

FAQs

What is the fastest ebike conversion kit?

The fastest ebike conversion kit to fit is Boost - under two weeks to be sent a custom-built wheel and less than 20 minutes to fit it. 

Are electric bike conversion kits worth it?

Upgrading your current bike saves money and CO2 compared with buying a new ebike - but you still get all the speed and effort benefits of an electric bike. A quality ebike conversion kit can often be even better than a new ebike.

Are ebike conversions legal in the UK?

As long as the motor is 250W and assistance is applied only when you pedal and at speeds of 15.5mph or less, then there is no legal difference between an electric bike and a standard bike. You can ride them in the same places and the same rules apply. Boost kits meet these EAPC rules.

How fast is a 250W ebike?

Road legal electric bikes can only provide assistance up to 15.5mph. You can cycle faster than that but it will all be down to your pedal power (or going downhill).