E-Bike Motor Systems Compared: Bosch, Shimano and More

Mid-drive versus hub motors

E-bike motors come in two broad types, and it is the first thing to work out on a used bike. A mid-drive motor sits at the cranks, in the middle of the bike, and drives the chain. A hub motor sits in the centre of the front or rear wheel and drives that wheel directly.

Mid-drive motors put the weight low and central, which makes the bike handle more naturally, and they drive through the bike's gears, so they climb hills well. Hub motors are simpler and often cheaper, and they suit lighter, tidier-looking e-bikes, but they do not use the gears and can feel less punchy on steep climbs. Most quality e-bikes built for hills, distance or off-road use a mid-drive.

Bosch

Bosch is the market leader and the system you will meet most often on a used e-bike in the UK. The range runs from the Active Line for relaxed town riding up to the Performance Line CX, a high-torque mid-drive of around 85Nm that is popular on electric mountain bikes. Bosch motors are smooth, well proven and, importantly for a used buyer, widely supported: parts and dealer diagnostics are easy to find here, and the display can show useful information about the system.

Cyclesite Tip. On a used e-bike, how easy the motor is to service in the UK matters as much as how it rides. A well-supported system like Bosch is cheaper to live with if something needs attention.

Shimano STEPS

Shimano's e-bike system is called STEPS, and it spans town bikes up to the EP8 and EP801 mid-drives used on many electric mountain bikes, again around 85Nm. Like its gears, Shimano's motors are well supported across UK bike shops, which makes servicing and parts straightforward. A used bike with a Shimano STEPS motor is a safe choice on the servicing front.

Specialized, Brose and Mahle lightweight

Specialized fits its own motors, built with Brose, on bikes like the Turbo Levo and Turbo Vado. These full-power mid-drives are quiet and smooth. Specialized also builds a lighter range, the SL bikes such as the Turbo Levo SL and Creo, which use a smaller, lighter motor for a more natural ride and less assistance.

Mahle makes the lightweight rear-hub systems, the X20 and the older X35, found on lightweight road and gravel e-bikes from brands like Orbea and Ribble. These are lower torque, roughly 40 to 55Nm, and are designed to be discreet and light rather than powerful. They are controlled through an app and a small remote. They ride beautifully, but check that the system is supported before buying an older or less common one.

Yamaha and others

Yamaha builds reliable, powerful mid-drives and also supplies the motors behind Giant's SyncDrive system, so a used Giant e-bike often has Yamaha underneath. Fazua makes a light, removable motor and battery unit found on some road and gravel e-bikes. Bafang motors turn up on budget e-bikes and most conversion kits, in both hub and mid-drive forms.

What matters when buying used

On a used e-bike the ride quality of the motor matters less than three practical things: whether the system is still supported in the UK, the health of the battery, and whether the motor throws any error codes. A mainstream system from Bosch or Shimano is the easiest to service and the safest bet second-hand. A less common or older motor can ride very well but be slow and costly to fix.

Whatever the motor, check the battery health first, as it is the biggest cost on a used e-bike. Our used e-bike battery guide covers how to do that, and the used electric bike guide covers the wider checklist. When you are ready, browse used electric bikes with the motor and battery stated on every listing.

Common questions

Which e-bike motor is best?

There is no single best motor, but for a used buyer Bosch and Shimano are the safest choices because they are powerful and the easiest to service in the UK. Lightweight systems from Mahle and Fazua ride beautifully on lighter bikes but offer less assistance and can be harder to support. Choose the bike that fits and rides well on a well-supported motor.

Are mid-drive or hub motors better?

Mid-drive motors place the weight low and central and drive through the gears, so they handle naturally and climb well. Hub motors are simpler, often cheaper and suit lighter bikes, but they do not use the gears and can feel weaker on steep hills. Most quality e-bikes built for hills or distance use a mid-drive.

Which e-bike motors are easiest to service in the UK?

Bosch and Shimano are the most widely supported, with parts and dealer diagnostics easy to find across UK bike shops. On an older or less common motor, confirm that parts and support are available here before you buy.