Electric Bike Motor Comparison: Hub, Mid Drive, & Friction Drive

Electric Bicycle Comparison

Electric Bicycles / September 3, 2021

For some cyclists, the idea of an electric bike – even a so-called ‘pedelec’ that supplements pedal power rather than replacing it – will always be cheating. On the other hand, what if having a little help, like a permanent breeze at your back, could open up a whole new world of cycling possibilities?

UPDATE: We have a much newer version of this article: Best electric bike: how to choose the right one for you

That could be carrying a week’s shopping on the bike, making a long or too-hilly commute doable, or riding to work every day of the week rather than just when you’re feeling top of your game. Or maybe an electric bike is what it takes for a family member or friend to catch the cycling bug.

In this guide we explain the different types of electric bike, what to look for when buying one and the current legal situation. For reviews of the latest models, see the 'electric' section of our Bikes & Gear browser, where you can search by price, star rating or brand.

Shopping, in a shop

We'd always recommend buying bikes from a good shop whose staff know their stuff, and this is especially true in the case of e-bikes. Electrical assist systems, although relatively simple, can go wrong no matter how good they are. If they do, then the peace of mind of going back to the shop you bought the bike from and chatting to people you know (and who know you – which is important) about a fault, or simply having a cuppa while they fix it, is worth any amount of money you could have saved by getting a cheap deal online.

Bike shops are rarely run as a business to make someone rich. They're run by people who enjoy bikes and want to make a living enjoying bikes. Having a friendly relationship with a good local bike shop can be, at times, priceless. They'll do all they can to help you, and keep you riding your bike (with or without electrics). Partly because this ensures repeat business so they earn a living, and partly because like all of us, they like bikes, they like riding bikes and they like people who ride bikes. As the e-bike market grows, there'll be more and more shops around that know the ins and outs of electrically assisted cycling.

Budget considerations

One of the things that's sometimes overlooked when buying an e-bike is the quality of the bike behind the electric gubbins. You need to remember you're buying a bike which has electrical assistance. If the electrics fail, what are you going to be left with? A decent bike? Or a heavy, odd shaped lump that's nothing but hard work to ride?

There are two key areas you have to pay attention to: what quality of bike you're getting, and what quality of electric assistance system you're getting. Both are equally valid, and will differ hugely depending upon the price. At one extreme, there are rubbish bikes with good electric assist systems. At the other, there are good bikes with rubbish electrics. In the middle ground are some models where both the bike and the electric system are good for the money.

Buying a poor bike with good electrics can be an option if you're good with bikes and like the idea of upgrading a basic machine. A good bike with a poor electric system is more or less useless, though – you might as well just buy a good bike. A good all-rounder will have compromises to both the bike and the electrics if it's cheap, but may be utterly wonderful if it costs a lot.

One of the main drawbacks of electric bikes is weight. Add an electric motor and batteries to even a fairly light base bike, and the result is a pretty hefty piece of machinery. Even lightweight e-bikes tend to weigh over 40lb. For comparison, you can pick up a sub-20lb road bike for less than £1, 000. Below 15mph the extra weight is okay because the motor takes the strain. But above that speed, more weight means more effort. Bear this in mind when buying.

Types of e-bike

Pedelec or twist-n-go?

There are two mains types of electric bike. The most common is what has come to be termed a ‘pedelec’. This type of system monitors the rider pedalling and automatically adds a certain amount of motor assistance – usually depending upon pedalling rate, pedalling force and bike speed (so it knows if you’re struggling and helps as much as possible for instance).

The other kind is a ‘twist-n-go’. This is where a switch is used by the rider to trigger the assistance from the motor. They can either be simple on/off affairs or a variable twist grip setup. Current regulations only permit the twist-n-go assistance to be delivered if the system detects the rider is pedalling.

Hub or crank motor?

Motor choice falls into two main types. Either it's mounted in one of the wheels (hub motor assist) or it's mounted at the crank and pedal area (crank motor assist) at the bottom of the frame. Typically, crank assist bikes have a reputation for dealing well with steep hills, but can be a little on the noisy side depending upon the brand and type. Hub motors tend to be very quiet, but often don't handle hills as well as crank assist systems.

The difference between the two is now much narrower than it was even just a year ago. As technology moves on, and the bicycle industry's application of existing technology from other markets evolves, we're seeing hub motor systems which cope well with hills, and crank assist systems which are almost silent (apart from the normal noises of a bike).

Source: www.bikeradar.com