Best Electric Bikes For 2021

Matthew Knight

In this article

Electric bikes (e-bikes) are a fantastic way to rediscover a love for cycling, or extend your enjoyment into your later years.

They don't come cheap though, and we've found that some will take you much further than others.

Some e-bikes won’t even get you up a 1.2% incline, and will only take you 30 miles on the flat. The best we've tested will have you climbing hills with ease and power you along a flat road for nearly twice as many miles.

Like with any new bike, you'll want to try out a few options before you buy, but while a trial will give you a good feel for how the bike handles and how comfortable it is, it won't tell you how far it will go and how helpful it will be on the hills.

Our independent e-bike tests focus on the bits of an e-bike that make the biggest difference to performance: the motor, battery and display unit, and tell you which combinations will give you the most support for longest.

Best E-bikes for 2021

We've tested 15 of the most common electric bike motor, battery and display combinations. Each one is found in a range of different e-bikes, so you can use these results to narrow down your search to the e-bikes that will power you up hills, deliver a smooth and consistent ride and be easy to use.

Only logged-in members can view our recommendations in the table below. If you're not yet a member, sign up to Which? today for instant access to this and all our reviews.

	Range on flat terrain	Hill support	Display unit	Overall score
M	40 miles	★★★★★	★★★★★	80%
M	This is the best electric bike motor and display combination we tested at our lab. The motor is quiet and provides fast acceleration. It also delivers power smoothly and gives brilliant support on flat terrain, and also on tough hills. The display is clear, even in bright conditions and is very easy to use. If you opt for a bike with a large 500Wh battery you’ll get almost 40 miles of electrical assistance on the flat, if you use the highest assistance setting. You can extend the range further if you lower the level of assistance. On steep hills, you’ll still be able to ride for a little under 16 miles with full assistance. A bike with a smaller battery, 400Wh and 300Wh batteries are common, will mean that you can’t ride as far with assistance, 33 miles and 25 miles respectively, on the flat. To find out which motor we are talking about log in now or join Which? today.
	Range on flat terrain	Hill support	Display unit	Overall score
M	40 miles	★★★★★	★★★★★	77%
M	This is the best all-round electric bike motor that we’ve tested, but paired with a slightly inferior display and control unit. When paired with a 500Wh battery, you’ll get 40 miles of riding on the flat on the maximum power setting. That drops to 16 miles on a steep gradient. You can buy this motor with 300Wh, and 400Wh batteries too, which will reduce the range of the bike, but you’ll still get the same smooth riding. The motor accelerates exceptionally well, is one of the quietest we’ve tested and is brilliant at supporting your riding on flat roads or hilly terrain. To find out which motor we are talking about log in now or join Which? today.
	Range on flat terrain	Hill support	Display unit	Overall score
M	43 miles	★★★★★	★★★★★	72%
M	This motor will take you almost 43 miles on the flat and a little over 13 on a steep hill, when paired with a 400Wh battery. It’s a good, quiet, motor and very smooth with its power delivery. It also accelerates you quickly and without jerkiness up to top speed. The display is the best we’ve tested. It has four assistance levels, provides clear information and is very easy to use. To find out which motor we are talking about log in now or join Which? today.
	Range on flat terrain	Hill support	Display unit	Overall score
M	70 miles	★★★★★	★★★★★	71%
M	This motor will power you for 65 miles on the flat and an impressive 21 miles on a steep hill, assuming you opt for a bike that also comes with a 500Wh battery. Smaller batteries will reduce the range. The motor accelerates you very smoothly and quickly up to top speed and it really comes into its own when powering you up either gentle slopes or steeper climbs. The delivery of power isn’t as smooth as some other motors, particularly on flat terrain, but in general this is a high quality motor that you won’t be disappointed with. The display has three assistance levels, but we didn’t find it as clear or easy to use as other displays that are available. To find out which motor we are talking about log in now or join Which? today.
	Range on flat terrain	Hill support	Display unit	Overall score
M	70 miles	★★★★★	★★★★★	70%
M	The Shimano Steps E5000 is a good electric bike motor, that’s relatively quiet and provides good electrical support, its range is particularly good on flat roads. But it struggles more than the very best on hills. The SC-E6100 display is also clear and easy to use. It provides three differing levels of assistance. With a 500Wh battery you’ll get a whopping 70 miles of riding on the flat on the highest power setting. That drops to 56 miles for a 400Wh battery and 42 miles for a 300Wh battery. On the hills the range isn’t quite as extensive, but you still get almost 18 miles on full assistance from the 500Wh battery. To find out which motor we are talking about log in now or join Which? today.
	Range on flat terrain	Hill support	Display unit	Overall score
M	64 miles	★★★★★	★★★★★	70%
M	If you buy a bike with a 500Wh battery you’ll get 64 miles of support on the flat on the highest power setting (51 miles and 38.5 miles, respectively, if opting for a 400Wh or 300Wh battery). It’s a high quality motor with incredibly smooth delivery of power to the pedals during acceleration, which is sharp and crisp. The motor is also quiet. It’s not quite as good on steep hills, and the motor does have a tendency to noticeably jump in and out as it reaches top speed (causing a bit of a yo-yo effect), which contributes to the motor not getting one of the highest test scores. To find out which motor we are talking about log in now or join Which? today.
	Range on flat terrain	Hill support	Display unit	Overall score
M	52 miles	★★★★★	★★★★★	69%
M	This is a good quality motor that’s paired with a clear and easy to use display that has four assistance levels. The efficient motor gives an extensive range from a 400Wh battery of over 50 miles, which is impressive. You’ll also have almost 16 miles of assistance on the highest power setting on steep hills, too. The acceleration of the motor is exceptionally quick, responsive and smooth. To find out which motor we are talking about log in now or join Which? today.
	Range on flat terrain	Hill support	Display unit	Overall score
M	32 miles	★★★★★	★★★★★	65%
M	The range of this motor and battery combination isn’t as extensive as some, but could be extended to as much as 54 miles with a 500Wh battery. The range is much shorter on steep hills, less than 10 miles on full assistance on a steep gradient. It’s a good motor with no major flaws. The consistency and smoothness of the power delivery is a particular strength of this motor, it’s also quiet. We liked the display, which has four assistance levels. It’s visible in bright conditions and it’s clear and easy to use. To find out which motor we are talking about log in now or join Which? today.
	Range on flat terrain	Hill support	Display unit	Overall score
M	61 miles	★★★★★	★★★★★	60%
M	You can find this rear hub motor in some of the most popular electric bikes you can buy. The range from a 400Wh battery is extensive on the flat, and you’ll get 15 miles on the highest setting on a steep hill, too. The motor also accelerates a bike promptly and smoothly up to the maximum speed. It’s when the motor gets up to top speed where the problems with this motor lie. It tends to abruptly cut off the power, which leads to a bit of a yo-yo effect as the motor cuts in and out when you’re cruising at 15.5mph. The best motors manage this top speed cut off a little more smoothly. The motor is also a little noisier than most. To find out which motor we are talking about log in now or join Which? today.
	Range on flat terrain	Hill Support	Display unit	Overall score
M	40 miles	★★★★★	★★★★★	53%
M	The display isn’t as slick as many alternatives. It’s large, a little clunky and not as easy to use, or as easy to see in bright conditions as the best on the market. The motor is good though, delivering smooth power to the pedals on flat or hilly terrain. From a 500Wh battery you’ll get a quite disappointing 40 miles of range on the highest setting on a flat road. On a steep hill you can ride for 15 miles on full assistance. To find out which motor we are talking about log in now or join Which? today.
Last updated: 01 April 2021

How we test electric bikes

All of the e-bike motor systems we test are set up on a rolling road in a lab and put through an array of tough tests designed to simulate real-life use. We use the same setup to test all the different systems, so that you can easily see how they compare.

How we calculate electric bike range

You won't find range figures for e-bikes that are truly comparable anywhere else. Manufacturers may give a mileage figure on their electric bikes, but they often won't publish the weight of the rider or the conditions they are riding in. Trying to compare range with another bike is therefore almost impossible.

For our range tests we keep the following constant:

Weight of the cyclist (70kg)
Frontal area and air resistance
Rolling resistance of the tyres
A constant speed of 12.4mph is maintained when the bike is up to speed
When the bike is on a slope of 6% that speed is reduced to 11.7mph

Assistance levels

We conduct our range and incline tests on three separate power assistance settings:

100% assistance - motor is putting in the same effort as the rider
150% assistance - motor is putting in more effort than the rider
200% assistance - motor is putting in twice as much effort as the rider

Different cycling terrain

Each e-bike system is tested on a flat road, a shallow hill (1.5% gradient), and a steeper hill (6% gradient).

Many of the motor systems we've tested can not provide all of the levels of assistance described above on even a shallow hill, making them unsuitable for hilly areas.

Expert riding assessments

Each e-bike motor system is assessed for the following criteria:

The smoothness with which it delivers power to the pedals - some motors are noticeably juddery when delivering power.
How well it accelerates from a standing start - some systems don't deliver power until after a few pedal revolutions, making it more difficult and less safe for a rider setting off and getting up to speed.
Noise - some motors emit an irritating whine, which could be distracting and ruin your afternoon jaunt through the countryside.

Display unit

The display unit is rated for how easy it is to use, for example switching between assistance levels, and the visibility of the data it displays in various light conditions.

Best electric bikes for 2021

Best E-bikes for 2021