The bicycle is surely one of humankind's greatest inventions. But has the technology really moved on that much in the last century? Sure, bikes have lost weight, gained gears, they're smoother, roll more easily and stop better. But when all's said and done you still have to do the work – it's not moving along without you.
But what if it could give you a helping hand? What if the ultimate upgrade wasn't (just) a set of Spokey-Dokeys, but the ability to turn your regular bike, no matter how humble, into an electric one?
We've lined up three e-bike converter kits that you can add to your current bike for a bit of a boost – and remove if you have to leave it somewhere. All are fully compliant with UK regulations and were designed and developed here too. These are not cheap kits that are going to explode in your front porch. Nor are they going to rocket you up hills at 40mph. Sorry. You're still going to have to do some pedalling.
What they will do is help take the sting out of your rides. No more sweaty and dishevelled stumbling into the office on the commute. They might convince you to leave the car at home if the weather's good. Or pedal to the pub to see your mates. Or the park for Sunday footy. In other words: your bike, multiplied.
SWYTCH
Why not just buy an e-bike? Simple answer: cost. A vaguely reputable e-bike is a thousand quid, but for half that Swytch will sell you a kit that can be fitted to almost any conventional bike. Secondary answer: security. An e-bike is a theft magnet – with these, you can remove a good chunk of the expensive tech and carry it with you.
All three kits consist of the same basic elements: a battery to store energy, a motor to deploy it, and a sensor to decide when to do that. The Swytch separates these out, linking them with cables. There's a wide variety of batteries to choose from and places they can be mounted around the frame, but this £499 Max+ kit is designed to sit on your handlebars as it contains a built in ‘be seen' light ring. A sensor sits on the pedal arm, calling up assistance from a motor that's mounted – and here's the unusual bit – in the front wheel. That's right, this is a bike with two driven wheels.
All you do is switch out your existing wheel (you can choose to replace the rear instead of the front), run the cables around the frame, mount the battery, sensor and you're away. The Max+ battery has a 275Wh capacity (Another £100 buys you the 362Wh Max++) and is good for a claimed 30-40 miles.
Capable of delivering up to 250 watts, it is effectively you, doubled. Plus it develops 40Nm of torque, which is just the thing for getting away from traffic lights. As with the others, there's a 25kmh (15.5mph) assistance limit – go above that and you're on your own. The Max+ battery weighs 2.2kg, and the rest of the kit adds about the same again. When you stop and lock the bike up though, the battery unclips to take with you. You can recharge it – or discharge it further – an integral USB-C port means it doubles as a power bank.
On the move, an optional wired display allows you to switch between five levels of assistance. Choose level one to maximise range, or five for nonchalantly leaving roadies in your wake. Accessories include a twist throttle – just remember that unlike a motorbike, if you stop pedalling no amount of twisting is going to wake the motor. Nevertheless, the Swytch Max+ (swytchbike.com) is the most affordable and adaptable of these e-booster kits.
VERDICT
Turn it on, start pedalling, and Swytch chips in to help out. So there you are, cruising silently along at 15mph (it's the quietest of these three) and letting the bike do all the hard work – provided the pedals are moving, however slowly, the motor will contribute, so you can cheat the system.
The Swytch does have a couple of quirks though. Every time you stop, it takes a couple of pedal revolutions before the motor wakes up – frustrating if there's a line of traffic lights ahead. And with all the weight on the front of the bike, the Max+ system can be a bit awkward to handle at low speed or if you're on a loose surface. Front-wheel spin is a possibility. You might want to choose the less pretty, more affordable, frame-mounted Swytch Go (starting from £349) instead.
But on the whole, the Max+ is an excellent value, attractively designed kit that delivers on its range and power promises. It's waterproof to IPX6 standards (in other words, it's more tolerant of rain than you are), but with the cables running around the frame, once you've converted your bike, you're unlikely to unconvert it. If you want to have the choice to ‘e' or not to ‘e' with your push bike, then you will need something different.
From £499, swytchbike.com
SKARPER
The other systems here are aimed at commuters and urban riders. Simply fit the kit to give your old bike a new lease of life and get to work less of a sweaty mess. The Skarper (skarper.com) is more versatile.
Where the others feature removable batteries, but leave the motor, cables and sensors attached, Skarper thinks differently. Rather than a motor in the hub, here it's built into a sleek 4.2kg box that houses the battery and control electronics as well. When you lock your bike up, Skarper unclips in two seconds and the only component left behind is the rear disc brake.
Have a close look and you'll spot some unusual holes in it. This is how Skarper connects to your bike – with locator pins, a locking mechanism and – most importantly – a driveshaft. Capable of delivering peak torque of 76Nm (over 30Nm more than either rival) it puts a lot of stress through the slender shaft, so Skarper needed the materials and engineering expertise of Red Bull Advanced Technologies (the F1 team's offshoot).
The 240Wh battery is marginally the smallest here, meaning a claimed range of 30 miles, but it's the fastest to charge (2.5 hours rather than four). It also has the most comprehensive control electronics, with a built-in inclinometer so it knows when you're heading uphill and can chip in a bit more, plus the removable sensor on the pedal arm is a Bluetooth-linked accelerometer, rather than a simpler wired torque sensor. This all allows the Skarper to operate more smoothly.
Mount your phone on the bars and you can control Skarper through the app to switch between Eco, Cruise and Turbo modes and keep an eye on battery level. Want to save battery for later? Pedalling backwards for three rotations turns the system off – and back on again.
Because it's so easily mounted and removed, and leaves so little trace on your bike when it's not there, the use cases expand: it'll do the commute, but it can also help you keep up on group rides. Skarper has a converter for bikes with rim brakes. Some bike brands are now offering Skarper as their in-house e-bike solution rather than designing and developing their own unique models.
It's a beautiful, clever piece of engineering. Which is why it costs £1495. Still, that's cheaper than most e-bikes.
VERDICT
The Skarper is the most intuitive and most powerful e-bike converter here. It might be expensive, but it justifies that by delivering levels of torque the others can't match and doing that in a way that, in Eco and Cruise modes, seems to accurately second-guess what you want. It gives you what you want, when you want, so comes across as more integrated and thoughtfully developed than the others here.
There's no lag or waiting when you set off, the torque is instantly there and although Skarper looks vulnerable mounted so low down on the frame, we had no issue with either kerb strikes or catching a heel on it. Actually, it's positioning not only counteracts the weight of the regular drivetrain on the other side, but means the bike handles more naturally. Even with the system turned off, the bike isn't a pain to pedal.
The only real downside is that it's the noisiest system of these three, so you're less likely to fool other bike-riders into thinking you're doing it all yourself. The flip side is that everyone will want to talk to you about it. It's a super-satisfying piece of design and technology, there if you need it, gone if you don't. Two bikes in one.
£1,495, skarper.com
BOOST
Think of Boost as a tech ecosystem. Yes, there's a converter kit similar to Swytch, but there's also a bespoke Boost urban bike, and a BatteryIQ app designed to alleviate fears about potential battery fires. In other words Boost has thought around the issues of e-bikes and come up with solutions.
Core tech first though. Like Swytch, you need to change a wheel – the rear, in this instance, which comes in a wide array of sizes to work with almost all bikes. It includes a sensor built into the hub that detects your inputs through the drivetrain, so no need for anything on the pedal arm. Then you simply drop the battery pack into the bespoke bottle mount on your frame, where it locks in place with a key.
The lightweight 1.4kg pack contains the control electronics and a 252Wh battery – a neat piece of packaging. All told the kit adds around 4kg (on a par with both rivals) with the motor delivering peak torque of 42Nm. Claimed range is 35 miles, although as ever that depends on how hard you're making it work. Like Skarper, there are three modes: Eco,
Boost and Super Boost (giving you full power for a 20-second burst). Control comes via an app, or a separate £59 wireless display.
The system itself costs £695. Boost (boostbike.uk) recommends you have it fitted at one of its retailers (another £100), but if you want to save money and have some engineering nous, then you can buy the basic kit for £522 and build it at home. However, as with Swytch, once fitted, it's unlikely you'll want to unfit it – this doesn't have Skarper's broader remit. But park it up, remove the battery and it's going to be pretty hard for anyone to spot anything different about your bike. There's less cabling than Swytch, so it's a stealthier solution.
Alternatively, for £1,245, Boost will sell you a complete bike. Aimed at urban riders and commuters, what sets this 16kg e-bike apart is its slim design on 20in wheels. It's not a full Brompton-style fold-up, but it's designed to fold flat for storage in narrow hallways, thanks to flip-in pedals and bars that turn through 90 degrees.
The battery also links to your phone through another app, BatteryIQ, to give you in-depth information about cell health, temperature and voltages. Basically, it tells you that all's well and it's not about to catch fire. Boost is hoping to sell this tech to other firms.
VERDICT
Boost by name, not massively boosty by nature. Even in its higher Boost mode it's a little parsimonious at handing out the power – good for battery range, not great if you want a good jet of power off the line. You should be able to get that by selecting Super Boost, but again, that's not a mode that lives up to its name – plus it cuts out after 20 seconds.
As with Swytch there's too much delay between setting off and the motor waking up. With Swytch you feel the extra torque sweep in but don't hear it, while here it's the other way round. The motor whines but power is modest. Use the app rather than the optional display – it's got better information, more logically displayed.
To be fair, motor control at lower speeds is good, with Boost doing a better job than Swytch at working out how much torque to add depending on the power you're putting in. And as fitted to Boost's own bike, the system is great for dealing with tight urban spots and around pedestrianised areas. But for cycling in more open, freer-flowing areas, the others do it better.
£695, boostbike.uk