Review: Swytch Electric Assist Kit for Brompton

Pros: easy to fit, effective assistance uphill. Cons: full price is rather steep
Swytch’s kit allows you to turn your Brompton into an electric assist one for less than a grand. Richard Peace finds out how easy it is to use

Swytch Folding eBike Conversion Kit £999 (£500 if pre-ordered)

Brompton’s own Electric model appeared in 2017, but there are still many retrofit options out there, including this one from Swytch.

The kit consists of: a replacement front wheel with a hub motor; a battery pack (power controls are on top of the battery and integral front light); a battery mount (frame or handlebar options); a pedal sensor; and an extended handlebar stem peg to allow folding with the handlebar battery mount in place.

“Installation typically takes 10 minutes,” Swytch says. It took me longer but was simple enough: fit a tyre and swap over the wheels; mount the pedal sensor and cable-tie the lead; attach the battery mount (a large, strong clamp); plug in the cables; then swap over the handlebar catch. As easy as that? Yes – with a couple of caveats.

I used the optional, Brompton-specific pedal sensor, which costs a bit extra and requires removal of the crank arm to fit. But it’s neater and less prone to damage on a folder than the larger sensor. Secondly, the motor’s cable run requires careful setup to avoid restricting steering. When riding, the power kicks in after a second or so of pedalling; this is a motion-sensor system, without the immediate response of torque-sensing systems.

However, it’s one of the better ones I’ve tried, without much delay or run-on, often a problem on poorly programmed kits. It zipped up the Pennine foothills emitting only a moderate hum. Range from the 252Wh battery was at least 20 miles, sometimes quite a bit more, despite being ridden mainly on power level four out of five. My only quibble was the lack of a handlebar control; the buttons are on the battery.

The kit is fairly lightweight, adding 3.4kg. Of that, 1.78kg is the battery, which is removable at the push of a button.


A neat, light retrofit kit that gives a great performance boost. As with the ‘official’ Brompton Electric, a wireless handlebar control would make it even better.

Other options

Nano Electric £785+ (kit only)

One of the most versatile Brompton retrofit systems (throttle plus pedal and pedelec options), with a long track record of reliable conversions.

Arcc Innovations Brompton with E2-pod £1,799+ (fitted, kit only)

A high-tech ‘Rolls-Royce’ system designed and made at Arcc’s plant in Cambridge.

First published in Cycle magazine, April/May 2020 issue. All information correct at time of publishing.

Our test promise

At Cycling UK and Cycle magazine, we are proudly independent. There’s no pressure to please advertisers as we’re funded by our members. Our product reviews aren’t press releases; they’re written by experienced cyclists after thorough testing.

Save money on your purchase through the Cycle to Work scheme

If your employer is signed up with a Cycle to Work provider, you could purchase the Swytch Electric Assist Kit for Brompton (or another piece of cycle equipment/a new bike) and save what you would have paid in tax and national insurance had you received the purchase price as salary.

That’s 32% if you’re a standard rate taxpayer and 42% if you’re a higher rate taxpayer.

In June 2019 the Cycle to Work scheme made it easier to buy bikes over £1,000.

Find out more