It’s electrifying! The Brompton folding bike

The new Brompton Electric – around £2,700…sometime in 2018

After a few years of tantalising whispers and sweet nothings, Brompton has finally launched its e-bike in “selected cities”. Or at least you can reserve one. Given that the bike is as yet unproven and will cost around £2,700, what about a retrofit option?

The consensus seems to be that the best folding bike is the Brompton. It’s certainly not the cheapest, but it folds neatly, it’s relatively light and it rides like an agile real bike. Could it get even better if it were electric?

A new Brompton owner meets Arthur on his folding trike.

A new non-electric Brompton owner meets Arthur on his folding trike

The new Brompton Electric has a 250W front hub motor but still folds to the same size as a non-electric. The battery can be carried separately in a shoulder bag and has a USB charging port for mobile devices. A smooth ride is promised thanks to an integrated torque and cadence sensor.

A six-speed with battery will weigh just over 17kg, so very light for an electric. Budnitz make the lightest ebike (at around 15kg), which has the ride advantage of being a full-size bike, but doesn’t fold, of course. And the Kalkhoffs are the most refined for ride and equipment.

Brompton will charge you £200 for a place in the queue, and you’ll then get to place an actual order in mid-2018. Hmmm. Read on…

The alternatives to an official electric Brompton

Nano Electric Bikes in Leamingtom Spa (and Marlborough) is a small company that specialises in electrifying Bromptons. They sell kits for home-fitting, will install for you on your existing Brompton or they’ll order a new Brompton for you and electrify it.

We spent a few hours testing their three options a while ago – a pedelec system that means the electric drive won’t start until you start pedalling, a twist throttle and a thumb throttle. It was fun, very tempting and not without a few caveats…but more on those later!

Folding bikes are great for camping, and especially for campervanners without a lot of room who want to be able to leave the van or motorhome on a site and still have transport. The hills, though, can be a problem! Wouldn’t it be great to have a little help from time to time.

Our test bikes

thumb_IMG_3421_1024The Nano kit involves fitting a lightweight motor into the front hub (which entails expanding the forks slightly and so won’t work with titanium forks). A small controller is fitted to the front stem and a control is added to the handlebars. The battery – a choice of 5ah, 10ah or 4ah power tool battery goes into a Brompton bag and the normal bag connection is fitted with contacts. Take the bag off and the battery stays in it, leaving you with an almost ‘normal’ bike again.

There are three handlebar control options – a push button control on the handlebar for low, medium or high assistance, a twist throttle or a trigger throttle. The law changed in 2016 to make it illegal to have a bike that would move without any pedalling. So, with all these options, a sensor next to the pedal tells the bike when to zoom. It doesn’t start until you put in a teeny bit of effort first.

Thumb throttle

Thumb throttle option – our favourite

Twist throttle

Twist throttle option

If you happened to buy your  electric bike before January 2016, you’re still legal in the UK. In Europe, though, pedelec has been the only legal option for a while. That means you’ll need to think about whether you’re happy to take the (apparently low) risk of being stopped by the Spanish police for going up a hill without effort!

You’ll also want to consider resale issues on non-pedelec bikes.

Controller nano

The controller

Front hub motor

Motor discreetly fitted into the front hub – forks slightly widened.

Twist and gos – bikes that can be powered by a throttle alone – now require type approval. It’s something an individual bike owner could do, but it’s more likely that larger manufacturers will type-approve particular models before selling. If the power of throttle-only bikes cuts out at 15.5mph, they won’t be considered as motor vehicles so won’t need registration, tax, insurance and rider licensing.

So what are they like to ride?

We tested all three Nanos, and all three were superb fun to ride. The pedelec was our least favourite because there was a sight delay in the power kicking in, which made it feel a bit jumpy. We also had an issue with the power refusing to come on at all rather randomly when going up one hill. Nano tell us that their redesigned models for 2016 have reduced that delay to make pick-up quicker. We’ll report back when we’ve tested them.

The twist throttle was far more intuitive as a speed control than the push button. Pull it back further and you go faster. However, even if you’re not using power and are just pedaling, you’re now holding a twisting handlebar end, which didn’t feel all that stable or comfortable.

The best option was the thumb trigger. You still get a solid handlebar to hold and a push down with the right-hand thumb gives you smooth power when you need it.

The kits didn’t add much to the weight, though we would choose the 4ah power tool battery over the far heavier 10ah. You can’t go as far on a charge (10 miles or so against 40), but you could carry two batteries and they’re cheaper and more available (they just connect inside the bag with an easy push connection). You can fly with them too.

The verdict

Three options nano

One of Nano’s options is 4ah batteries – the ones you get for cordless power tools.

Nano with big battery

Batteries fit neatly into Brompton front luggage and connect with contacts on the standard bag mount.

So would we get one? Definitely. It’s great to start pedalling and feel superhuman. It would actually make us cycle more because there’d be no disincentive of hills (we’re in the Pennines!).

A downside is that one of the first adaptations a Brompton owner makes is to change the basic foam grips for something more comfortable. With a bit of cutting down and careful positioning, Ergon’s GP2 (S) are just the job for a far more comfortable ride and better steering. You can’t do this and have Nano’s controls. The other downside is that the modification will void your Brompton warranty.

If you do go for an electric folding bike, we’d really recommend having a bag to store and carry it in. It keeps it clean and concealed when left in the car, campervan or the porch at home.

The Kalkhoff Agattu electric bike

The Kalkhoff Agattu electric bike

Alternative electric options

The other conversion kits out there, by the way, are the Sparticle and the Bespoke E-bikes. We haven’t tried these, but would love to hear from anyone who has. Or you could buy a built-as-electric folding or standard electric bike (have a look at our Kalkhoff review here, for example). The Kalkhoffs are some of the nicest we’ve seen, but electric bikes are improving all the time.

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  1. I have had a Brompton adapted by nano bikes for six years and it been the best investment I’ve ever made we have cycled all over the continent and many of the cycle trails in England we take it everywhere and cycle. It’s reliable and I have never had any problems .

  2. Thank you for mentioning Bespoke e-bikes in your article. We have recently converted a Brompton using the german Pendix crank drive system which can be fitted to any multi geared bike. See our web page for our full range of new full size and folding electric bikes and conversions.

  3. For a folding bike the go cycle seem to be highly popular and look good. I prefer a trexking bike for my camping. Moustache bikes are amazing and with a good bike carrier tow bar mounted forget the foldable bikes. Just a quick tip that you can get tax free bike schemes through employers.

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