Brompton C Line 12-Speed Explore Review: This Is My Kind Of E-Bike

Part of a new breed of e-Bromptons, the C Line 12-Speed Explore mixes fold-up utilitarianism with impressive pedal assist and a 45-mile range.

Brompton’s iconic folding bikes have been around in one form or another since 1975. Since then they’ve attracted something of a cult following and become a firm favorite with urban cycling commuters the world over. The company’s new C Line and P Line of electric folding bikes retain that classic Brompton design. (The battery is stealthily disguised as the old front pannier bag.) So can a small-wheeled folding bike earn a place among our best electric bikes guide? MF’s resident bike enthusiast and veteran cycling commuter Laurence McJannet jumps aboard to find out.

I took delivery of my ‘pop lilac’ colored electric C Line Explore 12-Speed Brompton (buy now) just a few weeks before the Brompton World Championships. Running since 2006, this event alone underlines how iconic the Brompton folding bicycle has become. I can’t think of any other make of bike – or car for that matter – that has become so popular it has its own dedicated world championships.

I was disappointed to learn that no electric bikes are allowed in the BWC. So no opportunity there to exercise my competitive streak. Still, as I opened the box, I was keen to see what this compact pocket rocket could do. (The box is barely bigger than the folded bike, which measures 64.2 x 58.4 x 26.9cm / 25.3 x 23 x 10.6in.)

I have to admit I’ve had a chequered history with Brompton bikes. I’ve predominantly been a competitive road and mountain biker, building my bikes with lightweight components to make then quick and nimble for racing. So when I was presented with a three-speed hub-geared Brompton for a cycle map surveying job almost 20 years ago, the experience was something of an eye-opener. The upright riding position was alien to me. The small wheels made my centre of gravity feel too low. They also made the bike feel super twitchy. And that leather Brooks saddle would not shape itself to my posterior no matter how long I rode on it.

Brompton C Line Explore 12-Speed design

Fast forward to 2024 and the Brompton C Line Explore 12-Speed (buy now) is an altogether different experience. Taking in out of the box I felt the familiar heft of the folded machine. The design is relatively unchanged, with a hinge on the top tube (the Brompton has no down tube as such) and head tube. That allows you to fold the bike rapidly down small enough to jump onto trains without needing to find dedicated bike storage.

The saddle effectively becomes the handle as soon as you fold the bike down. And that was the first thing I noticed as soon as I pulled it out of the box. Gone are the pricey Brooks saddles of yesteryear. Brompton now uses its own proprietary saddle which seemed encouragingly softer and narrower than the old Brooks one.

Unfolding the Brompton evoked some long-dormant muscle memory. Within 20 seconds I had flipped out the rear triangle (though it now has a lock lever), unfolded the bars, clamped the top-tube hinge and flipped up the one folding pedal. All that was needed was to clip the battery (and control panel) onto the front – where the original panniers used to be – and I was ready to go.

Brompton C Line charging

Before my first ride I wanted to make sure the battery was full. Opening the connection port and plugging the charger in was a little fiddly. And on a couple of occasions when I plugged the charger in I’d get a red light rather than the green that denotes charging. I found it was most often successful when I plugged the battery into the charger, then the charger into the wall, then switched the wall plug on.

Once charged and clipped onto the bike, the battery automatically powers up and the control panel lights up. It’s one of the simplest I’ve seen and is pretty foolproof to use. A long press powers the unit on and off; shorter presses cycle through the three power modes. To the left of the main power button is the button for the integrated dual-power front and rear lights. Cycle beyond max power on the main button and you enter a useful mode with no pedal assist but with power for the lights. I found that extremely helpful on longer rides after dark where I was low on battery but needed to conserve some juice to keep the lights on. There’s also a five-stage battery indicator here too.

Brompton C Line performance

On my first ride I immediately remembered that unique feel of a Brompton. Such a low centre of gravity takes some getting used to – particularly if you’re used to larger 700c or 29in wheeled bikes. There you tend to feel perched on the machine; here you’re really sitting ‘in’ it. That tends to have two oddly competing effects. On the one hand it gives you the feeling of stability; on the other it makes the bike feel quite twitchy. That twitchiness is amplified if you’re riding on rough roads – those 16in wheels do not like potholes in the slightest.

Still, that’s part of the Brompton character – electric or otherwise. Where these new C Line Explore Bromptons shine is that 250w motor built into the front hub. All three stages of power assist are immediate and noticeable. And even the lightest one improves stability by helping the front wheel to grip the road. So with 12 speeds and three pedal assist modes at my fingertips, I had plenty of ways to add nuance to my ride. After I got used to the unusual shifting (on both the four-speed derailleur shifter and three-speed hub shifter, you tap inwards to go up a gear and outwards to go down), it quickly became easy to find the right gear to complement the gradient and pedal assist.

Brompton C Line pedal assist

One of the first things I noticed was the motor assist cutting out quite frequently. At first I though I had a faulty unit. But looking at the speedometer on my watch I realised I was hitting the 15mph / 25kph threshold (beyond which e-bikes aren’t allowed to give pedal assist) much earlier and more frequently than I’d realised.

And that’s the bottom line with the Brompton C Line Explore 12-Speed: this thing flies! Acceleration from a standing start can give you quite a kick if you’re on level 3 (it feels more gradual on the lower levels). And once you’re up to speed it has the effect of flattened low inclines completely. With steeper hills you need to be a bit more selective where gears are concerned. If you’re in a low enough gear it’ll glide up a 15% gradient. Get the gearing too high and you’ll obviously need to put a bit more work in. Get it right, though, and you might find yourself (like I did) embarrassing a few lycra-clad warriors testing themselves on hilly parcours.

Gear changes were nice and smooth, except when climbing. When putting power through the pedals, the shifters sometimes struggled. When that happened I’d need to stop pedalling to make the shift – which could make me lose momentum. Once you get your head around this, it just takes a different mindset to shift down before steep gradients. And I’d try to do that on a road bike anyway.

Brompton C Line ergonomics

One thing I did struggle with was cycling through the power modes. Because Brompton has gone with a front pannier mount for its battery and control panel, it’s not at the optimum height for regular operation (at least not for me). I felt I had to lean forward a little too much to change settings. Again that’s made awkward because of those twitchy wheels. So I found I would tend to stay in a single power setting for most rides. And I’d decide on the setting based on the length and difficulty of the route, maybe cycling up to the top power level for steeper inclines then reducing power at the summit.

In terms of ranges, Brompton says the battery will last from 20-45 miles (32-72km), depending on terrain and power level. So I was expecting to get around 20 miles out of the battery at full power and up to 45 miles on low power. Although it’s hard to find much flat terrain where I live in the southwest of England, my test rides seemed to bear this out. At full power my battery was dropping one of its five bars every 4.3 miles (7km) – so lasting about 21.7 miles (35km). On lowest power it dropped one bar every 8 miles (13km) – so going around 40.3 miles (65km) on a single charge. That’s a little less than the stated 45 miles, but I’d put that down to the lumpy terrain.

Brompton C Line range

I’d notice those figures dropping a little when using the lights but only but around 15%. I’m not sure I’d chose to ride a Brompton if I were riding unbroken distances of 40 miles plus, but I’d happily take it on 10 to 15-mile commutes to the office and back, knowing a full charge would get me home. Given that the charger is pretty cumbersome, I wouldn’t want to carry it in a backpack. There’s no rear pannier rack on this model for extra gear (you’d need the Roller Frame version) and there’s only room for a lock or smaller accessories in the front pocket of the battery case.

As always with Bromptons, the frame feels sturdy even with that hinge on the downtube. And the components feel top notch. There’s a high handlebar option for taller riders (which is useful as there’s only one frame size). There are eight models in the range overall – four with the steel frame I tested (C Line) and four with steel and titanium frames (the more expensive P Line). Each line has Urban 4-speed and Explore 12-speed models and versions with roller frames – four-wheeled rear pannier racks that makes wheeling the folded bike around a lot easier. The C Line goes from £2,900 to £3,230; the P Line from £3,695 to £3,985.

Should you buy the Brompton C Line Explore 12-Speed?

Despite looking the same as Brompton designs of 20 years ago, today’s experience is much smoother and – in my opinion – more enjoyable. I feel the Brompton’s unique design is just made to be an e-bike. It excels on short urban trips, with smooth pedal assist that allows you to enjoy all the benefits of cycling (exercise, fresh air, escapism) while minimising the downsides (hills – that’s all I’ve got).

Yes the folding mechanism can take a little getting used to, as can the low centre of gravity and the reach for the control panel. But with 12 gears, up to 45-mile range and one of the smoothest pedal assists I’ve come across, it’s one of the best excuses I’ve found in recent years to just get out and ride whenever I can. It’s not a bike I’d recommend for day-long rides, but I don’t think it was designed with that in mind. But as a regular low-mileage workhorse, it’s a real pleasure to use.

Brompton C Line 12-Speed Explore technical specs

Frame	Steel
Motor	250w hub motor
Battery	Brompton Electric 300wh lithium-ion battery (2.9kg / 6.3lb inc bag)
Weight	From 17.3kg (38.1lb)
Wheels and tyres	16in wheels; 349 x 35c tyres
Colors	12 colors available

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