Brompton G Line with Roller Frame 8-speed

The Brompton G Line is described on the company’s website as the ‘first ever Brompton with the ride feel of a full-size bike’, and that’s largely true: this is an easy-to-ride bike that’s very capable on a range of surfaces, and folds down into a very neat package for multi-mode travel. You genuinely can go off and do adventures on this thing, and you’ll have fun, although they won’t be your quickest adventures ever.

> Buy now: Brompton G Line with Roller Frame for £2,499 from Brompton

Unless you’ve been living under a rock for the last 50 years you’ll probably be aware of the Brompton, which with its 16-inch wheels and brilliantly simple fold is one of the most recognisable and popular folding bikes in the world. The G Line is the first Brompton that moves away from that wheel size.

With its 20-inch wheels, big-chamber Schwalbe G-One Allround tyres, hydraulic disc brakes and Alfine 8-speed hub gear, it’s very much been marketed as a go-on-adventures bike – lots of social videos of the bike in kayaks and up mountains, that kind of thing. We’ll get to all of that, but personally I think it’s a bit of a smokescreen for something that Brompton has probably wanted to make for a while, which is just: a bigger bike.

Brompton G Line: Ride

I’ll be upfront here – I don’t get on all that well with ‘normal’ Bromptons. This is because I’m a big rider, tall (1.89m) and heavy (100kg), and the one-size-fits-all geometry just doesn’t work all that well at my end of the bell curve. I can ride a Brompton fine, but it’s not that enjoyable. (It’s not me in the pics, by the way, that’s Stu.)

The G Line is much, much better. You’re still getting the same UK-built hand-brazed steel frame, and the excellent fold, and the attention to detail, but in a significantly bigger package. The bike has a longer reach, and a longer wheelbase, and position-wise it just feels more like a normal bike. The three sizes – S, M, L – all use the same frame but swap out seatposts and handlebar components to offer a bit more room the bigger you go.

The change is most noticeable when you’re standing up out of the saddle on a steep climb. Standing up on a 16in-wheeled Brompton isn’t that much fun, or even that effective – the bike doesn’t respond well to the change in weight distribution and I always felt a bit vulnerable. The first time I tried it on the G Line was a revelation, because it just feels completely normal. 

In fact, the bike feels entirely normal for 90 per cent of the time you’re riding it. There are some things it doesn’t do all that well (more on that in a bit) but if you’re mostly riding the bike on decent surfaces and occasionally hitting rougher terrain then there’s a lot to like about the ride.

It’s very composed, and the combination of big tyres and the elastomer in the rear make it pretty comfortable too. This isn’t the kind of bike you tear down descents on, or lean hard into corners, but I never really got myself into trouble, even off-road. The hydraulic disc brakes are certainly a boon when it comes to scrubbing off some speed.

We’ve talked about standing up and I found myself doing that a fair bit, because for me the bike is a bit overgeared. The Shimano Alfine 8-speed hub gear is an excellent unit, but the 306% range isn’t enormous; a 1x setup with an 11-42T cassette is about 380%, and a 50/34 double with an 11-34T cassette is over 450%. That means there’s some compromise in terms of where to put the gears, and Brompton has opted for a 54-tooth chainring and 20-tooth sprocket, which gives an effective range of 28.9 to 88.5 in old-fashioned gear inches, or 2.31m to 7.06m of development.

Those numbers may or may not mean anything to you, but the lowest gear isn’t all that low; my standard single-ring gravel bike is about 15 per cent lower at the bottom end, and even that’s not geared especially spinny. Of course, if you move the goalposts then all the gears shift, and the top gear isn’t especially high either, but that was less of an issue for me. If I were to buy one of these, I’d probably swap out the chainring for something a bit smaller. I am a big lad, though.

I found most of this out – or was found out, depending on how you look at it – on one of my main testing rides, which was an attempted 200km audax where we caught the train down to Southampton and rode back in the direction of Bath, over a variety of surfaces. About half of it was unsurfaced, and some of it was very slow going. There’s a write-up of the ride here, but the TL;DR is that I was cooked by the time we got to Shaftesbury, 130km in, and I limped back to Warminster and got on the train the rest of the way. A 160km day in total.

The reason I didn’t finish was entirely down to the fact that I’d bitten off more than I could chew. Had I done the route on my ‘normal’ gravel bike (a Cannondale Topstone Carbon), I reckon I would have been okay, just about. And if I’d trained it down to the coast and ridden the Brompton back on the tarmac that would likely have been successful too. But the combination of Brompton and gravel was just a bit much that day, and even if I hadn’t run out of puff we probably would have run out of time.

Why? Well, the Brompton G Line isn’t quick. It’s very well built and easy to ride, but it’s still a 15kg bike with a hub gear and small wheels and big tyres. You can’t go as fast as you do on your fancy-pants lightweight 700C derailleur-geared bike for the same effort – that’s just physics.

For a lot of the bikepacking and touring that Brompton is suggesting this bike would be good for, that’s not a problem, because you’re unlikely to be attempting to knock out a big ride against a deadline. But still, it’s worth knowing. Smaller-wheeled Bromptons can be pretty light and nippy: for the same money as the G Line you can have a sub-10kg P Line and those things go like stink. You need to adjust your filter here.

> Buyer’s Guide: Best folding bikes — portable bikes for convenient commuting

Also, small wheels have their limits off-road. I’ll preface this by saying I was genuinely impressed by how well the G Line handles once you leave the tarmac. Our audax ride had a bit of everything – well-graded railway paths, sandy New Forest heathland, rocky bridleways, even a mountain bike trail with North Shore-style wooden boards – and it coped admirably. I was only actually defeated twice: once on some hateful climb somewhere near Blandford Forum that a kind farmer had helpfully resurfaced with golf ball-sized rocks so he could get his excavator up and down it. And once on Gold Hill in Shaftesbury, where the combination of an overgeared bike, small wheels and lumpy cobbles was enough to force me into walk mode near the top.

Everything else was rideable, but not everything else was fun. Sand is especially bad on small wheels, which dig in and rob you of all your speed, and there was a lot of that in the first few hours of the ride. All of which is to say: if you want to go out and do adventures, you definitely can. But some bits might be tough.

Brompton G Line: Load & fold

Talking of adventures, the G Line is set up to take plenty of luggage. Our test bike came with the roller frame, which both gives you somewhere to hang your panniers and also lets you push the bike around easily once it’s folded.

Folding the G Line is as easy as folding any other Brompton, which is to say it’s important to learn how to do the things in the right order, but once you’ve got that dialled it genuinely takes seconds. It folds to 28.3 x 26.2 x 16in (72 x 67 x 41cm), compared with 25.3 x 23 x 10.6in for the P Line.

I actually found it easier than a standard Brompton, firstly because it’s a bit bigger, and secondly because the frame and steerer clamps are a better design and locate in place more easily. One thing to note, though, is that it’s not especially stable – it’ll sit fine on its wheels, but there’s more weight on the handlebar side and it wants to fall that way. Also, be careful you pay attention on sloped railway platforms in case the bike just rolls off towards the tracks and an oncoming train. Just saying.

I fitted panniers just to prove I could, but mostly I used an ancient AGU rack-top bag that was a good fit for the rear rack and held enough stuff for a day ride. You have to take that off before you fold the bike, obviously, and the same for panniers. The bike can also be used with Brompton’s front-mounted bags, and there are some specific G Line ones available.

If you’re on a long ride you’re going to need fluids, and the G Line helpfully has two sets of bottle cage mounts. There’s one on the inside of the stem, which is the one I used because it’s easy to access. The alloy fork has another set on one side (the side facing out when it’s folded) and you could use that for a second bottle or for more luggage space.

Given that it’s not a big bike you can fit plenty of stuff on it in a variety of ways: the flat handlebar would take a small bar roll, and you could fit a big seatpack.

Brompton G Line: Tour de force

Would I use it for a loaded tour? I can definitely see the appeal, especially if you’re planning a tour that involves trains. Let’s be honest, travelling with any bike on any UK train is an enormous ball-ache, and travelling with a loaded bike just makes it worse. I love the fact that the G Line is capable enough to take all your luggage, nice to ride, and still folds up small enough that you can give your local Train Operating Company two fingers and get on whatever service you fancy.

Or you could even head over to the continent: taking it on the tube to St Pancras is no problem, and neither is the Eurostar (although you will need a bag for it). So long as you’re in no hurry to get home again, it’s a great companion.

If your ambitions are more modest, it’s a great bike for year-round commuting. Stick it in the car boot or roll it onto the train and it’s not going to let you down. The low-maintenance drivetrain and full mudguards mean it’s set up to cope with all the weather, and the big tyres will be welcome if your urban roads are anything like ours.

Check out our guide to the best bikes for commuting, for more options.

Brompton G Line: Value and conclusion

At £2,499 it’s not cheap, but in terms of the Brompton range it’s very much in the middle. You can spend over four grand on a sub-8kg T Line Ultralight, and even a no-frills A Line is a grand these days. If I was going to buy a Brompton, it’s the Brompton I’d buy. I like the ride and the versatility of the bigger wheels and frame, I prefer the dependable hub gear and disc brakes over the more esoteric options on the 16-inch bikes, and I don’t need the more compact fold.

There’s really not a lot to directly compare it with either, in terms of similar bikes. We reviewed the Birdy Touring a few years back, a similarly priced folder with a touring bent, but that’s about where the similarities end. As much as any bike is unique, you’d probably say this Brompton is: a gravel-orientated touring folder? I’m in.

> Buy now: Brompton G Line with Roller Frame for £2,499 from Brompton

Verdict

A bigger Brompton that’s great for anything from commuting to multi-day adventures

All the deals displayed on our review pages are pulled from a constantly updating database feed of the best affiliate deals available. The criteria for deciding on what are the best deals is who is offering the lowest, delivered price. In most cases we will be showing the very best deal available online, but sometimes you may be able to find an item cheaper. If you can please feel free to post a link in the comments box below. To find out more about affiliate links on road.cc click here.