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Brompton folding bikes offer things most folding bikes don’t, albeit at a price.
The quality is unsurpassable, and they fold down to a size more compact than any other folding bike.
This article reviews the Brompton M6L folding bike, which offers all the above and more.
Note: the M6L also exists as an electric bike and in a “Superlight” part-titanium version that weighs only 24.9 lbs.
- Frame material: Steel
- Gears: 6 (standard range)
- Brakes: Dual-pivot caliper brakes
- Folded size: 25.3″ x 23″ x 10.6″
- Weight: 26.7 lbs. (12.14 kg)
- Load capacity: 242 lbs.
- Wheels: 16” with double-wall 28H rims
Who The Brompton M6L Is Aimed At
The Brompton M6L is marketed by its maker as an all-rounder aimed at commuters or anyone who wants a bike for jaunts into the countryside.
This bike is great for vacations and days out because you can pop it in a trunk and still have room for loads more stuff. You can also fit Bromptons into standard-sized suitcases or put them into overhead plane lockers (airline dependent).
A key specification of the M6L is the fenders, denoted by the “L” in the name. These automatically make the bike suitable for all-weather riders such as bike commuters.
Although the standard Brompton M6L is affordable compared to other Bromptons, it’s still expensive to most people. A typical buyer either finds the British £1265 price tag negligible, or they’ll be willing to stretch for the artisanship.
Brompton bikes aren’t usually made from expensive materials, but the expertly brazed high tensile steel frames are durable, compliant, and beautifully built. Brompton brazers undergo a rigorous 18-month training process.
You’ll love this bike if you need the compact folded size and/or if you value attention to detail. If weight is a priority, you can buy lighter for much less money.
Top Features Of The Brompton M6L
Below, we delve into the finer details of the Brompton M6L.
Brompton uses high-tensile steel to make most of its frames. This surprises some people, as it’s not an expensive material and adds to the bike’s weight.
However, steel is strong, durable, and naturally more compliant than aluminum, though not as compliant as thinner Chromoly tubing. Brompton uses titanium to make lighter and potentially more compliant bikes (e.g., the M6L Superlight).
The frame, forks, and Brompton standard seatpost are all made of steel, and this helps the ride quality at the expense of weight.
Between The Main & Rear Frames
The smoothness of the ride is also assisted by a polyurethane suspension block that Brompton mounts between the main and rear sections of frame. These come in various degrees of firmness, and according to your weight make a difference to comfort.
Video: Adjusting & Replacing A Brompton Suspension Block
Brompton 16” Wheels & Tires
Brompton bikes famously use 16” wheels only. This, together with their efficient folding method, is what makes the folded size so small.
Later models of the Brompton M6L are fitted with Schwalbe Marathon Racer tires. One good thing about expensive bikes is that you don’t usually get poor tires.
Schwalbe’s Marathon Racer tires are lighter than their robust Marathon and Marathon Plus stablemates, though not necessarily faster rolling. Either way, you’re unlikely to need a hasty change of tires. They’re above average.
Read more: Choosing tires for folding bikes
The M6L uses Brompton’s unique gear system comprising a 3-speed Sturmey Archer hub and 2-speed rear derailleur for 6 speeds overall. It doesn’t have Brompton’s wide-range (BWR) hub, so you get the standard 219% range rather than 302%.
To simplify the above, you are genuinely getting a 6-speed bike instead of the equivalent of an 8-speed that BWR Bromptons offer. Note you can also order Bromptons with a smaller 44t chainring, which reduces the whole range by 12%.
What else does the “standard” 6-gear range mean? On a Brompton, it means that three lower gears are dovetailed onto their standard 3-gear range. This adds a lot of versatility, especially for riders in hilly areas.
In comparison to a Brompton with a BWR gear range, the M6L’s gears are squeezed at both ends. The easiest gear isn’t quite as easy for hills, and there’s less resistance for strong riders who want to pedal hard on descents or flat roads.
Switching chainrings is a way to adapt the bike to your needs, whether you want easier or harder gears. As it stands, this is more a bike for steady riding over moderately undulating or flat terrain.
A nice benefit of the internal gear hub is that you can change gear when stationary. This is highly inadvisable with derailleur gears.
Handlebar & Saddle Height
The handlebar of a Brompton is always significant because it gives you a clue as to the manufacturer’s intent. The M6L comes with Brompton’s M-type handlebar. This is a handlebar with significant rise as compared to the sportier S-type.
Note that if you want this bike with a different handlebar, you need to look at S6L or H6L models instead. These have Brompton’s low S-type handlebar and high H-type handlebar, respectively.
A relaxed riding position is promoted by the M-type Brompton bar. It’s intended for casual riding or some mild fitness riding if you want to ramp up the cadence.
The Brompton M6L has an extended seatpost, too, making it suitable for riders with an inside leg measurement up to 35”. Thus, it accommodates riders well over 6’ tall.
Battery Lighting Kit
A nice feature of the Brompton M6L is the battery lighting kit, which also nudges it towards bike commuters. This includes a removable 400V USB rechargeable Cateye headlamp and a standard Brompton battery-operated rear light.
Aside from the aforementioned fenders with mudflaps, you also get a pump (with the standard M6L), a front carrier block for attaching bags, and pedals—one foldable and one standard flat aluminum.
Opinions about the Brompton M6L on social media are positive. This is a bike that’s not easy to dislike according to our research. Below, a satisfied M6L commuter shares a photo on Reddit.
Brompton M6L Alternatives
It’s natural to look at alternatives before any purchase, so below we show you three alternatives to the Brompton M6L.
1. Brompton C-Line Explore Folding Bike
If you have trouble sourcing a Brompton M6L, know that the Brompton C-Line Explore is its successor. So, what are the differences? For a start, it’s a little more expensive than the basic M6L model, the price being the main downside of all Bromptons.
On a Brompton C-Line Explore, you get the BWR hub as standard, so you have a significantly wider range of gears than you’d get on an M6L (302% vs 219%). That affects both ends of the range, meaning you can climb a little easier and ride faster.
The C-Line Explore is available with a Low, Mid, or High handlebar depending on how tall you are and how you like to ride your bike. From the M6L generation, you’d need to choose the S6L for the Low handlebar or H6L for the High bar.
What We Like
- Artisanship – Brompton bike builders are artisans working in London.
- Gears – the C-Line has a wider gear range than the M6L.
- Extras – Presta/Schrader pump, 500-lumen front light, carrier block.
What We Don’t Like
- Price – not for tight budgets.
2. Dahon Mariner D8 Folding Bike
One of Brompton’s leading competitors is Dahon, and the Mariner D8 is their most popular bike. It’s a little more affordable than a Brompton, but the price still isn’t trivial to most mere mortals. There are many differences between this and the M6L.
The aluminum frame of the Dahon Mariner makes it a different bike from any Brompton. Extra features like a kickstand and rear rack bump the weight to 27.69 lbs., so the Dahon is heavier. The steel frame of a Brompton is inherently more durable.
Gearing on the Mariner D8 is more versatile than that of the M6L. Its 8 gears include an 11-32t cassette at the rear and a 53t chainring at the front. It has a gear range of around 290% versus the 219% of the M6L, with a lower lowest gear and a higher highest gear.
What We Like
- Refined – Dahon bikes are full of patented technologies and design evolution.
- Gears – has a wider, more versatile gear range than the M6L.
- Cargo – the inclusion of a rack makes this a promising commuter bike.
- Forks – steel fork blades add compliance to the ride.
What We Don’t Like
- Durability – the steel construction of a Brompton makes it more durable and adds to its resale value (as does the iconic name).
3. Schwinn Loop 20” Folding Bike
If a limited budget prevents you from even thinking about a Brompton, you might consider the dependable Schwinn Loop 20” Folding Bike. You can buy decent folding bikes for even less money, but this is a good sub-$500 pick.
An obvious downside of the Loop versus the Brompton M6L is the weight at 34 lbs. That’s over 7 lbs. heavier, which isn’t a piffling amount. Some of that weight, though, comes from an integral rear cargo rack, which the M6L lacks (you can add one).
A big difference between this bike and the M6L is the extremely easy gear range of the Loop. The latter has a 215% range with a small 40t chainring and 13-28t freewheel that limits the bike to very casual flat riding or ardent hill climbing.
What We Like
- Price – an eye-catching, well-specified bike for the price.
- Easy-mount – the low frame is ideal for anyone with joint or flexibility problems.
- Cargo – includes a robust, integral cargo rack.
What We Don’t Like
- Gearing – the easy gears on this bike might be ideal if you live among hills or are a leisurely rider, but some will find them too low.
Conclusion: Is The Brompton M6L Any Good?
What We Like
- Artisanship – you pay for attention to detail & finely honed workmanship.
- Material – steel is more durable and repairable than aluminum.
- Compact – folds to Brompton’s unrivaled 25.3″ x 23″ x 10.6″ folded size.
- Hub – the Sturmey Archer gear hub lets you change gears when stationary.
What We Don’t Like
- Gear range – the standard 6-gear range is useful but more limiting than bikes with the BWR hub.
- Price – don’t buy it if it puts you into financial strife.
The Brompton M6L is certainly a good bike for the money, as long as the money doesn’t put you into the red. It’s lightweight, durable, and beautifully constructed.
Check out the Brompton M6L Black Edition here.
(The Chromoly steel frame spec listed by Rei should be treated with caution as Brompton does not usually make Chromoly frames. Original specs do not mention it.)
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