Rohloff Brompton Kit


It took some figuring out, but I’ve got a Rohloff 14-speed hub gear conversion working happily on the Brompton 😉

The gear range with 13t rear cog and 54t front chainring – both completely standard – is 19” to 102” (1.54m to 8.11m). That’s a very wide gear range, as wide as a touring or mountain bike, with a low enough bottom gear for almost any hill – and being a sealed hub gear you can select any gear at any time with one twist of the shifter.

imageThe conversion involves fitting a complete new rear triangle, which I make in stainless steel. I make this triangle with or without an integral rear carrier as shown in these pictures.

Rohloff Brompton Kit using new steel triangle – £1795  
Rohloff Brompton Kit with integral rear rack – £1885

Want to add a rear disc brake? You can find them on the Disc Brake Page.

Don’t already have a Brompton? No problem, I can build you a complete new one – see the Rohloff Brompton Order Form.

Want to see some examples of Rohloff Bromptons I’ve built? Search the website for Rohloff Brompton.



Can this kit fit to any Brompton? Yes – the rear triangle I build will fit any Brompton made in at least the last 15 years. The kit replaces your entire gearing system, so it doesn’t matter what gears you have at the moment.

Does the bike fold as normal? Yes, with one exception – because of the wider back hub, the cranks won’t rotate all the way around when the bike is folded. The best trick is to put the cranks horizontally with the left pedal forwards, then fold as normal, this will put the pedals in the best position.

Does this make the folded size bigger? Yes, it makes it about 15mm wider – the exact amount varies a bit depending on what handlebars, shifters, brake levers and rear rack and other parts you have. The bike still fits into the original Brompton cardboard box, however.

How much weight does this add to the bike? It adds about 800g over the weight of the 3-speed Brompton.

Will the Rohloff shifter work with all handlebars? It will fit to all bars, but with the M- and H-type there isn’t much space left, so bar ends won’t work. There’s more space with the S-type and P-type.

Is the kit hard to fit? Not especially – the trickiest bit is removing your old rear triangle, the two pivot bolts can be quite solid. I do it with an impact driver, good long 4mm Allen keys usually manage, but occasionally the bolts have to be drilled out which means you need a new rear hinge kit. The rest is pretty simple – fit the new rear triangle, fit the rear wheel, mudguards and rack if you have them, fit the other parts and so the gear cables.

Can you fit the kit for me? Sure, no problem – there’s no charge for fitting if I do it here.

What’s the rear triangle made out of? It’s entirely stainless steel, brazed together. I use stainless because it’s tough – Brompton rear triangles get a lot of abuse, so a material that’s corrosion resistant is perfect.

Why don’t you use titanium? I looked into it – titanium is expensive to work with, and very difficult to repair. It would limit the designs I can make, and it can also have a limited lifespan. It didn’t seem worth it to save a few hundred grams when we’re putting a 1.6kg rear hub on the bike.

Does the rear triangle have to be painted? No – being entirely stainless steel, I can leave it as a brushed finish if you prefer.

What is the integral rear carrier? Normal Bromptons come in a couple of versions, the L-type with just mudguards or the R-type with an aluminium back rack as well. The kit I make works perfectly with these parts – you can still have just mudguards or the Brompton rear rack. However I also make a version with an integral carrier, made out of the same stainless steel as the rear triangle and permanently brazed on. It is lighter and stronger than the Brompton aluminium carrier.

Can it have a belt drive? Yes, this is possible, but with a limitation – there’s only one belt combination that works on the Brompton, 19/70, and that’s quite low geared, giving a bottom gear of about 17″ and a top gear of 88″.

What’s in the kit? The kit includes my new rear triangle in stainless steel, the Rohloff hub built into a rim, a chain tensioner, and the Rohloff rear shifter, cables and fittings. Depending on your Brompton, you might need a new chainset and/or chain, I can supply these if needed.

Fitting instructions for the Rohloff cables:

69 Replies to “Rohloff Brompton Kit”

  1. Ben,

    I just got back from San Francisco where I was visiting my sister and her new baby. I brought my Rohloff Brompton with me. I can confirm that the hills in SF live up to their legendary status.

    I thought you might be interested to know that my Rohloff Brompton could handle every hill I confronted in SF. Locals say you can go around the hills but I wanted to see if I could find a hill that I was not able to climb; but I I failed: every hill was climbable.

    I also rode the Rohloff Brompton on very steep dirt roads outside the city. I was with other people who had 21 geared mountain bicycles who were not able to make it up these steep dirt roads.

    The Rohloff Brompton you made for me has a 52 tooth chainwheel in the front and a 13 tooth sprocket in the rear. I live in London, which is quite flat, and – before this trip — I could never imagine using first gear. I was wrong. I used first gear often on my trip to California.

    Overall, I was very impressed with the Brompton Rohloff. Thank you for extending the range of the Brompton bicycle.

    Ay Clarke
    London, England

  2. Rohloff kit is nice, but why you still have use for chain tensioner.. There are solutions like horizontal sliding rear drop outs. The simpler The lighter The better

    1. The tensioner is needed because of the way the Brompton folds – the pivot is not concentric with the bottom bracket, so without a tensioner the chain would fall off when folding.

      1. Thanks for clarifying – so if I got a rear wheel puncture out on a ride the tensioner would still need the usual very precise/sensitive release and refit before and after the rear wheel is removed? Asking because it is quite a tricky job especially out on the roadside

  3. Can I order with a black hub? How long will it take the shipping? Do you have stock or do you have to build it? Thanks!

  4. Brompton changed their M and H bar/stem geometry recently, giving more room to fit brake levers, grips, etc. Does this make the combination of Rohloff twist grip and bar ends feasible on the new M-bars/H-bars?

      1. What’s the difference between the “new steel triangle” and “integral rear rack”?
        Still contemplating on this, delivery to Brunei?

        1. The kit includes a new stainless steel rear triangle. this can take a normal Brompton rack and mudguards, but additionally I make sa version with an integral rack that’s also made out to stainless steel and permanently brazed on.

          The integral rack is lighter and stronger than Brompton’s rack, but of course it cannot be removed.

  5. I originally ordered my Brompton with a -12% chain ring, will this work with the Rohloff speedhub ? Or do you recommend a different chain ring ?

    1. I normally use the 54t (+8%) with the Rohloff – the Rohloff is quite low-geared, so the 44t (-12%) might be a bit small.

  6. Hi Ben, I’ve been following your work for years already. Congrats for all amazing Bromptons delivered. I keep coming to your website as I’m intended to buy a Rohloff for my B some day.
    couple of questions I have since I think I may have saved enough for the shot:
    – Do you deliver to Switzerland?
    – assuming I’m a good owner and give it good maintenance, how many Km would it last?
    – Is it compatible with Oval chain ring? Is there any benefit from using it?

    Cheers ans kind regards

    1. Hi, no problem to ship to Switzerland, I do quite often.

      As far as I know, a Rohloff has never worn out! The oil should be changed approximately yearly, and after 5 years or so the oil seals might need a change, that’s an easy job. Apart from that, there’s very little that ever goes wrong with them.

      It depends how oval – the rear tensioner can take up some movement, but if it’s too oval it might cause problems when folding.

  7. Hi, if one goes for the rohloff hub and frame set will the old fork hook to the rear frame normally like with the old rear triangle?

    1. You can actually buy a Rohloff 😉

      The Kinderay looks interesting, and I’m very interested in trying one as soon as they’re available.

  8. Hi, with the rohloff kit is it possible to get the red hub and black spokes/rim? So that then the upgrades of the rear triangle in stainless and hub really pop on my black edition.

  9. Hi, do you have a close up picture for cable routing? I’m using dynamo hub with rear light. How can I run those cables?

    1. There’s two options – run it inside the chain stay like Brompton do, which works but is fiddly, or run it along with the brake or gear cables and then up.

  10. I have a P-handle Brompton. Will this work with it? Also, which shifter do you recommend? I like to look of CINQ shifter.

  11. Hello. If I decide to have the Rohloff (and I want one – I have one on my Thorn Sterling) I would want to bring it to you for installation. Is it possible to make an appointment for when I’m driving over from Spain and have it fitted so I can take it back with me?

    1. Sure – I’d need some time to make the kit first, but once I have the kit built for you then fitting only takes a couple of hours.

  12. Hi,
    Your kit looks great. We sold our Brompton 2 years ago to travel the world. Stuck in Vietnam due to what happened worldwide.
    But after when we can travel again, we would do with 2 Brompton. So we will need to get 2 new ones.
    If we decide to use your kit, should we order the most simple version like the M1L and then fit the kit we want? Or another version is better?

    1. Yes, the simplest Brompton is best, you’ll be replacing the whole transmission anyway so no point buying one with more gears.

  13. Hi,

    Will the Rohloff, Brompton with disc brakes fold to the same dimensions as the original?
    If not, what will the dimensions and weight be after the build?

    1. It depends on the rest of the specification, but a complete bike with Rohloff and disc brakes is around 13-13.5kg. The folded width is about 2-3 cm wider, depending on which handlebars you have, but it still fits the same boxes and bags.

  14. Hello – I’m considering purchasing a Rohloff retrofit kit (and maybe a whole new bike in addition). One thing I’m wondering is whether changing a flat tire, is the procedure for rear wheel removal & reinsertion the same as the standard procedure with the. OEM configuration?

    1. It’s similar, but even simpler – one Allen key skewer holds on both the tensioner and the wheel, so you just need an Allen key, no spanners.

  15. I am curious if you combine the rohloff conversion with an existing e-Brompton will you get additional speed or additional battery efficiency? Or both?

    1. It won’t have a direct effect on motor speed or range – what it will do is give you a wider range of gears, so you can go faster than the motor downhill, or have much lower gears to help with uphills.

  16. Ben,
    We bought a pair of Rohloff Bromptons from you and they have been fabulous. Under normal circumstances we do a lot of long distance cyclo-camping. But we also like getting into very remote areas of Scotland, the problem comes if I get carted off to hospital, it leaves my wife stuck with two large awkward items to transport and store, at a very stressful time. With the Rohloff Bromptons we can we can bale out in a taxi or a bus, easily, and not be restricted by hilly terrain. The Hope disc brakes are fabulous, great feel and stopping power. Your engineering has taken a London commuter bike and expanded it’s capability greatly. Thank you very much.

  17. A while back (2018) in these comments you expressed an interest in the Norwegian Kindernay hub. Have you been able to fit one to a Brompton yet?

    1. It uses a different rear triangle with removable sliding dropouts, a different tensioner, front and rear cogs, and the belt itself. It’s not an upgrade that can be added later, because it uses the different rear triangle.

      1. Thanks.

        Is it possible to have a front wheel (xx-406) with the Son delux dynamo built, together with the Edelux front light and rear LED dynamo light? What would be the price? There does not seem to be an option for this on the Rohloff Brompton Kit order form.

        Do the 406 rims come in black?

  18. Would the v-brakes from the stock brompton frame work? Or are disc brakes a must in this conversion?
    Like to know on the lead times to get one of these kit.

    1. The standard Brompton brakes (they’re actually callipers, not V-brakes) work with the standard 16″ (349) wheels, but if you’re also changing wheel size then disc brakes are needed.

  19. Hi Ben
    May I check what type of rim you build for Rohloff? Does the rim come with Rim brake with Rohloff QR Disc Hub for Rim/Disc dual use? and can it work with Gebra Rohbox


  20. Hello, I have a 2012 2spd Brompton (serial no 1201******), and the gears are a bit of a struggle. I plan to change the crankset for the current Brompton one (50t) and bottom bracket, and then fit your Rohloff 14-spd conversion later in the year. Are there any special requirements for this age of frame, or will everything fit as is?
    Many thanks

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