When I saw an Alfine 11 hub online for less than half price, I couldn’t resist. I had hoped to do an Alfine 11 Brompton conversion at some point, and the opportunity to buy a cheaper Brompton through cycle-to-work brought hub and bike together. I used the bike as a commuter for 18 months, getting used to the Brompton 6-speed set-up.

I knew that Bromptons had been converted to Alfine 11 hubs by others, but in one case with a seriously modified rear triangle. Perhaps that should have been a warning sign. My Alfine 8 conversions had gone like a dream, and I hadn’t anticipated that the 11 would be much different.

So I set about working out my gear ratios using the magnificent Brompton Gear Calculator coming up with an ideal spread (for me) using a 16T rear sprocket, and a 40T front chainwheel – made by Stronglight, but Brompton compatible.

For the Alfine hubs, the over-locknut width between the rear dropouts has to be stretched to accommodate 135mm (a Brompton is about 120mm), and this requires stretching the forks to about 155mm so they spring back to the width you need.  For this purpose I used an old wheel axle, tensioning with the bearing cones, some big strong washers, and rubber washers against the frame to avoid taking the paint off the bike. I seated the ends of the axle through the circular holes in the dropout sections – not in the dropouts themselves. This meant the axle couldn’t suddenly spring out, and I was less likely to bend the dropouts. It worked fine – a bit nerve-wracking as I approached the 155mm point – and I wore safety glasses throughout. I’ve been advised this procedure is risky on an older Brompton – the frame could simply crack.

So far, so good. The new wheel dropped into place beautifully. But to cut a long story short, I came across three major obstacles to completing the Alfine 11 conversion:

  1. The guide arm that takes the incoming gear cable is longer than on the Alfine 8 – it fouls the fold (specifically the hook on the front-wheel.)
  2. This longer guide arm also fouls the chain-tensioner. I tried a number of different angle options for the long-arm, using the various Shimano and Sturmey no-turn washers, even thinking about bringing in the gear cable from the rear. No doubt there will be a solution for those skilled with bending and shaping metal, but this was beyond me.
  3. The Alfine 11 gear triggers are larger than the Alfine 8’s. As a result they don’t sit easily on the handlebar of an M-type Brompton. There isn’t enough space left for your hand! For me this was really the last straw. Short of converting my Brompton to an S-type (flat bar – would require a whole new stem!), this was a compromise I couldn’t live with.

So my sad half-finished Brompton sat on the floor of my study for over a year.

Sometimes it’s good to walk away from a project, and come back to it later.

With a year’s reflection, the solution became obvious. I would give my ‘big’ commuter bike the present of a new Alfine 11 hub, and give my Brompton the 10-year-old Alfine 8 I have on my commuter. I had just had the latter serviced, so it seemed to make sense. So over a few days, I stripped the spokes from the Alfine 8, then reassembled the wheel around the Alfine 11.

Apart from seriously encrusted salt beneath the rim tape, I was  amazed at the good condition of the Alexrims rim on my 10 year old (10k miles+) commuter. (Ridgeback Nemesis) The Alfine 11 turned out to be a surprise Christmas present, and is running like a well-oiled machine (funny that!).

And what of the Brompton? I’ve done Alfine 8 conversions on a Brompton before – but never on my own Brompton. I have to say, this is a total delight: easily enough installed (there are some tips and tricks I will try to cover elsewhere) and for the first time I’m riding a quiet Brompton, with crisp gear changes. The Sturmey 8 I have on my vintage Brompton sounds like a hive of bees by comparison.

I’m very happy to have given up on my Alfine 11 conversion. Sometimes the best way forward is back.

And here’s the final result on the Brompton: hopefully another ten year’s use out of this old hub: 




  • dunxmac

    Hi, I used the tensioner from the 2-speed Brompton – the arms are slightly longer. I removed the chunky jockey wheels that are designed to slide left and right, and set the standard (1-speed) jockey wheels bolted with a longish bolt to sit on the outside ends of what had been the slider axles. There is a section on the back of the 2-speed tensioner that juts out – I had to saw this off, flush with the rest of the back to make it fit (not difficult). I found that with the 16t sprocket dished outwards (it doesn’t work inwards) by a happy co-incidence the jockey wheels line up with the sprocket, and you don’t have to fine-tune the alignment of the jockey wheels with the sprocket using extra washers. The 16t sprocket is just small enough to enable the jockey wheel on the short arm of the tensioner to clear the sprocket. No tensioner extensions required! I’ve had this setup for over 2 years now, and it has been wholly reliable and maintenance free. The one thing to avoid is sudden backpedalling, which can knock your chain off – that’s just a learning thing – after a while you learn not to do it. It may be a sign that my chain is not as aligned as I think it is, but I can live with that!
    I did this same conversion on my son’s Brompton – he has big strong legs and wanted a 54t at the front – which works fine. I like lower gears overall, so I have 44t on the front with the 16t rear.

    See more here: https://www.bromptongeek.com/index.php/2017/09/29/which-8-speed-hub-is-best-for-my-brompton/

  • Gilles

    > I’ve done Alfine 8 conversions on a Brompton before – but never on my own Brompton. I have to say, this is a total delight: easily enough installed (there are some tips and tricks I will try to cover elsewhere)

    Before cold setting a Brompton to fit a Nexus/Alfine 8, I’m interested in any feeback you might have. Thank you.

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