What are the exact specifications of the nuts used on the various axles of the Brompton bicycle?

Specifically, I have a 2016 M6R black, but I would appreciate it if you listed the specifications for all models for others as well.

I'm currently bikepacking through South Asia verrry far from a brompton shop. My axle nuts are rounding out, and I'd like to replace them and get some spares as well. Unfortunately, the local shops have nuts too small for my wrench and--worse--I don't know if the threading is slightly off from the axle.

This information was glaringly absent from the specification & schematic docs on the brompton website, but it does mention that the threading may be off between different rear axles, depending on the Sturmey Archer hub installed:

Can you please list the nut:

  1. nut size
  2. thread pitch
  3. flat-to-flat width (for wrench size)
  4. pitch-to-pitch width
  5. height
  6. anything else I should know to buy this nut from a third-party
  • Your best bet is to just go to a bike shop. They'll sell (or even give) you the right part, made from the right grade of steel, etc. It probably shouldn't matter that they're not a Brompton dealership. Aug 15, 2019 at 23:16
  • As mentioned in the original question, the local shops I went to don't have these nuts. I have to buy online.
    – qzcft
    Aug 18, 2019 at 12:12
  • No, the question just says that you're far from a Brompton dealership. Aug 18, 2019 at 14:06

1 Answer 1


Front wheel Axle Size is 5/16" - 26 tpi BSC Tpi = Threads per inch BSC = British standard Cycle

Rear axle seems to change depending on model and year of bike.

  • Hi, welcome to bicycles. Can you at least give the rear axle specs for the 2016 model being asked about?
    – DavidW
    Feb 18 at 3:19

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