What type of chain should I buy for my Brompton bicycle?

The chain on my Brompton bicycle is stretched, and I would like to buy a replacement. There is no Brompton dealer in my country, so I'd like to just go to a bike shop and purchase a new chain, but I'm not sure which chain I should ask for that will "fit" the brompton.

What type of chain should I buy to replace my brompton's old chain?

  • Please answer this question in general (for all Brompton models) so it can help any Brompton owner (not just me) determine which chain they can buy that will work for their bicycle. Apr 18, 2023 at 19:21
  • The answer will almost certainly be along the lines of "count your sprockets" because Bromptons have been sold with several gear configurations including internally geared hubs
    – Chris H
    Apr 18, 2023 at 19:25
  • 1
    See also the Brompton "ds-chain" Data Sheet trade.brompton.com/Uploads/QPart/QPart-Datasheets/ds-chain.pdf Apr 18, 2023 at 19:29

1 Answer 1


Bromptons use 3/32" chain which is (or was) the standard derailleur chain, even if your Brompton doesn't have derailleur gears.

When buying a replacement chain, pick a 7/8 speed one. The 9-speed, 10-speed and 11-speed ones are too narrow.

However, pre-2011 Bromptons may use a different chain.

New Bromptons use the 3/32" chain for 3-speed systems too that only have internal gear hubs. So unlike all other bikes that have a different chain width for derailleur and non-derailleur systems, Bromptons always use the derailleur chain.

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