Chain replacement for pre 2008 Brompton

[nigel8322]

I have a 2002 3-speed hub gear Brompton, bought second hand. The chain was badly worn so I tried to replace the chain and the sprocket. After much trawling of the 'net I spoke to Brompton via an online 'chat'. They confirmed that the 1/8" chain needed (without quicklinks, which make it too wide to fit) was no longer available. A 3/32" chain wouldn't fit on the chainwheel. They advised replacing the chainwheel, which also necessitated changing the bottom bracket. Including the chain and sprocket the price was around £150. In my bit box I found a Stronglight 80 two speed which gave a perfect chainline, using the large chainwheel only. Problem solved for the price of a 3/32" chain and sprocket. Other owners of pre 2008 Bromptons may be able to use this to save money and the planet's resources.

[Ugly]

I ha a similar age Brompton. A 13 tooth sprocket is £6 from St John St Cycles an 1/8'' chain about £15 from the same. I never had a problem with a spring link or a more modern quick link, if you do just join the chain with a chain rivet tool these are not expensive and tools are an investment. you were about to be ripped off big time!

[rogerzilla]

Cheeky! Just use any 1/8" chain as long as it doesn't have a 3-piece master link, which could get caught in the derailleur.

Also, if your FAG BB is worn out, they will tell you you need a new crankset too, because the 119mm ISO BB is no longer available. Use a 110mm JIS BB (I tried it with a Shimano UN55 and the chainline was exactly the same).

Also, a 3/32" chain has always fitted on a Brompton chainwheel. The derailleur bikes didn't gave a special chainwheel. The sprocket on a 3-speed usually needs a 1/8" chain, so maybe that's where the confusion comes from.

[nigel8322]

It looks as though Brompton may have used slightly different components on different versions. A 3/32" chain didn't fit onto the original chainwheel (I tried) and a 1/8" single speed chain with a quicklink fouled the chain tensioner (I tried that too). I didn't try SJS Cycles so they may have had a suitable chain, but it needed to be the sort where you joined it by the method suggested by rogerzilla (similar to how you used to join Shimano chains). I may have limited my options by specifying single-speed chains rather than any chain up to 8 speed, which might have been a fraction narrower? Thanks for the comments. I should have come to the forum for advice first, but at least my solution worked and was cheap!