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rogerzilla
Legendary Member
Yes, it's mainly to tidy the chain when the bike is folded, and the derailleur function is a srcondary feature. If you add more chain, the arm will run out of travel and the chain will flop about after folding the bike.
steveindenmark
Legendary Member
Its a clever design. If only they would sort out the plastic gear levers and awful pedals.
Thanks for that , reason I ask is I've put a smaller chain ring on
This should help you to know the size you should have: Brompton chain length chart.
I swapped out the 50 for a 44 on my Brompton. Ran it for a while with the standard chain to see how I got on with it. The chain pensioner took up the slack and there were no issues with it at all. I did eventually remove a couple of links when I decided to keep the 44 on permanently.
pedals easily changed, how many bikes come with those awful plastic pedals, reflectors and a packet of toe straps..... premium bikes no pedals at all.
FrankCrank
Old layabout
If you can afford a couple of grand or so , you can get a CHPT3 Brommie, which comes without mudguards. It does have some titanium parts though, but mudguards just wouldn't do for a collaboration with a TDF stage winner. Wonder if they'll follow this up with a folding TDF type bike. A cynic might say that the way Brommie prices are going, they'll soon cost as much as a TDF bike, but of course, I'm not a cynic 
rualexander
Legendary Member
You are talking about the chain tensioner I think, not the derailleur.
some ridiculous prices on flea bay, £2500 for a black edition, over 3k for a used older model Chpt3 or even £5500 for the new Chpt3 !!!!! Standard Bromptons asking a high price too.
Last edited:
Kell
Veteran
- Location
- High Wycombe/London
It's mostly because what looks like the derailleur isn't really a derailleur. It's a chain tensioner.
The job of actually changing the cogs at the back is done by a chain pusher. If it didn't fold, the one-speed and three-speed versions wouldn't need it at all because the chain doesn't move cogs.
I've just filled in another Brompton survey and reading between the lines, even with the prices they charge, I think they're looking at moving manufacturing 'offshore' somewhere.
Pretty sure that the last three surveys I've filled in have mentioned something like: How important is to you that the Brompton is built in the UK? And then in another question: Are you prepared to pay more for goods made in the UK?
It's mostly because what looks like the derailleur isn't really a derailleur. It's a chain tensioner.
The job of actually changing the cogs at the back is done by a chain pusher. If it didn't fold, the one-speed and three-speed versions wouldn't need it at all because the chain doesn't move cogs.
Thanks I've now realized that took a few links out and Bingo , sweet
I've just filled in another Brompton survey and reading between the lines, even with the prices they charge, I think they're looking at moving manufacturing 'offshore' somewhere.
Pretty sure that the last three surveys I've filled in have mentioned something like: How important is to you that the Brompton is built in the UK? And then in another question: Are you prepared to pay more for goods made in the UK?
