Brompton chain standard..

[wafter]

I need to buy a more corrosion-resistant chain for the Brompton and wanted to check with the more learned that I'm getting the correct type.

I've been perusing this excellent resource and think I have it nailed, but wanted to be sure.

I frequently read that the Brompton chain is 3/32", apparently referring to the roller width that's universal on all 5-8sp chains. I've measured the width of the existing chain across the pins at 7.1mm; which suggests an 8sp chain. The SRAM quicklink on the current chain however states "7 speed".

It seems that 8sp chains are slightly narrower at 7.1mm than 7sp chains at 7.3mm, but the 8sp is backward compatable down to five speed.. and in any case mine measures as an 8sp even if the QL states 7sp (which I suspect may well be interchangeable too).

So.. can someone please confirm that the bike requires an 8sp chain..?

Ta

 

[Gunk]

8 speed Sram will fit, that’s what Warlands suggested and they’re a Brompton dealer

I use a PC830

 

[wafter]

Thanks - 8 speed it is then!

 

[mitchibob]

Thanks - 8 speed it is then!

I think I've used same a few times... three differences with Brompton SRAM chains.... the Brompton ones aren't as well lubricated on arrival, although, you'll have to clean fairly soon anyway. However, the Brompton ones, you don't have to lose a few links as can buy for your chainring. Plus, the Brompton ones never look as good as that other 8-speed, when clean. So, you'll have to make the right length, but then, keep have a few links to whack in your saddle bag for emergencies. Plus cheaper (damn, that's four differences)

Oh and feels like extravagance, but power link pliers are great (I put on wish list and had confused sister buy for me)

 

[Tenkaykev]

When I was " blinging " up my bike for the BWC I wanted to match the red/black colour scheme as much as possible. I fitted a KMC DMC 11 speed chain which I was advised wouldn't work. I adjusted the derailleur pusher screws and got it to shift successfully.

 

[12boy]

Since I have 3 or more sprocket wheels for both my Bromptons I use 10 speed chains which work fine on the chainrings. I did invest in a Park tools power link plier which I really like and is kinda necessary with a 10 speed chain. I also wax my chains instead of oiling them and have an old crockpot with a mix of canning wax, oil and othetb things which I heat till the wax is liquid and soak the chains for a while. The wax doesn't pick up grit like oil does.

 

[wafter]

I think I've used same a few times... three differences with Brompton SRAM chains.... the Brompton ones aren't as well lubricated on arrival, although, you'll have to clean fairly soon anyway. However, the Brompton ones, you don't have to lose a few links as can buy for your chainring. Plus, the Brompton ones never look as good as that other 8-speed, when clean. So, you'll have to make the right length, but then, keep have a few links to whack in your saddle bag for emergencies. Plus cheaper (damn, that's four differences)

Oh and feels like extravagance, but power link pliers are great (I put on wish list and had confused sister buy for me)

Thanks - appreciate you clarifying those differences! I've had good experiences with KMC chains and have settled on one of their hopefully more corrosion-resistant offerings in the hope that it'll allow me to continue running a waxed chain without it going ginger every time I have a wet journey.

No problem with knocking out a few links (other than them ultimately not getting used). I typically carry a spare quicklink or two and already have the luxury of chainlink pliers (at least at home!)

When I was " blinging " up my bike for the BWC I wanted to match the red/black colour scheme as much as possible. I fitted a KMC DMC 11 speed chain which I was advised wouldn't work. I adjusted the derailleur pusher screws and got it to shift successfully.

View attachment 700290

Nice work - interesting that the 11sp works on the sprockets as I'd imgine the rollers are narrower and the sprocket spacings wider. In any case, I'm happy to go with an 8sp as they're typically cheaper

Since I have 3 or more sprocket wheels for both my Bromptons I use 10 speed chains which work fine on the chainrings. I did invest in a Park tools power link plier which I really like and is kinda necessary with a 10 speed chain. I also wax my chains instead of oiling them and have an old crockpot with a mix of canning wax, oil and othetb things which I heat till the wax is liquid and soak the chains for a while. The wax doesn't pick up grit like oil does.

Cheers - as above, interesting that it's working with a narrower chain. I'm waxing too, which is why I need a more corrosion resistant chain!