Brompton owners

What tooth chainring are you using?

I'll be picking up my S2L as soon as the CycleScheme voucher comes through, and I have a spare set of carbon Chorus cranks...

I'm using the standard 130BCD Brompton ring, 54t I believe.

I was asking on here about Campag cranks but getting hold of 3/32 single speed rings without ramps and pins in 54t (or thereabouts) seemed difficult enough in 130 or 110 bcd, never mind 135.

Yeah, single ring on Campag is a pain but I already have all the necessary bits to do it - I'll just use the existing 53t.

Here it is with the new cranks :)

The names Recall, ..... TurtleRecall, licenced to commute :)

Bike just needs some Bond-esque extras now :)

I was thinking more along mini rockets for rush hour moments with tail gaiters and cabs/whitevanman/bmws/audis/chelseatractors. :)

I was asking on here about Campag cranks but getting hold of 3/32 single speed rings without ramps and pins in 54t (or thereabouts) seemed difficult enough in 130 or 110 bcd, never mind 135.

Pricey

I wonder if running 110BCD improved clearance? Can't really check as I'm on the train.

Yeah, I think it would, but then I think I'd struggle to find suitable chainrings.

St John Street Cycles do a 50T onna 110BCD - Ed had linked to it earlier - that's the biggest they do on 110.
I've just sent one back to exchange it for a 52T onna 130 BCD.
Evans bumpf online gave the BCD of the Alfine chainset as 110 - so that's what I bought, and a chain guard - turns out that the Alfine chainset is 130 BCD.
I think I may've used some bad language.

And is that ramped and pinned?

That actually good news, as you can get 130BCD track chainring in 54t.

If running the old 1/8 chain, 56t is within possibility if clearance allow it.

http://www.spacycles.co.uk/m2b0s172p1238/STRONGLIGHT-130-BCD-zicral-1-8%5C-inch-44-56t

No idea if ramped and pinned, but massive!

http://www.spacycles.co.uk/m2b0s113p968/SPECIALITES-T-A-130-BCD-outer-57-59t

Ideal if I ever decide to race the BWC. :)

Nope. Mine isn't, anyway. They go up to 63T, I think.

I suppose it's not ideal, but a ramped and pinned chain ring does work fine. I'm using one with the 110 bcd fsa cranks, since 2-3 years on the Brompton, and all is fine...

I guess you are lucky, it's not uncommon for such chainring to pop out even on a fixed wheel drivetrain.

What, the chain popping out?
Can't see why it would but if it happens to people, there's nothing for me to argue about...
When I installed that crankset on the Brompton I had not shortened my chain enough and even then it wasn't going anywhere.
I used such chainrings also on many fixie skidder atrocity builds in my life because I didn't want to pay the premium for track rings, again with no problem.
So many things are big "no no" around bikes that I've done without dying... The best one would be the top to bottom wrapping of drop handle bars!

I'd happily admit a track one would look better though...

The original chainset was 50t (unless you had a 54t originally) so no shorten chain needed.

https://www.aliexpress.com/item/50t-52t-Litepro-CNC-lightweight-chainring-130bcd/32697545238.html

Hmm, 58t could be interesting.

Bought the 58t. Judging by the online Brompton gear calculator, that should give me 60" and 80". Having had a quick look at the folded bike, I don't think it'll foul anything.

The original chainset was 50t (unless you had a 54t originally) so no shorten chain needed.

Was a new Sram chain, so had to adjust length

How many links will I need for a 58t ring on a s2l with standard sprockets at the back? Got a spare chain waiting to go on once I get the new ring.

104 maybe (base on 2spd with 54t is 102, 2spd with 50t is 100)

Might be worth doing it by trial and error if your chain got a quick link.

Yeah it's a kmc something or other with quicklink so I'll dick about, but 104 sounds like it'd make sense. Cheers Ed!