For a 1×9 on a hardtail, I can’t remember. Is it chain on biggest ring at the back without going through mech, pull tightish and then add 2 links?

thats wat i did dude… works fine.

that’s the rule for all chain fitting – big-big+2

don’t see why it would be different for 1×9

Dave

Ace, cheers! Wasn’t sure if it’d be different for 1×9 but just thought I’d make clear what I’m doing 🙂

the other, and I think easier rule as it works on all setups with a rear mech, regardless of HT or FS is :

big ring at front, small sprocket at back, chain through mech as normal, set length so that jockey wheels are in vertical alignment. If you can’t get it exactly vertical, go half a link too short for a HT or half a link too long for a FS.

I’ve always done biggest ring and smallest ring and mech should be vertical – only works on hardtail though

If you can’t get it exactly vertical, go half a link too short for a HT or half a link too long for a FS.

Depends on the travel of the FS. That would’ve snapped the chain on my old M1

On 3 x 9 you never actually run the chain big chainring to big sprocket, so setting up a 1 x 9 on a big to big plus 2 (2 half links for clarity) might leave you with a chain that is too short. You need to run the chain through rear mech round biggest sprocket & chainwheel – then shorten the chain to the minimum (when there is visible S in chain where it passes through the rear mech) – see the advice on the Parktools website if not sure about this. My 1 x 9 works out about big to big plus just over 3 half links.