Hi all,

I will be trying 1×9 and was just wondering how best to judge the correct chain length.

Chain on big cassette ring and front ring (not through rear mech) and plus 2 links as per normal?

I imagine it doesn’t matter too much so long as the rear mech isn’t stretched too much when in the big cog and doesn’t collapse on itself in the small cog.

Any thoughts would be much appreciated!

Thanks in advance, DanW

Set up with chain through everything and work out what too much slack is.

I went about 3 links less than snapping it.

Much easier to do as there is only the 1 ring

A bit more of a “do it by eye” approach then for 1×9?

Is there an optimal range for a rear mech to work in? Is there any advantage tp the chain being towards the slacker end or tighter end of the spectrum?

You set it up as you would a 2x or 3x.

as short as possible = big sprocket + 2

as long as possible = wee sprocket + as much as the mech will take

(different AWESOME opinions also exist)

Is there an ideal amount in between the two extremes?

I call Troll. 🙄

You need enough chain to use all the gears without snapping the mech. You can always take more out after.

Just do it like you normally would, big sprocket plus 2 links.

Chain on big cassette ring and front ring (not through rear mech) and plus 2 links as per normal?

Big/big is a usuable combo on a 1×9 and as said above, route the chain around the cogs and through the mech. A short cage mech will not have the capacity of a long or medium cage mech and you might be surprised how much it has to extend in the big/big combo.

Also remove the shock if your bike has one and make sure the chain length is OK big/big as the swingarm moves.

Pinkbike article

Good point on checking the suspension effect on chain length!

It can make quite a difference on a FS