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Had to fit a new 1x11 chain on my stumpy yesterday but i think i have cut it too short, in the highest cog the mech is swinging out about 45 degrees forward and has a little play upwards. I let all the pressure out the shock and when pushed right down the mech has little/no play, not that i would ever use full travel when in the big cog.
Think ill add a link in tonight, is their any potential future problems of having my chain this short?
Cheers!
I think the way to measure a new chain is wrap it round the biggest cog in the cassette and round the front chainring - then add 4 links to that length. If full suss I guess you need to do this when the suspension is at the point when the chainstays are at their longest (most chain growth).
If it’s too tight and you combine full travel with the biggest cog at the back then you could snap the chain / mangle the derailleur / snap the derailleur hanger I imagine.
The only time I can think the biggest cog / full travel could occur is in a slow but large drop off where you’ve needed to pedal to lift the front (going too slow to manual) and then had a large suspension compression on landing.
add TWO links a link is a inner and an outer
If it will go into big / big and still have play then its OK.
Agree with TJ and Joebristol.
If you sized the chain correctly (big-big not through derailleur plus two links and accounted for chain growth by finding the point where the axle is furthest from the crank to make this measurement) then you have the right length of chain.
If you used the previous chain as a guide then you may have the right length of chain if the previous chain was correct.
If you did anything else, it’s probably wrong and you should fix it before you tear the mech off and jam it in the back wheel.
Does the amount of links you need to add not depend on cage length?
Nope. Cage length depends on the amount of spare chain you may need to keep under control.
Nope. Cage length depends on the amount of spare chain you may need to keep under control.
Caveat to that, if you add too many "spare" links to the chain you need a longer mech to soak up the excess.
e.g. if the rear mech has a nominal capacity of 35t, and you fit a 11-44 cassette then you've used 33t of capacity, if you then add an inner and an outer then you've used 35t, you can't then add another inner and outer link which some people like to do as it means you have the ability to shorten the chain by a full link if it snaps on the trail and still have access to all the gears.
Thanks for the replies guys, ill get in about it tonight and add a couple links.
e.g. if the rear mech has a nominal capacity of 35t, and you fit a 11-44 cassette then you’ve used 33t of capacity, if you then add an inner and an outer then you’ve used 35t
Except that the 35T capacity is based on difference between cog sizes. I have to admit I'm not sure how this applies to FS bikes where chain growth is an issue.
Two links basically is enough that you can shift in and out of the biggest rings. It also guarantees that if you freewheel down a hill after a steep climb you won't bottom out and rip your chain and/or rear end to shreds.
There are other guidelines for specific drivetrains, but biggest (including suspension travel) plus two will always avoid breaking things.
If you can shift in and out of largest gear (including suspension travel) it's long enough IMO. On the tandem I have sometimes over-shortened the chain by a link, when I accidentally go into max crossover it takes a lot of brute force and an allen key wedged under the chain to derail it off the largest cog.
Except that the 35T capacity is based on difference between cog sizes. I have to admit I’m not sure how this applies to FS bikes where chain growth is an issue.
Yes, but it does that by swinging back and forward, if you add links to the chain then it won't ever go all the way forward, and it can't swing back past it's limit so adding links (half links really, a "link" is an inner and an outer). So in reality you can't (or shouldn't) set up an FS bike with a mech that's at it's capacity.
I hadn’t considered this as a possibility, I tend to only have one missing link per chain and replace at the earliest opportunity if bodging a failure has caused me to have multiples in the same chain...