Howdo!!
Can anybody help me please.Time has come to change my chain the problem is i don't have any LBS in my area.So i decided to do it myself,so here's the spec lowdown :1 pc971 chain(9 speed),1 pg990 11-34 tooth cassette,1 FSA team issue crank,1 sram xo rear mech(short cage version)

The problem is that i followed SRAM's instructions about placing the chain without routing it through the front or rear mechs on both the largest front ring and the largest rear,and then pulled both ends of the chain together,then as instructed gave it 3pins of slack.My problem now is the when i'm in the granny ring and the smallest cog on rear cassette the chain rubs along the rear mechs cage thus indicating that the chain is still to long.

Then to make matters more confusing a mate of mine told me i should of placed the chain on the granny ring then threaded it through the rear mech and then around the smallest rear cassette ring and then pulled it tight to the point that the tension of the chain pulled the mech down thus giving the chain free passage without rubbing on mech cage…phew!!

please can anybody cast any light on this subject,and thank you for your time.

your chainline in little little is shit.

Granny ring and big 3 at the back
middle and middle 3 at the back
large and smallest 3 at the back

if these work its fine imo

why are you running a short cage mech with a 34t cassette? is that right? Is the crank a triple, if so definitely not right

Big front + Biggest Rear, no mechs included and add 2 links.

Never run the bike in the granny and smallest rear cog, it's a recipie for disaster.

All you need is in this web site http://bicycletutor.com/ 8)

I route the chain through granny ring, small cog and through mech, then pull bar tight and break the chain. They suggest their method as it is a bit easier than trying to hold everything together but its a general method that will probably leave your chain too long still.

I like my chain as short as possible, but going too short will result in tears if you do accidentally shift into a poor combination…either a snapped chain, a bent large chainring or a snapped mech hanger will be the result. I lent one of my bikes to a friend the other day, he promptly shifted straight into big big and I was so glad I'd added a few links after swapping the chain from another bike a few weeks back knowing it was a little short!

You also need to add a little extra to the chain if you have rear suspension that makes the chain tighter on compression.

What ROFL said, a short cage rear mech is designed for a single front chainring, if you try to run a short rear mech with a double or even a tripple front you won't get the cage span to keep tension over the whole gear range 🙁

What steve_b77 said. SRAM, Park Tools etc all say big/big without mech plus two links (one inch), and err on more rather than less if it doesn't quite go. If you are running a triple ring, a long cage is mandatory

What they all said about big/big without going through the rear mech.
For ultimate piece of mind if you have full suspension, do it with the rear suspension fully compressed, i.e with the spring removed or air out of the shock to allow for any chain growth.

What twohats said, except on some bikes the chain length will grow as the suspension extends, so do it with the shock pressurised 🙂

You do know what chain growth is don't you?
Compressing the suspension on the majority of most bikes usually causes the wheel to get farther from the bottom bracket (i.e all single pivot bikes, most linkage bikes, and the more travel you have, the farther it moves away), thus the chain is required to "get longer" but physically it can't, this is known as "chain growth"!!!
There are very few designs out there where the wheel actually gets closer to the bottom bracket creating a "chain shortening" effect!
My above post still stands 😀