How do I work out the correct chain length

[Rooster1]

Hi
I've installed a full new chain (116 links) and it is obviously much longer than I need as the chain more than touches the derailleur when on mid rear cog and mid triple.

I've got a triple up front and an 9 speed 11-32 on the back.

I don't have the old chain as this is a new build for me.

What's the best way to figure out how many to take out. Was thinking to set everything to the mid cogs and then pinch the chain and see how many links are over until it is tight ?

 

[numbnuts]

Big ring front, big ring back

 

[raleighnut]

Run the chain over the biggest sprockets (but not through the rear mech) then add a pair of links, that'll give you the right length.

 

[Asa Post]

Take your pick:

http://www.parktool.com/blog/repair-help/chain-length-sizing

http://www.machinehead-software.co.uk/bike/chain_length/chainlengthcalc.html

 

[Rooster1]

Cheers. I will add a quicklink too.

 

[JtB]

Run the chain over the biggest sprockets (but not through the rear mech) then add a pair of links, that'll give you the right length.

That's also the Sheldon Brown method.

 

[raleighnut]

That's also the Sheldon Brown method.

I'm in good company then, I was doing it that way long before I ever looked at t'internet, same as lubing a chain and wiping the excess oil and muck off with an old rag.

 

[Smokin Joe]

Take your pick:

http://www.parktool.com/blog/repair-help/chain-length-sizing

http://www.machinehead-software.co.uk/bike/chain_length/chainlengthcalc.html

+1 for machinehead.

That site is well enough known, I've posted countless links (See what I did there?) to it over the years. Why anyone would F about with any other method beats me, it's so simple.

 

[Joffey]

+1 for machinehead.

That site is well enough known, I've posted countless links (See what I did there?) to it over the years. Why anyone would F about with any other method beats me, it's so simple.

Strangely I used the little Machinehead calc and the chain was far too long. Opted for the big ring big cog method and took an extra 3 links out to make it fit. It's perfect now. User error probably!!!!

 

[Dogtrousers]

I replaced my chain at the weekend. I was going to just use the same length as the old one, which was fitted by my LBS, but found that the standard 114(?) link chain that I'd bought was too short. So I re-did the big-big @Ralieghnut / Sheldon method and found that my chain was about two pairs of links too long. (ie 2" - I get confused by what is "one link" - is it a pair)

Hadn't caused me any harm - the long cage derailler happily ate up the extra - apart from lugging all that extra weight around. But for that extra weight I coulda been a contender.