Probably a stupid chain length question

[mwktar]

Hi guys, need a new chain for my Spesh secteur sport 2011, but don't have the old chain to use as a reference for length, any Idea if i can get hold of the link length it would have come with?

Have had a search online and could only find that it had a KMC X9 chain, but not the no of links

 

[bikeman66]

There is a website (which I seem to remember is called something like "machine heads")which has a chain link calculator. You basically input a couple of bits of information about your bike and it will tell you how many links you require. I'm just going to see if I can find a link to it. Hopefully I'll be back in a bit, but I'd bet someone else will be along in a minute to confirm the website I'm thinking of.

 

[mwktar]

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

Awesome!

 

[Dogtrousers]

Wrap the chain round the big chainwheel and biggest sprocket. Pull tight, then add an inch (two rivets worth) to account for derailleur wrap.

Alternatinely, write down the number of teeth on your big chainwheel and biggest sprocket, measure your chain stays then search the web for "chain length calculator".

Or do both.

 

[bikeman66]

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

Awesome!

Haha! That's the one!

 

[mwktar]

Stupid question follow up - when i put in the info it returns with a 53 link recommended result - does that make sense? As the chain comes in 114 and 116

 

[bikeman66]

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

Awesome!

I'm sure that the chain stay length is centre of bottom bracket spindle to centre of quick release. It seems to give links required based on outer links only too.

 

[bikeman66]

Stupid question follow up - when i put in the info it returns with a 53 link recommended result - does that make sense? As the chain comes in 114 and 116

So I think you'll actually require 106 links. Chains are supplied with a standard number of links and you then shorten it to suit using a chain tool. Must admit, I usually use a non-Shimano chain, purely because those special joining pins are an extra pain in the arse you can do without. I usually favour KMC. Good value, no special pins and pretty much just as well performing as Shimano.

 

[Cubist]

Stupid question follow up - when i put in the info it returns with a 53 link recommended result - does that make sense? As the chain comes in 114 and 116

53 links is full links, ie one link with a plate and one link in between, so your answer is 106.

Wrapping the chain around the largest chainring and largest cog then adding two full links, plate and no plate links is a good start. Start like this and try the gears in the work stand in both extremes, ie big- big, where the chain running through the mech cage should still have a vague s shape, and in small-small where the mech cage should still just take up a bit of slack in the chain. If the mech folds all the way back on itself in small small and the chain goes slack, remove one link and try again.

Edit: and as @bikeman66 says, using power links instead of joining pins makes the whole process much simpler.

 

[mwktar]

ahhhhh - cheers for this guys - only just getting into the whole serving of my own bike (practising on my old one ) - just assumed you bought the size you needed!

God help my bike hey!!!

 

[MichaelW2]

Parktools repair website have three different methods of determining chainlength.
It is really easy to cut a chain 1 link short. so think twice and cut once.
Factor in the extra quick-connecting link.