Chain length

mcowan77

About to fit new 105 groupset

Best method for determining chain length?... Fitting 10sp KMC chain

Thanks

g00se

it's all here: http://www.parktool.com/blog/repair-hel ... gth-sizing

And if you want to use the rigorous equation, use this: http://www.machinehead-software.co.uk/b ... hcalc.html

drlodge

Chain should be as long as possible on small-small with the RD still taking up a bit of slack.

arlowood

Don't bother with all that chain threading on big/big malarky. Just use the equation link supplied by g00se or this link (which will give the same answer)

http://www.epicidiot.com/sports/chain_l ... ulator.htm

Have used the calculation method several times over recent months on bike builds - works every time and no need to faff around before hand.

Essex Rouleur

Put the front derailleur in the big ring, the rear derailleur in the small ring, run the chain over the big front cog back over the small rear cog, through the rear mech and pull the chain together at the bottom until the jockey wheels on the rear derailleur line up vertically under the center of the rear cassette. Where the chain overlaps and meets, thats where you join the two ends together, removing any links not needed.

Always make sure the outside links are on your right and the inside links are on the left when you insert the connection pin.

drlodge

Essex Rouleur wrote:

Put the front derailleur in the big ring, the rear derailleur in the small ring, run the chain over the big front cog back over the small rear cog, through the rear mech and pull the chain together at the bottom until the jockey wheels on the rear derailleur line up vertically under the center of the rear cassette. Where the chain overlaps and meets, thats where you join the two ends together, removing any links not needed.

Always make sure the outside links are on your right and the inside links are on the left when you insert the connection pin.

That is simply going to give you a chain length that "looks nice" but it won't guarantee its the right length.

The Mechanic

drlodge wrote:

Essex Rouleur wrote:

Put the front derailleur in the big ring, the rear derailleur in the small ring, run the chain over the big front cog back over the small rear cog, through the rear mech and pull the chain together at the bottom until the jockey wheels on the rear derailleur line up vertically under the center of the rear cassette. Where the chain overlaps and meets, thats where you join the two ends together, removing any links not needed.

Always make sure the outside links are on your right and the inside links are on the left when you insert the connection pin.

That is simply going to give you a chain length that "looks nice" but it won't guarantee its the right length.

Seems to work for all my bikes.

drlodge

The Mechanic wrote:

drlodge wrote:

Essex Rouleur wrote:

Put the front derailleur in the big ring, the rear derailleur in the small ring, run the chain over the big front cog back over the small rear cog, through the rear mech and pull the chain together at the bottom until the jockey wheels on the rear derailleur line up vertically under the center of the rear cassette. Where the chain overlaps and meets, thats where you join the two ends together, removing any links not needed.

Always make sure the outside links are on your right and the inside links are on the left when you insert the connection pin.

That is simply going to give you a chain length that "looks nice" but it won't guarantee its the right length.

Seems to work for all my bikes.

Depends how critical the chain length is. If you're on the limit like I am (34x50 chainring with 12-29 cassette) then there is only one length that will work - one link too long or short will not work.

curium

drlodge wrote:

The Mechanic wrote:

drlodge wrote:

Essex Rouleur wrote:

Put the front derailleur in the big ring, the rear derailleur in the small ring, run the chain over the big front cog back over the small rear cog, through the rear mech and pull the chain together at the bottom until the jockey wheels on the rear derailleur line up vertically under the center of the rear cassette. Where the chain overlaps and meets, thats where you join the two ends together, removing any links not needed.

Always make sure the outside links are on your right and the inside links are on the left when you insert the connection pin.

That is simply going to give you a chain length that "looks nice" but it won't guarantee its the right length.

Seems to work for all my bikes.

Depends how critical the chain length is. If you're on the limit like I am (34x50 chainring with 12-29 cassette) then there is only one length that will work - one link too long or short will not work.

C'mon! One extra link won't make much difference. If it does then you are already too far from the optimum.

Jon_1976

I always use the "big-big, bypass rear mech and add an inch/ 2 links" method. It's always been spot on and corresponds to the shimano method of jockey wheels perpendicular to ground when in big-small.

When I bought my Defy, I had to shorten the chain by 4 links to get it right :roll:

johnny25

I found this video helpful - http://roadcyclinguk.com/how-to/mainten ... -bike.html

paul_onabike

drlodge wrote:

Chain should be as long as possible on small-small with the RD still taking up a bit of slack.

This is the simplest way to get it right. You can work it out using whatever method/equation you want - but this is the critical point for chain length. Too long and it will foul the rear mech. Too short and it will strain the mech in the larger tooth size ratios. If the rear mech is overly strained in the large cassette, large ring setting, then you need a longer rear mech.