Campag. Derailleur Help
Any advice on how to measure/set up chain length for my new Campag. derailleur?
I've just upgraded wifey's bike from a Xenon short cage (CT 50/34 cranks) to a Comp. Triple, and changed the cassette from 12-25 to 13-29.
Big->Big with the old chain length looks like it's about to pull the arm off, so the new chain will need to be longer - what are the fitting guidelines?
Campag's enclosed instructions are pants - no help at all.
I remember someone saying that Shimano and Campag. take different approaches to setting these up.
I was going to set it up so small->small is close to horizontal/at the end of the travel.
Given these daft single-use joining pins, I only get one shot at getting this right - unless I test out my chosen length with a screwdriver inserted/allen key.
Help!
I've just upgraded wifey's bike from a Xenon short cage (CT 50/34 cranks) to a Comp. Triple, and changed the cassette from 12-25 to 13-29.
Big->Big with the old chain length looks like it's about to pull the arm off, so the new chain will need to be longer - what are the fitting guidelines?
Campag's enclosed instructions are pants - no help at all.
I remember someone saying that Shimano and Campag. take different approaches to setting these up.
I was going to set it up so small->small is close to horizontal/at the end of the travel.
Given these daft single-use joining pins, I only get one shot at getting this right - unless I test out my chosen length with a screwdriver inserted/allen key.
Help!
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Comments
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You can either:
* Put it on the big chainring + big sprocket & add two links.
* Put it on the Big ring + small cog & set the chain length so the derailleur cage is vertical.
* Put it on the small ring + small cog & make sure the derailleur takes up all the slack.
Provided you're using fairly standard gearing (i.e. not exceeding 14-16T gap difference in the front rings, etc), you probably won't need to check all three options.0 -
The most important thing is that you can't break anything when riding. The only method which makes sure of this is the first of Synchronicity's suggestions - wrap chain round big ring and big sprocket (not going through the mech) and add 2 links. Given a triple and a wide range cassette, either of the other two methods might result in a chain which is too short, and hence you could break something if you change into big/big (it's not actually that important for the mech to take up the slack in small/small, as that's a gear you shouldn't be using anyway).0
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Just to let you know that under the instructions section of the Campag. website, there is a chain PDF.
This includes the "Campag. method" for calculating chain length -
It appears their derailleurs are designed such that when fitting, you put the chain small-small rings, then measure a vertical drop between top face of the chain on the chainring-return side, and the bottom face of the chain as it passes under the topmost derailleur's guidewheel.
The gap should be 10-15mm.
I recall that Shimano have the opposite approach, but can't for the life of me remember what it is!
Just out of interest, the article indicates that chain life is typically 2-5,000 miles (and the chain should never be washed with a garden hose).0
