Campag rear mech set up

pieinthesky

My new ish bike has a Campag Chorus triple rear mech. It shifts OK but not brilliant, sometimes it just doesnt want to change sprockets. I have checked all the normal things, cables etc and all is OK.

Looking closely at the mech, the upper jockey wheel is always 20mm or so from the teeth on the cassette. On all previous bikes (Shimano mostly) the gap has been much smaller.

I have tried adjusting the H screw as instructed in the Campag instructions and it is adjusted to its limit. If I screw it back it makes the gap bigger.

Is this gap normal on Campag Mechs and will reducing it improve shifting, and if so how can I do it?

If anyone can answer this one I will be impressed.

Thanks Pie

pieinthesky

And I forgot to say:

The only way I can see of adjusting the jockey wheel towards the cassette it to file down the stop on the gear hanger.

I dont want to do this without making some enquiries first, hence the question!

JWSurrey

Something does not sound right.
My wife has a comp. triple, and it actually sits ridiculously close to the big ring.
Changes are pretty good, however the spring tension on the hanger is not as strong as I would like.
The bike it's fitted to has a very stiff ratchet/pawls, however it is actually possible with the chainset crossed over little to little, to end up with so much chain slack that it will touch the bottom of the front derailleur and the chainstay when back-pedalling!
(Yeah, I know you're not supposed to cross it over).

That screw thing seems to not make as much difference as I expected.
Have you measured the hanger plate - The campag. site has details on suggested size of hanager plate.

Did you follow the fitting instructions? I think it states that you should run the chain small ring to small ring, and there should be 10-15mm of stand off between the topmost jockey wheel and the chain on the "incoming" side.
I found it better using the more traditional method of making the chain 2 links longer than the shortest it could be.

Steve928

JWSurrey wrote:

I think it states that you should run the chain small ring to small ring, and there should be 10-15mm of stand off between the topmost jockey wheel and the chain on the "incoming" side.
I found it better using the more traditional method of making the chain 2 links longer than the shortest it could be.

I agree - I've never understood the big+big+2 links method of chain fitting. I always fit my chains as long as they can be i.e. small+small and then take out the fewest links possible to have the returning chain clear the jockeys (allowing for chain stretch in use..).

This keeps the mech running as close to the sprockets as possible for snappy changes, and also maximises the capacity of the mech (for example you can run 53/39 and 13-29 on a short cage mech without problem even in big+big).

pieinthesky

Stevecp My chain clears by 35 to 40mm and is therefore a bit short. However simulating a longer chain by dropping the chain off some of the chainring teeth, reduced the clearence but did not move the upper jockey wheel any nearer the cassette. Will a longer chain therefore make any difference? I am not going to try and lengthen a 10 speed chain but will try it next time I replace it

JWSurrey I have checked the hanger against the campac spec and it is within limits except possible angle B which I measure at about 40 degrees.

Thanks for your help

Pie

pete.whelan

On Campag the 'B' screw adjusts the distance of the jockey wheel from the cassette cogs. This is hidden See http://www.cyclingnews.com/tech/fix/?id=howfix_deroh

JWSurrey

Thanks for the link Pete - I'd been playing with that screw, but hadn't realised there may be two spring tension settings points.
Might strip it down next weekend and see if I can up the tension.