Bianchi 928 chain rub on seatstay

magliaceleste

I've got a 2006 Bianchi 928 frameset built up with Campagnolo Record Compact Chainset, Campag Zonda wheels and a Centaur 11-25 cassette (all 2007) and am using a KMC X10-SL chain.

The problem I am having is that the chain is rubbing when on the 11T rear and 50T front on the driveside seatstay.

Any ideas what I can do? Seems a strange design flaw

Thanks

Aidocp

It must be the set up I've got an almost identical bike but Veloce and I don't think it rubs in that gear but then again I'm hardly ever in it :oops:

magliaceleste

Thanks.

There is nothing to adjust with Ultratorque though, The Chainline at the front is the chainline. How close is the chain to the stay on your bike when in the smallest sprocket? Are you running Compact with 11-25?

Aidocp

Yeah is the same set up a compact with a 11-25

magliaceleste

OK well something is wrong then, it must be cassette, frame or wheels.

What I don't like is the fact that the rear mech limiter has to be right out to get into the smallest sprocket. I think it's a cassette or wheel problem.

What wheels have you got?

Aidocp

Campagnolo Khamsim

Monty Dog

It's to do with running an 11 tooth sprocket - it's down to the shape of the rear dropout/chainstay - you're going to have to change to a 12 tooth. It's not unknown for people to wreck a frame by wearing through the chainstay!

magliaceleste

Bug*er. It's quite handy having an 11T.

I'm sure it didn't rub when I had a Shimano 12T on the rear but it was damn close.

Something to look out for on my next frame.

Thanks

Jajacp

I thought it was the seat stay you said it was rubbing on - in which case a larger sprocket would make things worse. I used to have an omega which wouldn't acept anything larger than an 11 with out rubbing the seat stay. If it is the chain stay the the converse is true.

LangerDan

It might be worth checking that the cassette is seated properly and that the lockring is sufficiently torqued up. I had a similar problem earlier this year and removing and reinstalling the cassette and lockring sorted it.

magliaceleste

Thanks guys. It is indeed the seatstay, I don´t remember it rubbing with a 12 but it was also with a different set of wheels. I´ll remount the cassette and see what happens. I also might try a different chain.