Ay folks have a problem running a Dura ace FD 7403 front derailer with campy cranks the ones with the different coloured lines around them.¨Record... Anywho when I shift to the big ring it touches the crank arm. Its a brazed on derailer and the frame has none so I had to get the clamp for it . I dont want to go bending and ruin it. Or could it just not be compatable. THANKS

They say there's no stupid questions so here goes...have you adjusted the outer limit screw on the derailleur?

Yes. No matter howI fine tune it it will touch the arm. Im thinking rails are to far apart but both sides are straight.I have it runing straight with the chain rings ... I dont know.

what kind/model Campi crankset do you have? "different colored lines around them" just means that some company paid to have it pantographed. is a 7403 a 8,9,10 or more spd derailleur? are you using a friction DT shifter? it may just be a fact of life that you have to 'trim' once you shift to the big ring.

the Shimano FD-7403 came in two flavors: FD-7403 B and FD-7403 F. One had the clamp (F), the other did not (B). I think that your problem might be that either a. the clamp (did you get an aftermarket clamp to put your braze on FD?) is too thin or b. the derailleur is mounted too high on the ST. I would suggest to trade your braze on derailleur for the one with the clamp, here on the ISO/for trade forum (I am sure that folks here have some of them sitting around) and take it from there...

Can you rotate the clamp and FD slightly so that if clears the crank? I was having a similar problem with a suntour FD and lining the FD up correctly fixed it.

Is the derailleur cage exactly parallel with the chain rings?

I am assuming if you adjust the derailleur so it does not hit the arm, it does not shift to the big rings.. I would say that even though the rings clear the stays, the crank is too close. If you have a post-CPSC crank on a pre-CPSC spindle, it will sit too close. Usually it will mean the rings hit the chainstays, but not always.

I changed the BB to a sealed one yu think it may be the wrong one the frame I think is a late 70s or 80s could I have put it in backwords will it go in backwords.

It may be the BB is too short, then. Just how much clearance is there between the chainrings and the chainstay? And you never did say what model Campag crank you are using. Check the back for a date code. Should be a number in a diamond or a circle. Also, you say the BB can go in backwards. That implies to me you can adjust it.

Ive got it working My seat tube is 28,6 so using a larger adapter clamp and a spacer moved the derailer back. thanks everyone