front mech alignment

bice

I have built up a lovely Italian steel frame, fitted out with assorted Campagnolo bits.

I just want to know whether I have got the front mech as good as I am going to get it.

I have a Campag Record 53/39 chainrings; veloce 10-speed 13-26 casette; Chorus 10 speed rear mech and Centaur front mech.

With the big chainring I can go up the casette to the fifth-sixth largest cog before the chain brushes against the inside of the front mech.

On the small chainring I can go down the cassette to the seventh (ie third smellest) cog before the chain rubs against the outside of the front mech.

Is this as good as it should be? I have set it up so there is no rubbing on smallest chainring and largest rear cassette, as that is when stresses are going to be greatest. Obviously I can get less rubbing with the other cogs by moving the front mech in a bit, but that seems a wrong move.

I am a bit disappointed as my Shimano triple on a Trek 1.7 only has chain rub as the extremes of the gears. however, with a double, with this size chainring, this might be 'normal'. Any views?

Meds1962

If you set up the limits and cable tension on the mech correctly there should be no reason for you to have any chainrub (or at least very minimal).

In the small chainring / largest sprocket combination you should have the mech within a couple of mm of the chain and the same for the large chainring / smallest sprocket combination. Basically the closer the mech is to the chainring at either extreme (without the chain touching obviously), the greater range the chain will have to shift accross the cassette without touching the opposite plate.