Campagnolo brake caliper problem

rowlers

Single pivot rear Skeleton (Centaur 2010).
Fitted to new frame last week, and has been sticking ever since. (may well have been sticking on previous frame - can't be sure)
I've searched and read that it could just be gunked up, so cleaned and lubed and it is nice and smooth off the bike.
As soon as its fitted though it will not spring back out to clear the rim, I can move it back with my hands.
Is it just worn? Do I need a new one?
Any clues as to how I can get it working for tomorrow sportive?

thanks

Edit, I've tested the cable and it is NOT that, nice and smooth when operated by hand.

Monty Dog

If it springs back when disconnected, the its down to sticky cables

rowlers

Monty Dog wrote:

If it springs back when disconnected, the its down to sticky cables

Cables are brand new though and they are smooth as silk.
It seems, that as soon as I tighten the caliper to the frame the pivot starts to bind, which makes me think something has worn. I cannot find any decent Campagnolo tech docs showing the trip down of a caliper either... :?

Monty Dog

Check that you haven't over-tightened the bar tape, it can restrict the cables. If you download the Campagnolo spares manual, you'll get an exploded view of the caliper assembly. If you strip the caliper, you'll need some tiny Allen keys and some Loctite for reassembly

g00se

I found that if the last bit of outer from the back of the top tube to the calliper is a certain length, then the turn in the outer will hold the calliper-end of the outer onto the brake and stop it retracting properly. Try cutting a centimetre off of it - or replace it with a piece about a centimetre longer. If it's a bit shorter, then it won't some down straight onto the calliper arm. if it's a bit longer, then there's more movement and flex in it to be pushed back.

rowlers

g00se wrote:

I found that if the last bit of outer from the back of the top tube to the calliper is a certain length, then the turn in the outer will hold the calliper-end of the outer onto the brake and stop it retracting properly. Try cutting a centimetre off of it - or replace it with a piece about a centimetre longer. If it's a bit shorter, then it won't some down straight onto the calliper arm. if it's a bit longer, then there's more movement and flex in it to be pushed back.

Now that is something I can try. Cheers...

Monty Dog

To eliminate it being a caliper issue, mount it to the frame, don't connect the cable and see if it's still sluggish to return? My money's on your cable run being too tight or somehow creating cable drag.

rowlers

Monty Dog wrote:

To eliminate it being a caliper issue, mount it to the frame, don't connect the cable and see if it's still sluggish to return? My money's on your cable run being too tight or somehow creating cable drag.

Yep I'll try that too,