Campagnolo Thumb shifter sticking

Ben6899 wrote:

Check that the rubber hood isn't fouling the lever arm of the button.

Also, it's possible to inadvertently jam an Ergopower shifter, by accidentally resting your thumb on the thumb-shifter while using the brake lever paddle.

Interesting, I have the same problem occasionally, not often and not in specific gears.

That'll give me something to look at.

centimani wrote:

Ben6899 wrote:

Check that the rubber hood isn't fouling the lever arm of the button.

Also, it's possible to inadvertently jam an Ergopower shifter, by accidentally resting your thumb on the thumb-shifter while using the brake lever paddle.

Interesting, I have the same problem occasionally, not often and not in specific gears.

That'll give me something to look at.

Same here. It happens very occasionally in some ultrashift centaur levers. First few times I ended up down-shifting to get use of the thumb lever back. Next time, I realised I could put my thumb under the thumb lever and a put of upward pressure would fix it (even though I didn't feel any movement). Didn't know what caused it but I am guilty of riding with my thumbs on the levers.

As others have mentioned it can be the Campag hoods fouling the return action of the thumb lever. They shouldn't do but sometimes the way the bars are taped doesn't allow the various lugs on the hoods to locate into their spots in the lever body, so the hood doesn't sit quite right on the lever. The hoods can also be softened and stretch if a lot of lubricant is applied to the lever internal - it seeps out and can damage the elasticity of the hoods.

More common are third party hoods fouling the mechanism.

Other things to look for are lever 2 (the one behind the brake lever) getting trapped against the rubber button on the back of the brake lever - this sometimes happens if the return action on the brake isn't as strong as it could be (corroded cable - inner or outer, kinked inner cable, tired spring at the brake, corroded brake pivots being the main culprits) and sometimes lever 2 not sitting in it's correct place "behind" the brake lever (this is adjustable but not a job for the consumer).

Early generation UltraShifts (2009 and 2010) sometimes stick as there was a small dimensional tolerance issue inside the body which Campag fixed by some custom shimming inside the lever, but if the internals get dirty (and they do ...) then the shims can get sticky.

A really dirty lever will stick, too, as will levers that have been flooded (as a good many we see have been) with WD40 ...

I should mention that another cause can be consumers stripping and reassembling their own UltraShift levers - the spring that returns the thumb lever can be overstretched and thereby waekened (it isn't the easiest spring in the world to relocate if you don't have the tools / do it all the time) and we see a few back that are victims of this.

HTH
Graeme - Velotech Cycling Ltd (Campagnolo Main UK Service Centre).