Campag Centaur Thumb Shift

Lord Jimmy 7th

Hi, my thumb shift on the RH shifter keeps on getting stuck in the depressed position,
should i try to disassemble and regrease/see if anything is causing tension in there or just close my eyes and shoot some wd40 in there?

James

Monty Dog

Firstly, check that the brake hood or bar tape isn't fouling the mechanism, also check that the cables aren't gummed up under the bottom bracket. Next I'd release the cable from the front mech and try and work it back and forth with the lever to check it's all smooth. Also check the condition of the cable inside the lever, in particular fraying of the cable around the head. Finally, after eliminating all those, start looking at the lever itself and spraying some WD40 or GT85 might loosen things up. Whilst the lever can be serviced, it's a job for a competent mechanic as it's quite fiddly.

Flexisurfer

I have exactly the same issue with my Centaur and as it doesn't happen all the time it makes diagnosis a real pain. I normally just up shift when I sticks, that seams to free it off and I mainly get it in the front mech leaver rather than the rear?? Personally I think there is an issue with the internal workings on the shifter as it goes solid. You could strip it down but that could screw it right up.

Lord Jimmy 7th

Yeah, I usually up shift as well, mine is just the rear mech shifter at the moment.

furrag

My right hand shifter has started doing the same around the 3rd/4th sprocket which is a pain in the arse when racing or hill climbing. Bad darts from Campy 2011. A real downer on 2010's groupset.

Edit: What I find is that when I shift down, sometimes the downshifter paddle gets stuck a little behind the brake lever and doesn't return to its neutral position. That's why when you shift down again, the paddle will return, allowing you to thumbshift. Doing a Google search, a user called Crepello has exactly the same problem and offers a solution:

Crepello wrote:

I once had a similar problem. It turned out that the paddle was out of alignment, which ment that it fouled the rubber bumper on the brake lever (it wasn't returning 'home'). In this position, it makes depressing the button very difficult. I have never figured out why the paddle was so, and ended up having to glue a metal bumper right at the top of the paddle hinge, to stop the thing from projecting forward so much.

furrag

The said part by the way is EC-R030 and available from Sigma, posted, for 50p.