help! sticky campy centaur thumb shifters

[danield]

I am building up a bike with a ~2012 Campagnolo Centaur 10 speed group. I've used the (powershift) levers on a previous build, but hasn't seen much action, less than 1500 miles I think. Front and rear derailleurs and cables/housing are brand new. Anyways, I'm dialing in the shifting and encountering "sticky" thumb shifters when (1) shifting to the two inner-most front derailleur positions and (2) shifting down from the largest cog to the second and third largest cogs with the rear derailleurs. The button presses down and "sticks" -- I have to knock it again or flick it up to get it to click back up the starting position.

Any idea what if this could be an issue with the lever, or some kind of cable snag problem? I've built up a few other bikes with Veloce and Athena powershift systems and haven't had this problem before.

[Ralph]

Are you using cables designed for Shimano shifters? They have larger ends and can hang up on Campy.

[danield]

Originally Posted by Ralph

Are you using cables designed for Shimano shifters? They have larger ends and can hang up on Campy.

Thanks for the reply -- but nope, using Campy cableset

[zmudshark]

Is it catching on the hoods?

[FlashUNC]

Originally Posted by zmudshark

Is it catching on the hoods?

That's the first culprit, is binding in the hoods.

[maunahaole]

The thumb buttons can get sticky with sweat, etc. it should have a tiny bit of free play to engage the ratchet wheel. Peel your hoods back and put a drop of lube on the pivot point. Work it a little gently so it feels like is moves freely and smooth. It should only move a couple mm tops.

[danield]

thanks for the tips -- i had peeled back the hoods off of the thumb buttons entirely and they were still sticking, so don't think it's a hood obstruction issue. i'll try a little lube. i do tend to sweat all over my bike

[binxnyrwarrsoul]

Pull the hoods off and make sure the "slit" doesn't have any extra rubber, especially at the ends. Have had that happen to me on many occasions, more so with the 11S shape.

[beercan]

oldpotatoe should solve your problem

[ultraman6970]

Check out the cable spoolers,, sometimes the hole in the cable spooler is not too deep and a couple of mm of the cable head get off the cable spooler and you start getting a weird friction like the one you have when to smaller cogs.

Look inside of the lever with a flashlight and see what the cable spooler is doing, probably the cable head is tiny off. If thats the case just dremel the head of the cable, way easier than trying to fix the cable spooler hole.

Good luck.

[pdmtong]

Originally Posted by binxnyrwarrsoul

Pull the hoods off and make sure the "slit" doesn't have any extra rubber, especially at the ends. Have had that happen to me on many occasions, more so with the 11S shape.

i know you looked at it but this is by far the most common culprit...you take a scissors and open the slit further

oops...ignore I re-read your post.

[oldpotatoe]

Originally Posted by beercan

oldpotatoe should solve your problem

Powershift, no 'slit', just a hole and I would say some lube in there to ensure the spring lifts the thumb button aggressively. The thumb button is integrated into the body..

[danield]

Thank you everyone for the thoughtful replies. I was finally able to determe that the front of the hood covers had slid forward and were impeding the paddles from shifting back fully into their starting position, which must have in turn kept the ratchet from clicking back into place, which then caused the thumb shifters to stick. no idea why this only happened on low gears (cable tension?). i should have realized this problem sooner -- but again thanks for all the tips which i'll no doubt use for future troubleshooting.