I'm having a problem that I'd like to diagnose before I bring it into the shop. I don't trust the guys by me and if I can fix it, all the better. Here's the deal:

Bike is shifting to another gear with a big "Chunk" mostly when I stand or put a heavy load. I can't reproduce it on the bike stand. It happens in big and little ring, various cogs in the back, but smallest cog in back in particular. I noticed that when I PULL on the rear derailleur cable, the right shifter clicks into the next gear. This doesn't happen on my other bike, which leads me to believe that it is a problem with the shifter, but I'm not sure. Otherwise, the shifter clicks just fine up and down. I'm guessing this shifter has about 7000 - 10000 miles on it since it was overhauled (I got this bike used, I put around 6000 of those miles on it).

I'm running Campy Record/Ultegra 10sp mix, new(ish) chain (about 150 miles). I just replaced the cables and housings (maybe I did something wrong??). Cassette & wheels arent the issue because I tried two separate wheels w/ two different cassettes and problem persists.

Thanks - I'm trying my best to learn!

Aside from the obvious like miss adjustment, has your derailleur hit something and bent the hanger? To check this, shift to the middle cog then look at it from behind. The chain should follow a straight line from the cog through the jockey pulleys of the derailleur. If not you might have to tweak the hanger. Also check that the hanger is not loose. I had a loose derailleur hanger that drove me nuts trying to adjust the shifting until I found the real issue. Tightened the 2 little hex head bolts holding it and it worked like a charm.

1) That's not out of line with the mileage I used to get out of G-springs (I shift like I have ADHD)

2) The right G-spring carrier fatigues and breaks too with similar effects. Mine always seemed to last through about two G-spring sets. I'd suspect that if it wasn't replaced when rebuilding the shifter.

To speculate on how this leads to load dependent shifting: maybe your rear triangle moves a bit under heavy load and the derailleur spring is stiffer than the weakened shifter detent mechanism so the shifter is moving a cog smaller instead of the derailleur briefly pushing the chain towards a larger cog.

This may be worn index springs, but that usually shows up first in low gear where cable tension is highest and works down from there as the springs continue to weaken. I usually have no problem causing an upshift in the lever by pulling the wire away from the frame, but as the springs weaken this gets easier.

However, if you don't notice the lever clicking by itself, and if the slippage is happening in any gear, there's a good chance that the problem is simply trim that's adjusted slightly outboard of center. Folks do this when housings get a bit worn or dirty because the RD spring is sluggish making upshifts. That improves the shifting, but at the cost of what you're experiencing.

One test for sticky housings is to upshift, then pluck the wire at the downtube. If the sudden snapping action moves the RD out a bit more you have sticky cables. The solution is to fieldstrip, clean and lube cables or to simply replace them if they're old. Be sure to cut the rear loop long enough that it comes into the RD adjuster straight on.

BTW- while you're there, take a quick look at how the rear loop lines up with the adjuster. If it leaves at an angle, that could be the problem right there.
Test by using a rubber band to flatten the rear loop so it lines up better and see if things improve. If so, you can either replace the rear loop, or leave the rubber band in place, though half your buddies will ask why it's there.

Ok this seems to be the issue. From other people I talked to it sounds like the spring is wearing out (or some other part in there). Taking it into the shop.

Also, when the shift occurs I've "felt" it in my right hand, kind of like if I gripped hoods too hard it would cause a shift (fingers OFF the lever). But it happened in the drops too, so I originally ruled that out. So I'm fairly confident that it's a shifter issue now.

Thanks for the help!

TO me sound like a problem with the g-springs and i would change the carrrier too.

One detail, what campagnolo are we talking about here? Campagnolo 10 has 2 mechanisms and if you have scape the gsprings and carrier solution wont work because escape doesnt have those parts at all.

Are you sure the cables are ok? some clueless campagnolo users just think the cables do not need adjustments and after a couple of years they complains saying that campy sucks when is clearly a user problem.

Good luck.

Your problem is probably a result of a Campagnolo/Shimano mismatch. https://www.ctc.org.uk/cyclists-libra...gears/shimergo Assuming you are not using a shiftmate, as the drive train wears the mis-match problems become more evident. In your case the chain has been the verge of shifting (and does so by simply pulling on the rear derailleur cable). you say you have a new chain (150mi); I would venture to guess the ghost shifting started with the chain replacement..either way you might want to look into a shiftmate. Also you may have a small kink in the new housing which can cause this problem.

I find with all the engineering to make early shifting, the shifting ramps on the sides of cogs
and the shortened teeth.. picks up the chain even when you Don't want it to..

the index click may be off center of the cog.. and getting lifted ..

a typical 1st check, Dropout eyelet allignment tool...

I did not read the part of the mixing campagnolo shimano... is this guys using a jtek unit or playing with the hook in the RD? If its straight clearly it wont work.

In theory it will work.

The writer of the CTC Shimergo web site explains.

In theory, we ought to be able to predict the overall width of a cassette from sprocket pitch × (n – 1) + the thickness of a sprocket. For some cassettes that works, but others are wider than we'd expect, with the top two or three sprockets spaced a bit further apart. That's not a problem because the first click of the shifter always pulls some extra cable so as to take up any slack, with indexing of the top sprocket provided instead by the mech's high-gear stop screw. The low-gear stop does a similar job at the other end of the cassette, so that only the intermediate sprockets are actually indexed by the shifter. This is part of the reason some "incompatible" combinations actually work okay – at least when new. With only seven out of nine sprockets dependent upon the subtle relationship between cable pull and shift ratio and with indexing set on the middle one, the maximum shifting error is only three times the error per click. If, for example, the mech shifts 4.55mm instead of 4.35mm, the most it'll be out is only 0.6mm, and only in next-to-top or next-to-bottom. The rest of the reason is that the guide pulley can float about half a mm side to side, allowing at least that much misalignment between mech and sprocket without any nasty noises. Add a bit of friction though, plus some wear and tear, so the mech position varies by a millimetre or two depending on whether you're downshifting or upshifting and that 0.6mm may be all the difference between shifting or just sitting there and rattling!
https://www.ctc.org.uk/cyclists-libra...gears/shimergo While I was upgrading one bike from Shimano 9 speed to Campy 10 speed, I tried the Campy shifters with a Shimano 9sp derailleur and Shimano 10sp cassette (for no other reason than to see if it would work). It actually worked, sort of. So if one is not too picky with the quality of the shifts, it will work, but as the CTC writer said, at least when new

No no - definitely NOT shimano/campy mix. I miswrote the post originally - so sorry, I meant Record/CHORUS parts. Record 10 shifters, Chorus derailleur. No clue as to why I wrote Utegra - I only have one bike that uses Shimano and it's my wife's. And it's 105. I think I've been working too hard lately!

Oh and it's new cables & housing too...

Okay. First when did this start happening? Did it correspond to the new chain or housings? Or were these down trying to fix the problem?

It sounds to me like your frame is flexing (under load). Same thing was happening on my wifes mountain bike. Go to an auto parts store and get Dielectric grease (couple of dollars). You may want to pull the cables out of the guide that is running under your bottom bracket, clean it and then put the grease in its tracks (the grease is made so as not to dissolve plastic) and re install your cables.

Good solution, but the cause is wrong. Cable friction, either in the housings, or at the BB creates trim problems and can lead to ghost shifting to the spring side (smaller sprockets for Campy and most RDs). but if frame flex were (is) a factor, greasing the BB guide wouldn't address it.