When all else fails RTFM (and a Campy secret handshake)
 

I took my main bike for a longer ride yesterday, a flat 35 miles along Rockaway Beach in NYC. Through the whole ride though I kept thinking the shifting still wasn't right on my Chorus 10 setup, and I had just taken off the cassette, cleaned it, and gone through the Park Tool method to adjust the derailleur. Last time I did it it worked beautifully. This time though I spent every ride so far trying to tweak it but couldn't get it right. Then it dawned on my, what if the spacers that I thought were all the same, weren't? So I pull up the Campy manual online, take off the cassette, and sure enough I swapped two identical looking spacers that were different thicknesses. Luckily the spacers are stamped with their thickness. I put it back together, correctly this time, and now it shifts like brand new after a few quarter turns of the adjuster.

Which spacers go where?

I ride Campy 10 too and sometimes it's perfect and others, not. I occasionally remove the cassette, so I could have scrambled the spacers.

I have a 12-25 on one wheelset and 12-30 on the other, the 12-25 does shift better. I figured this was due to range. Who knows?

when I open a new cassette I use a small file to notch the spacers, one notch for the first spacer, two for the next one etc etc. Reassembling the cassette is foolproof after that

Look in here: Campy Cassettes There is a diagram with each of the standard cassettes that they've sold in 10 & 11 speed. There is mention of joined large sprockets but mine were loose and the diagram shows it that way.

The spacers are marked with their thickness, but you need the manual linked above to know where to put them. In my case I had the 1.6 swapped with the first 2.4. And those were the gears that were noisy that also didn't shift well, or when I made it shift well there the others would not. Now it is click, click, click. And because the shifter was readjusted back to where it should be, the 2nd small cog shift works. It wasn't going up before but would skip it when I went to 3rd small cog.

And really, it was more annoying than anything else because I just couldn't get it 100% right.

I used to buy Campy Veloce 10-speed cassettes that had all loose cogs so you needed a spacer between each of them. I had to follow the instruction sheet's directions very carefully every time I assembled them to be sure I had the spacers in the correct positions. They were nothing as simple as Shimano cassettes where all of the spacers are identical.

One trick I use is to put a plastic electrical tie though the center of each cog or spacer as I pull it off, which keeps everything in the correct order and facing the right way. You can close the tie backwards so you don't have to cut it to reopen it.

I see what you are saying, but it's also not particularly complicated to simply follow a diagram indicating which spacers go where...

The cassettes now come on a plastic spline that is used for mounting and dismounting. Not sure when they started using them, but it's a pretty handy way of keeping things organized (until they accidentally slide off the spline).

The plastic splines were always on the cassettes that I bought. The question is which bin o' crap did they end up in? And the real issue is that I took it apart to thoroughly clean it, in which case it all got mixed up in the cleaning fluid as much as I tried to keep it straight.

As the title of the thread says:

RTFM!

Different thickness spacers on the same cassette is one of the dumber things Campy has done recently (but not a huge deal.) Fortunately, you can avoid this confusion and a dozen other issues by using Campy 10-speed brifters with a Shimano 8-speed system, because the cable pull is exactly the same. Though I've moved onto downtube shifters now and have little use for brifters.

If I'm going to spend the money for a Campy 10sp systen the last thing I would do is dumb it down to Shimano 8sp. 8sp was never a popular system. We went from 7 to 9 to 10 to 11. 8 just never caught on.

I run Campy Ergo 9 speed levers but on Shimano 9 speed cassettes so my understanding might be tilted... (by the ShiftMates I use)

Isn't Campy still using cog C-C spacing that's the same across the cog set? If so then any between cog spacers are sized to take into account the cog's thickness to result in the teeth being "on center". If so then one needs to pay attention to the cog's "root" thickness WRT the spacer. Andy

It's pretty much to account for the depth of the some of the joined cogs.

I had it all apart today and it was no big deal. Pretty obvious really where they go. My crunchy shifting is because I'm missing a spring on the barrel adjuster, so it doesn't stay in place.

It's not a problem to eyeball the right spacer, as long as you're aware that there are different sized spacers.

I learned something new today though, so that's pretty cool.