onespeedbiker

Okay, I was running a hubub system, 10 speed Campy shifters with a Shimano 9 speed derailleur and cassette; worked great. Having way to much time on my hands, I then added a Campy 10 speed derailleur with a Miche Shimano spline and spacing, 10 speed cassette and switched out 7 of the 10 Shimano spacers for Campagnolo spacers. The system worked pretty well, except for a rough shift in the area of the 6 and 7 cog (smallest to largest). which could be adjusted out, but it made me wonder what was going on. I then read that Campy places a .13mm wider cog between 6 and 7. I have not experimented with a wider spacer but it does make me wonder.

Now I plan on trying a Shiftmate using the Campy shifter/derailleur to see which one works the best (The shiftmate has not arrived yet. My question is, should I still use a wider spacer between 6 and 7. I figured the Shiftmate would reduce the pull length by about 5% for the Shimano spacers, so I figure I would add a .12 wider spacer.

Has anyone heard of this wider spacer with campy 10 speeds? Does it sound like it's worth the tweak to see if it's better. I know we're talking very small numbers here, but the difference between shifters and cassettes of different brands is often about .2mm and they are not comparable. Is there anyone else out there that deals with such minutia?

DaveSSS 

If you have Campy 10 shifters and RD, then you should try to get the cog spacing matched to a Campy cassette. There is a .15mm thicker spacer used between cogs 6 and 7, which is shown on the spare parts diagram that I've linked. Look at the Centaur cassette.

https://www.campagnolo.com/repository...s07_B-0407.pdf

I assume that the Miche cogs are Shimano thickness, 1.6mm and not Campy thickness, 1.75mm. That would require 2.55mm spacers instead of 2.4mm to get Campy cog spacing of 4.15mm.

Miche cogs are not known for great shifting, so don't expect the setup to shift like a Campy cassette.

onespeedbiker

The Miche cogs are thicker at the base, so the spacers are thinner. For the Campy spacing of 4.1 (2.4 spacers), Miche uses 2.26 spacers and for Shimano 3.9 spacing it uses 2.1mm spacers.

Saying this I put on a 2.4mm (2.26 + .13) spacer between the 6 and 7 cogs (replaced the 2.26 spacer) with the other Miche campy spacers and the shifitng was noticeably better, so apparently there is a point to this.

What I am wondering is where does this extra .13 b/t 6 and 6 come from? When I used the hubub cable routing (Campy 10 speed shifters with a Shimano 9 speed cassette and derailleur, there was no indication that the spacing was off, so I am wondering if it is somehow built into the Campy derailleur.

DaveSSS 

Both Campy and Shimano shifters use nonuniform cable pulls to produce relatively uniform movement of the RD. I've measured Campy 10 cable pulls and got 2.5mm five times, 3mm twice and 3.5mm twice. My measuring accuracy was limited to .01 inch or .25mm, so there could be other subtle differences in the pulls, that would require more accurate equipment to measure. An increase of .15mm is only the thickness of two pieces of paper, so it's not much.

onespeedbiker

Yet in this case is was enough to stop the 7 cog from trying to pick-up the chain when I shifted onto the 6 cog. It would rattle for a revolution and then settle in. I had to back off on the adjuster quite a bit to stop this, leaving just enough to shift from the first to second cog. Now, with a 2 sheets paper wider cog, the chain has calmed down when on the 6th cog. I not trying to be sarcastic, I am agreeing with you that is an amazingly small amount of added width that seems to have made the difference.