jeirvine 

I have done the Shimergo thing on a few bikes and it works a charm: 8sp Ergo shifters and Campy RD shifting a Shimano-spaced 7sp cluster.

I am thinking of trying the opposite, and wonder if others have had success: 7sp Shimano DT Shifters + RD shifting a Campy 8 sp cassette. I think the shifter indents would be correct, and then the 8th should work via RD stop. I have a lot of the parts to give it a shot - an orphan Mirage rear wheel and 105 7sp shifters/RD - but I thought I'd ask first.

Thanks,
-J

ThermionicScott 

I'd be surprised if it didn't work!

dddd

You will only find an eighth click in certain of Shimano's very old 7s thumb shifters, I don't think that any of Shimano's 7s road shifters can effect a full 8 indexed positions in any way.

And there is a difference in the cog spacing also, such that the 2nd and 3rd-smallest cogs in a Shimano 7s freewheel or cassette are separated by a 3.3mm spacer, while the rest of the cog spacers are only 3.1mm, which is enough of a difference to make combining Shimano 7s with Campag 8s more sensitive to cable adjustment that affects the indexing over the entire range. But spacers can be changed. This has been a minor issue when using Campag 8s shifters/derailers with SIS-7 freewheels and cassettes.

Lastly, if the 2nd to-last cog on the Campag 8s freewheel is as far as the Shimano 7s shifter will go, then the limit screw will be the indexing "decider" on that cog, and not the cable/indexing, and so indexing should be right about spot-on!

onespeedbiker

There is a web site dedicated to this "Shimergo"https://www.ctc.org.uk/cyclists-library/components/transmission-gears/derailleur-gears/shimergo if you look below at one of the charts, you can see you current setup is shown to work. If you follow "Campag 8" to "Old Campag" it says with will work with S(himano)7/C(ampy)8.





Further another graph shows that (and it is common knowledge) that Shimano 7 speed and Campagnolo 8 speed have the same cassette spacing, so as long as you use the same brand shifter and rear derailleur if should work. The only caveat is Campy 8 speed (and old 9 speed) have a different geometry so this will only work with Campy 8 speed shifters and derailleurs.

verktyg 

4 things that affect index shifting are the amount of travel each click in the shifter makes, the cog spacing, chain width and most importantly the side to side movement of the upper pulley on the rear derailleur.

I prefer Shimano cassettes because I have a ton of them, they're available in a far wider range and variety of cog styles plus they're less than half the price of Campy cassettes.

The side float on the top pulley drastically assists in shifting. I use indexing RDs with friction levers on a number of my bikes and they work just like STI levers.
I even have some Simplex RDs that I've sanded down the plastic pulleys so that they have some side float. They index perfectly with 7 & 8 speed Shimano cassettes and levers.

Lack of pulley float was the main reason Campy Synchro Indexing never worked or never worked well!

Sheldon Brown RIP has a page on cassette compatibility (scroll down to the bottom):

Shimano Cassettes & Freehubs


verktyg

Chas.