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Campy - Shimano Drivetrain compatibility(8 posts)

Campy - Shimano Drivetrain compatibilityacp
Sep 23, 2002 7:46 AM
If I use a Shimano cassette and Shimano chain with a Campy cranks/chainring and a Campy rear deraileur will I experience shifting problems? The whole system would be 9 speed.

Also, would a Shimano 9 speed chain have problems with a Campy 10 speed deraileur and chainrings?
could be improved...C-40
Sep 23, 2002 8:24 AM
I assume that you will be using campy shifters with that campy derailleur. That is a must.

The shifting will be improved if you get a special cassette from excel sports that has campy 9 speed spacing. The shimano chain should work fine.

Personally, I'd spend a few extra bucks and convert the shifters to 10 speed (if they are existing) or buy 10 speed shifters if they will be new. Excel Sports also has a 10 speed cassette that will fit on a shimano hub. Then you need to use a 10 speed chain to complete a 10 speed drivetrain.

The following describes why a shimano 9 cassette with an otherwise campy drivetrain doesn't work so hot:

Campy cog spacing is 4.55mm and Shimnao is 4.32mm. The difference is 5%, which accumulates to a derailleur positioning error of 20-40%, depending on how well the derailleur is adjusted. To get the best shifting, the derailleur must be centered on the middle cog to distribute the 40% error equally between up shift and down shifts.
could be improved, but not by much...dzrider
Sep 23, 2002 10:55 AM
I have an old set of wheels, Mavic Open 4CD, on Ultegra hubs. I put a 9 sp 12-27 Shimano Cassette on it and tried it with my Chorus 9sp shifters and Racing-T derailleur. I have to tighten both limit screws about 1/4 turn and it shifts fine. Sometimes when I shift up to the 2nd largest cog I have to tap the thumb lever to quiet the chain, but that is the only problem and I'm willing to live with it.
No problems here eitherjzinckgra
Sep 23, 2002 11:42 AM
I've got Chorus 9 speed (last years shifters and rear derailleur) with a DA 12x23 cassette and have had no problems whatsoever. In fact I just ordered a new set of wheels and went with a shimano hub body, as I will be transferring the cassette from my current wheels to these. I'll probably have to readjust the limit screws on the derailleur though.
to each his own...C-40
Sep 23, 2002 4:02 PM
Sure it will shift, but with the top and bottom cogs misaligned 20% relative to the derailleur and the rest misaligned 5-15%, it's got to be noisier than normal and component life can't possibly be as good with the sideways forces induced by the mismatch. Personally, I'd use all campy parts or at least use cogs with the proper spacing.
no probs here...slomo
Sep 23, 2002 11:07 PM
...i haven't noticed any increase in drivetran noise. i've been running dura ace shifters/rr der. with camy 9 sp cassette and it works very, very well, all nine cogs. i would say hardly a decline in performance over my full campy10 equipped bike.
re: Interesting...Mike Prince
Sep 24, 2002 5:47 AM
Not to start anything here, but this seems to be a recurring theme with Shimano and Campy 9 speed "compatibility". Everytime (do an archive search and you will see) someone asks a question similar to the source of this discussion, out of the woodwork comes a mathematical "formula" that says no way, it can't work. Immediately followed up by a multitude of non-mathemeticians that do it and have zero problems in real life.

Again, not trying to start a war, but the striking difference between the theoretical calculations and the real life experience of those who actually try it are interesting. In some ways a credit to both companies as their gear is a bit more flexible than the engineer-types are willing to admit. Just my idle observations.
the number prove why it works...C-40
Sep 24, 2002 6:52 PM
Most folks spend most of their time in the middle four or five cogs, where the derailleur positioning error is the least, if it's adjusted properly. The numbers prove that.

They also demostrate the need to use an entirely different technique for adjusting the derailleur. Normally, once enough tension is reached to get a decent shift from the 1st to 2nd cog, all the other shifts will work too. Not so with a bastard setup. If you adjust in the normal manner, the derailleur will be overshifting badly by the 6th or 7th shift and trying to jump into the spokes on the 8th, due to the large amount of overshifting from the campy derailleur.

The limit screws must be used to contain some of the overshifting and the shift cable has to be tensioned to produce the best shifting around the middle cog. Sometimes is pays to look at the numbers. They will explain why the shifting adjustment works weird.