JunkYardBike

UPDATE BELOW

Campagnolo officially lists 27T as the max large cog size for the Racing T rear dérailleur. Has anyone tried a 30T? Or would I be better off using a 28T?

I'll be mating it to a Shimano 7 speed cassette. Not sure if that makes a difference, but it will need to clear a 30T earlier in its travel than it would with a Campy 8 speed cassette. I believe this Racing T dates to the 8 speed era of Campy.

Deanster04

Is the racing-T RD a long cage? If so it will work easily on a 29T Cassette. I have one on a 9 speed cassette. The short cage will work up to a 28T on an 8 speed campy wheel. I have both in my stable. I think that the limit is primarily for the short cage derailluer.

I found a campy Daytona Hub with a Shimano compatible hub body. I am going to try a Shimano or SRAM 11-32 cassette on the wheel with my 10 spd shifters. I will be using the wheel with my Record compact double crankset. Should be a interesting experiment. There is a small difference in the cog center to center spacing of 0.2mm. I may try and use 9 spd shifters if the 10 spd doesn't work and adjust the cassette spacers with a belt sander. What the heck.

JunkYardBike

Yes, it's the long cage version. Be sure to post your results with the 32T. I'm planning on running 8 speed ergos with a Shimano 7 speed cassette: a perfect spacing match.

acorn_user

The spacing on 7 (Shimano) and 8 (Campagnolo) are both 0.5mm I think, so they should work perfectly. IRD make Campagnolo cassettes that go up to 32t, so I think your experiment should work, although it might take some work.

I wish Campagnolo would come up with its own cogset and a touring triple. Ergo shifters would be great for a touring/audax bike. They don't even need to do much to get them out of their racing ghetto.

Road Fan

Some interesting possibilities!

How big a gear range do you need? 13-29 mated with 52-42-30 gets you a low-end of around 26.5 inches, just staying within nominal specs and no limit on combos. If you can extend the operation to a 24 sprocket and an 11-32, you get a low of 19.5. That's about as low as anything, and might (I can't really say!) be workable with some combo contstraints. Total wrap requirement is now 28+21=49 T, which is a challenge for any technology, save perhaps a friction Duopar.

With the 11-32, I would tend to reduce the big cog to 44 and the middle to something else, to minimize the wrap requirement and get back down to a top end of 104, but I really don't know if the chainwheels exist. I guess this is where Frankensystems come from!

Road Fan

Al1943

You'll probably be able to accomplish what you are trying to do but even though the spacing may be the same the Campy derailleur has a different throw ratio from the Shimano.

JunkYardBike

I should be okay, though, because I'm using Campy 8 speed shifters and Campy 8 speed RD.

HillRider

If anything Campy seems to be moving away from all triple cranksets. They dropped the road group (Record, Chorus, Centaur, etc.) triples and introduced a couple of triple specific groups that nobody seems to carry. Campy seems to think a Compact crank is low geared enough for anyone.

You can use Ergo shifters on an otherwise Shimano drivetrain by adding a Jtek shiftmate to correct for the cassette spacing differences. I'm using Record 10-speed Ergo's with a 9-speed Shimano cassette, rear derailleur and a 9-speed Ultegra triple crank with very satisfactory results with a Shiftmate for the rear shifting.

Al1943

Yeah, OK.

Deanster04

I purchased a couple of triple cranksets with 30/40/50 chain rings. I have a record with a 30/42/53 as well. For my cross bike I substituted a 26T front chain ring (T/A Speciaties) 74BCD and a 28T on my touring bike. Gets me the low gears I like. At 64 years I like the option of the lower gears. Instead of stopping to rest on one of the very long steep roads here in Colorado I simply drop down into what I call my "resting" gear and keep moving resting my legs. When I am feeling strong again I drop down on the rear cassette and roar off putting several hundred yards on my friends who stop and rest. I enjoy doing the Bicycle Tour of Colorado and hitting passes from 10.5K to 12.4K in five of the 6 days requires creativity at my age.
The T/A chainrings are a perfect substitute for the Campy triple and/or double chainrings. They have the ramps to help the shifting up. I will probably go to a 28/39/48 on the 11-32 experiment for my touring bike. Meanwhile I will be using it with a compact double 34/50.
A word of caution: the shifting on Campy is optimal using the 30T chainring. When you go to a 28T (53TCR) or 26T (50TCR) on the front you need to shift into the small chain ring early in the 3rd or 4th cog down or you can drop the chain. Just a slight inconvience. A way around this is the put a centaur Triple on a record or chorus triple BB. It shifts the chainline to the left and prevents the dropped chainring. If you have a Phil Wood BB you can shift the axel left and have the same effect. The Campagnolo design is very well done so when you change anything you usually need a work around.
By the way thanks for the tip on the 8spd. I have a C-Record Group that I might experiment with as well...one thing at a time...

HillRider

I have a Chorus Triple 10-speed crank with the standard 53/42/30 rings and I'm planning to swap the 30 for a 26T ring at the next overhaul. I've done this with numerous Shimano cranks and the results are very good. Shifting from the 26 to the 42 isn't super fast but I'm rarely in a rush for this shift anyway and I do have to anticipate the 42 to 26 shift.

I realize the Campy crank isn't going to be ideal with this arrangement but I have an N-Gear Jump Stop on the bike so spilling the chain shouldn't be a problem. Glad to know someone else has done this with a Campy crank.

JunkYardBike

So, I finally got around to setting the drivetrain up. What a headache! When in the triple's granny ring up front (it's a Veloce 52/42/30), even with the B-tension screw completely engaged, and the wheel as far forward in the drops as possible (unfortunately, they are short horizontal dropouts) the upper jockey wheel sandwiches the chain against the 30T cog. It does eventually shift on the workstand, but I'm afraid to try it on pavement.

When it's in the middle ring on the front, however, it shifts to the 30T smoothly.

Any thoughts on what's going on? Obviously, when in the middle ring up front, there is less chain slack, which appears to pull the jockey wheel forward and down. Seems to make a difference. I've sized the chain using the "big ring/big ring + 2 links" practice.

Oh, and I'm not sure the Campagnolo C9 chain likes the Shimano HG70 cassette. The chain is supposedly backwards compatible to Campy 8 speed, which I assume would make it okay for Shimano 7 speed HG cogs. But the chain sometimes shifts ever so slightly coming over the top of the cassette - which makes a racket in certain gear combination, but mostly 52 and the higher 3 or 4 cogs. I'm guessing it might cause chain slippage in actual use.

Al1943

Bummer. Have you tried shortening the chain one link? Also you may have better luck with a Shimano 8-speed chain (or equivalent).

Al

JunkYardBike

Just shortened the chain two links, and it seems to have done the trick. I'm just afraid of myself, as I happen to be a very careless with shifting (usually the byproduct of exhaustion).

The chain is still a bit clicky-clack happy, but it appears to have remedied some of the chain shifting problems.