Campy 10 sp, 12/30

[Birddog]

Will I be able to run this cassette with a reg(short cage) rear derailleur? I know about the hazards of cross chaining, I just need it for some extreme climbing. I assume I might need to have a chain with an extra link too.It will be used with a 50/34 compact. Real world experience?

[saab2000]

I use a 13/29 with regular cranks with no problem. The compact might cause more trouble but I don't think so. My 13/29 works perfectly with a regular Centaur derailleur.

[druptight]

I don't think your rear derailleur will be able to eat up that much chain. I run a 12-27 on a standard centaur rear derailleur with a compact centaur crankset and it's at about the limit of how much chain wrap is possible. 13-29 I understand is possible, and that's one more tooth of wrap - but 12-30 is 2 more than 13-29 and 3 more than my 12-27. You might be pushing the limits.

[oldpotatoe]

Will I be able to run this cassette with a reg(short cage) rear derailleur? I know about the hazards of cross chaining, I just need it for some extreme climbing. I assume I might need to have a chain with an extra link too.It will be used with a 50/34 compact. Real world experience?

As soon as these were available we installed onto a few 10s Campagnolo systems and even w/o changing chain length, no problemo.

CT, shift cage, 12-30, 2009 and 2013 Centaur and Veloce stuff. Before that they were 13-29..

[christian]

Published capacity of Campagnolo derailleurs is:

Short - Maximum Cassette Cog is 26 and Total Capacity is 27
Medium - Maximum Cassette Cog is 29 and Total Capacity is 36
Long - Maximum Cassette Cog is 29 and Total Capacity is 39

But in theory, at least, each of these can be stretched a bit.

In your scenario, you've got a 16 tooth difference in the front and a 18 tooth difference in the rear for a total capacity required of 34.

I don't think there's any way the short cage will handle that. With a 50-36 front, you'd shift into definite-maybe territory.

[druptight]

And that's with a compact front chainring set Peter?

[Dave]

If you've got a relatively late model RD, it will work because Campy does not make a medium cage 10 speed RD anymore. The 12-30 cassette is new and works with the newer short cage RDs.

Clearance between the upper jockey pulley and largest cog is another issue. Campy improved that with recent changes to the RD. An older RD might not have enough B screw travel to clear a 30T.

With an older RD, the only way to know for sure is to install the 12-30 and set the chain to the minimum length using the big/big plus one inch method.

Just because one bike works with this combo does not mean that all will. Chainstay length variations can cause up to a 3T loss of wrap capacity.

Whether this works can also depend on whether you're willing to have the chain hang loose in the little ring and one or more of the smallest cogs. If that happens, with the chain at the minimum length, then the RDs wrap capacity has been exceeded.

One other way to predict whether this will work is to apply the rigorous chain length formula from the Park Tool website. You will need an exact chainstay length. If the formula suggests a length just over 53 inches (for example), it means that you'll need a 54 inch chain length. If the chain hangs loose in the little/little with that length, then you know there's not enough wrap capacity.

[oldpotatoe]

And that's with a compact front chainring set Peter?

Correct..we haven't sold a full sized crank for a long time..compact on all the demo bikes as well.

[druptight]

If you've got a relatively late model RD, it will work because Campy does not make a medium cage 10 speed RD anymore. The 12-30 cassette is new and works with the newer short cage RDs.

Clearance between the upper jockey pulley and largest cog is another issue. Campy improved that with recent changes to the RD. An older RD might not have enough B screw travel to clear a 30T.

Maybe this is my issue, I'm working with a 2007 Centaur Short cage that lists 26 tooth wrap capacity. At 50-34 and 12-27 I'm pushing the limits at 29 teeth. I can tell you almost certainly that I could not run a 12-30. When I'm in big/big right now my chain is stretched pretty tightly (which I try to avoid), but when I tried to add a link to loosen it up, the RD couldn't take up the slack in a small/small scenario.

[donevwil]

It will work if you don't cross-chain 50-30, and run the chain a link looser than a normal setup. It does, however, really yank the deraillleur in most big-biggish gears, something that doesn't scream longevity. I ran my wifes bike like this for a few months until I could find a medium cage. The med cage yields much more even chain tension at the extremes allowing higher tension and less chain slap in the small-small range.

[Dromen]

sorry meant to start new thread.

[Vientomas]

50/34 with 13-29 and Record carbon rear derailleur. This works for me. I don't use the 50-29 combo. The "B screw" is at the limit with a 29.

[Ralph]

You can find out easy enough. Put 12-30 on and see. If you don't have enough chain, put on a new chain using all the links. Take out some until the big to big will wrap. Now see if the 34 and 30 will work.....pulley wheels not bumping too much on 30 cog. Screw B screw all the way out if necessary (or in, dependng on model of RD). If everything works OK, and little to little too slack....that doesn't matter.....you don't use that anyway. Some frames it may not work. New versions Short cage RD will likely work easier than mid 2000's models.

[Birddog]

Thanks for all the replies. I will give it a try tonight on the workstand and if it works there will try it out tomorrow. I'll post results.

[oldpotatoe]

You can find out easy enough. Put 12-30 on and see. If you don't have enough chain, put on a new chain using all the links. Take out some until the big to big will wrap. Now see if the 34 and 30 will work.....pulley wheels not bumping too much on 30 cog. Screw B screw all the way out if necessary (or in, dependng on model of RD). If everything works OK, and little to little too slack....that doesn't matter.....you don't use that anyway. Some frames it may not work. New versions Short cage RD will likely work easier than mid 2000's models.

Yep, this is key and what we do when something new and 'whizbang' comes out. Do all the chain wrap, max tooth calculations you want but actually trying it is the actual answer for your bike, your wheels, your setup.

[Birddog]

Went on a 50 mile ride with the setup. No changes necessary. It even works cross chained big to big but I sure wouldn't recommend doing that as a habit.

[oldpotatoe]

Went on a 50 mile ride with the setup. No changes necessary. It even works cross chained big to big but I sure wouldn't recommend doing that as a habit.

Taaa-daaa