Maximum cog/capacity of Campagnolo 10?

[oliver1850]

I was discussing this with a forum member who wants to run C10 shifters and a 32 large cog. He's going to be using a Shimano FH, so a conversion cassette will be needed.

I put the 25/28/32/36 cluster from a PG1050 together with the 12-21 cogs from an AC conversion cassette, along with a Centaur 10 long cage RD, to see what it would shift. I was a bit surprised to find that it handled the 36 cog seemingly without trouble. There was a bit of hesitation on the downshift on one cog in the AC portion, but that could be overcome by shifting a bit more aggresively. All the upshifts were fine, and there was no rattling in any cog. I used the 9 speed chain that was on the frame for the test. I'm not sure if a 10 speed chain would affect the shifting.

The frame had a 32/44 crank, so I didn't push total capacity. Campy rated the long cage at 39, and I was only using 36. It appears that this setup would work with either a 39/53 or 36/50, and possibly with a 34/50.

I'm wondering if a PG1050 with slightly thicker spacers in the loose cog portion wouldn't work pretty well. As far as I know, there isn't a conversion cassette available with a cog any bigger than IRD's 12-28.

Is anyone running something like this?

[christian]

Next-level rocket science, this. I'm going to stick to the kiddie pool in the other thread. Good luck. (If there's anyone who can pull this off, it's you, but I'm surprised the derailleur doesn't rub on the largest sprocket - in other words, I'd be less worried about the capacity and more about the derailleur geometry.)

[oliver1850]

Largest cog size was my main question too, but it seems to be able to handle the 36. Campy only rated them for a 29 cog, as that was the biggest they sold at the time. I may put it on a bike that's ready to ride and try it out.

[audiisaac]

Bicycle Tricycle just tried this out on his Tournsol and it works well, I think that the build is in the gallery.

[Ralph]

I'm using a Campy 30-42-52 and 13-30 with med cage on one of my bikes with normal length derailleur tab (it's a custom steel frame), and the only cog combination that doesn't work is little to little. So basically my medium cage is working over 14-30 and 30-42-52 or 38 teeth total. More than it's rating. So not surprised a long cage will work beyond it's rating also. And also mine not bumping on the 30-30 shift....but 30 is all it will do well. And this is with a late 9's Campy Centaur medium cage RD used in a 10's system.

As you also know....when using a double, and a shorter chain than a triple, the small chainring pulls the RD cage around so that a much larger rear cog can be used than if using a triple. Not sure the upper limit, but not surprised a 32 or 34 would work. Am surprised a bit a 36 cog cassette would shift. Maybe RD tab kinda long on that bike.

[oliver1850]

38 is 2 more than the medium cage is rated at. If the long is rated as conservitively, that would give it 41 in practice.

thanks Isaac, I'll look it up.

(Looks like he's running a 32 cog with a medium cage and friction shifters. Good to know, though.) http://forums.thepaceline.net/showthread.php?t=86638

[Ahneida Ride]

Running 2002 10 speed Campy Record ... Triple FD and LC RD.

Crank = TA Zephyr 22/36/48

13/29 cassette

Shifts well indeed, no issues

[christian]

Ahneida - so you can go 48-29 without ripping the derailleur off and 22-13 without droop? So aggressively, we're saying 42 teeth capacity for the long cage?

That's interesting. Maybe not quite as interesting as the cage geometry allowing a 34, but pretty interesting in its own right.

[Dave]

A Campy 10 long cage should be rated to handle a 52/42/30 with a 12-29, which is 39T of wrap. What is often overlooked is that as much as 3T of wrap can be lost with the worst case chainstay length. Campy must assume the worst case, so it would have a 42T wrap.

[oliver1850]

I put the wheel with the Frankensette on my CAADX, which has a 30/42/52 crank. Again, didn't take the time to change the chain, but it was OK from small/small to the 52 with the 28 cog. With a longer chain, I think it would handle the 32, but probably not the 36 without going totally slack in more than a couple small cogs. So today I rode it at 38 total, and think it will go to 42 with a longer chain. Pic is in the 30/12 combination.

Next step is to play with an M10 cassette with the large cogs from the SRAM, and see if I can get it working a bit better than with the AC.

[Ahneida Ride]

Ahneida - so you can go 48-29 without ripping the derailleur off and 22-13 without droop? So aggressively, we're saying 42 teeth capacity for the long cage?

That's interesting. Maybe not quite as interesting as the cage geometry allowing a 34, but pretty interesting in its own right.

Yes ..... I can ride in 48-29 AND 22-13 ..... I've done both by accident
many times.

Shifts better with the 22 ring then with a 24 ring. Strange eh ?

But then I have a Long Cage RD.

More images here http://forums.thepaceline.net/showthread.php?t=30993



http://forums.thepaceline.net/attachment.php?attachmentid=104021&d=1350316887

[oliver1850]

I found that the 12-36 was too much wrap for the Centaur long cage with 22 tooth differential in the front. I made up another cassette using the 3 big cogs from a PG1050 11-32 with the other 7 from an M10. I rode this setup 50 miles on Thursday - I could use all the gear combinations and it worked pretty well. The shifting isn't as fast as with a C10 cassette, but I wouldn't hesitate to use it if I needed the 32 for a particular ride or event. This Rocky Mountain frame does have a hanger that's quite a bit longer than the Cannondale's, so there are probably frames that aren't compatible with the 42 T wrap.