Just Playing around with Campy 10 Med Cage

[Ralph]

The forum gets a question pretty regularly about using a Campy short cage rear derailleur on a cassete and crank combo a little beyond it's advertised capacity. And....it usually will work OK with some careful tuning of chain length and "B" screw. So thought I would do the opposite. Install a Campy med cage on a bike where short cage was working fine. I sometimes have a triple on one of my bikes, with a med cage RD, and just wondered if there was any downside to leaving the med cage on there all the time, even when I didn't need to use one after converting it back to double crankset.

So....took off the Centaur short cage, and put on Centaur med cage. Didn't touch chain. Big to big tightness stayed close to same, large cog clearance increased, but without adding a couple links, capacity didn't increase much. Shifting was great. Then added a couple links to chain using another quick link which gave the added capacity. Now pulley wheel looks like in more normal position. With 39-52 in front, put on a 12-30....worked great. Used it as a 13-30 (the 13-19 from a 13-29 and the 21-30 from the 12-30)....shifted fine just like short cage. 13-29.....shifted perfect, about same as short cage RD. Rode it some with a 13-26 (what I usually ride with around here)....shifted perfect, like a short cage. Put on a 14-23.....here I had a couple issues, upper pulley wheel a littls far from cogs, so shifting was a little sloppy with B screw all the way in, but if I were to take back out those added links, imagine shifting w/b same as short cage. I may take those links back out because I'm liking the 14-23 and 39-52 combo for riding around my home area. With a tail wind, I can pedal up to about 28 MPH with a 52-14 when my old riding buddies and I sprint against each other, usually at least once on about every ride. Funny sight....us old guys in a spint on a deserted slightly down hill area of our regular ride.

So I'm going to leave the med cage on there. Am having a new steel frame (with Eve fork) being built, will run it with a double front, and think I'll just put a Campy Chorus Carbon med cage on it (have a new one in box), so I can run any cassete (Even IRD with 32 large cog) and crank combo I wish without changing RD. Just FD, chain length, and crankset if doing a triple....simple). I see no downside in performance at all with med cage RD.....unless the looks of that slight increase in cage length bothers some. I do think, where you are pushing the limits of what a short cage will do, but where it's working Ok, the med cage does shift better......like you would assume I guess. Also will take up the slack better on a FD down shift....if chain a tad slack with short cage.

Sorry to bore you guys with this stuff.....some of us old retired guys just like to play with our bike parts. Have too much play time I guess.

[Brian Cdn]

Ralph.

Great stuff here.

Thanks for taking the time to write this and share it.

B

[Ssalmon]

Very interesting, I had bad luck when I ran a med cage centaur rear der on my cross bike which was 40x 12-25. The shifting was never crisp like on my road bike, and once I changed it out to a short cage it worked much better. The interesting thing about the short and med cage is that campy claims the short cage can handle a 29, but the med cage can only handle a 26...

[Formulasaab]

My best shifting bike is old-shape Chorus carbon 10sp, medium cage, and a 13-30 cassette. It feels ever so slightly crisper than my all alloy 10sp Chorus bike with a short cage and 11-25.

[Ralph]

You have to adjust B screw and chain length so that upper pulley is as close as practical to cogs you want to shift to. With single front CR and a 12-25, that's difficult to do with med cage.....I had same problem with a 14-23 and double front.

I'm not proposing folks chuck their short cages for med ages, I'm just interested in not changing any more parts than I have too when I ride in different terrains and travel where there's steep climbing. For me....for most cassettes and chain ring combo's, I can't tell much difference in shifting quality, and I'm picky about stuff like that. But do admit to having a good supply of chains and KMC links (and shift cables as I mess them up) to work these issues out. I also like to wrench on my bikes and change things around. So just reporting some playing with parts.

[Ssalmon]

Have you done similar research with cables & housing combinations. Also with different chain brands?

[Ralph]

I wouldn't call an old guy playing around with parts research.

I use either Campy or the higher end Jagwire Race cables and lubed housing. See no point in using anything else. Jagwire makes some cheap stuff also...avoid non stainless cables and cheap housing. Have used some Shimano 4 MM housing. it's good. Am sure others make good stuff also.

All my bikes are Campy 10 speed. In the past, I always used Veloce chains with KMC quick links. The links made for Campy 10 chains....(KMC CR) link. Stopped doing that when I noticed my Park chain checker would show the new Veloce chain with a .25 stretch, and if measured over some links that included the new quick link, the chain checker would show almost a .5 stretch.....this for a new chain. So that tells me the quick link is not a perfect fit (even though it works well).

Switched over to KMC chain.....with their quick link, and my Park chain checker shows less than .25 stretch on a new chain, and it measures the same whether over chain with quick link or without quick link. So I just figure if I'm going to use a KMC quick link, might as well use their chain also. BTW....I can't tell any difference in how it shifts or wears VS Campy. And....I don't usually take a chain off and clean it. Maybe once in chain life, maybe not. Don't want to remove any original greese. I wipe it down once in a while, and lube it with small drops of motor oil, then wipe off all I can. Ride it once, and wipe it down some more. Have used other packaged stuff, but roads are fairly clean around here, no winter sand, and oil works fine for me. My chains last a long time also before showing much stretch. I throw them away early at .75 stretch ....around 4000 miles or so. Chain lubes work also, just cost a lot more. And I don't think works any better for me. But I do have an oil can that despenses oil in small drops. My cassettes last a long long time.

Don't know how scientific all this is. It's just what I do.