Technical FAQ: Mixing and matching 10- and 11-speed Shimano and Campagnolo drivetrains

This week we continue to examine drivetrain cross-compatibility, with questions from a couple of riders planning for exotic outings, as well as a follow-up on Campagnolo and Shimano 11-speed mashups.

A smaller granny gear for 11-speed?

Dear Lennard,
There is no way to learn upcoming news about gear up here in Juneau, Alaska.
For some years I used my old triple Campy stuff, especially for
climbing the steepest in the Dolomites like the Tre Cime di Lavaredo
and the Mortirolo. With some creative sourcing, I managed to find a 10-speed setup with highest of 53×11 and lowest gear 28×30. Great for 20 percent
 ramps at my age of 66 years.

Now my new Eriksen needs a new drivetrain.
 I hope to find the equivalent low gearing using a compact, but it seems 
that no one makes 11-speed clusters with a 34-tooth cog. Ten-speed 
Shimano XT can work, I understand. But what better use of that 
eleventh cog than a wider range? The pro peloton doesn’t need such, but
some of us do. 
Is there any chance that a manufacturer will come out with an 11-speed, 11-34 cluster anytime soon? I am thinking that the Ultegra GS 
rear derailleur could be convinced to shift to a 34, or maybe even higher, 
like a 36?

— Eric

Dear Eric,
There is no SRAM or Shimano 11-speed cogset that will fit your freehub body that has a cog larger than 32T. In answer to your question, I suppose there is a chance, but I’ve heard of nothing on the wind. SRAM of course makes 1×11 MTB drivetrains, but the 11-speed cogsets incorporated into them require an XD driver body, which of course also means a disc-brake hub with at least 135mm of rear axle spacing. Campagnolo cogs don’t fit your freehub and also don’t come larger than 32T.

And actually, contrary to what I think you were alluding to, 10-speed
Shimano XT won’t actually work unless you do something to adjust for difference in cable pull between Shimano 10-speed road and MTB shifters. Shimano 10-speed actuation ratios are different on its road and mountain rear derailleurs. I suppose you could still put a 10-speed 11-34 or maybe even 11-36 MTB cogset on there and try and boost your long-cage road rear derailleur with the b-screw turned around.

You can also set up a SRAM 2×10 drivetrain using SRAM road shifters and any 10-speed road crank. Then for your trips to the Dolomites, you could swap to an 11-36 SRAM 10-speed MTB cassette and an X0 rear derailleur or something similar. It would probably be smart to use a chain specific for each setup, so that when you swap the cassette, swap to the corresponding chain so that it’s the right length.

I ran this by SRAM MTB product manager Chris Hilton, who said, “As you know, a SRAM road and MTB 10-speed shifter share the same exact actuation, making them cross-compatible with MTB and road. Be aware though, every bike frame is different. Not knowing the exact specifications, it’s hard to determine the complete compatibility. I would make sure I did a thorough evaluation on my bike before I threw a bunch of parts on my bike and headed to Italy.”
― Lennard

Can Shimano 105 and XT work together?

Dear Lennard,
I noticed with interest your columns on Frankenstein drivetrains.

I am building a Ti touring bike for mountain touring on the Tibetan Plateau. I am taking the wheels and Shimano 105 10-speed group off my ’cross bike (a five-year-old Trek X1). However, the Bontrager ’cross crankset does not provide enough gearing for where I’m going. So, I purchased an XT 10-speed double (40-28) crankset with the HG-X chain to go with it. However, I have been reading that this chain will be incompatible with the existing 105 cassette (11-28) and derailleur, and conversely the existing 105 chain also won’t work with the XT rings. Is this right?

As I have been considering alternatives, I am thinking that if this does not work, I will instead leave the ’cross crank where it is but go with a bigger cassette on the back and a mountain bike derailleur. However, also reading that the 105 control levers will not work with a 10-speed MTB derailleur, the pull ratios are different. Argh. Could I use a nine-speed cassette/derailleur with that 10-speed lever, and if so, where does the 10th “click” go?
— Tom

Dear Tom,
Okay. A lot of questions here. First off, I would not worry much about compatibility with the XT crank and the asymmetrical CN-5701 105 10-speed chain, or the asymmetrical (“directional”) CN-HG94 XT 10-speed chain with the 11-28 105 cassette and rear derailleur. For a number of years, I had asymmetrical Shimano 10-speed road chains on the Dura-Ace 7800 drivetrain of my travel bike with a master link in them and a SRAM cogset. Sometimes in dim light in an annex of an airport or train station, I installed the chain backward and rode it that way. While shifting is not ideal, it was never bad enough that I felt compelled to stop and turn the chain around before completing the ride. And that’s the worst-case scenario — installed backwards. If you install either one of those chains in the correct direction, shifting will be acceptable.

You can also just get a symmetrical 10-speed chain. For instance, Wippermann makes no asymmetrical chains, yet it advertises that its 10-speed chains work on all 10-speed drivetrains, and that has been my experience.

As for your other questions, I doubt you’ll even have to entertain them, because I think you’ll find that your shifting is good enough for your Tibetan Plateau adventure. When you get back to flatter terrain, you can always go back to a traditional setup.

It is correct that a Shimano 10-speed MTB rear derailleur will not work with a Shimano 10-speed road shifter. And you definitely cannot expect a 10-speed shifter to work with a nine-speed cassette. However, you can use a 10-speed cassette and 9-speed Shimano MTB rear derailleur with your 10-speed 105 shifter (and a 10-speed chain).
― Lennard

What adjustments are necessary with 10- and 11-speed wheels?

Dear Lennard,
Recently I read this in your column and found it helpful as I installed a 10-speed cassette on my new 11-speed wheels:

And in case any of you were wondering, if you have a 10-speed Shimano or SRAM system and buy a wheelset now, you can still run 10-speed cogs on that wheel. To put a 10-speed cogset on an 11-speed freehub, you just put a spacer behind the largest cog. Many 11-speed wheels come with this spacer.

I have done this and all seems in working order. However, I’m wondering if any rear derailleur adjustment is necessary to ensure smooth shifting in this 10/11-speed hybrid. Thanks very much.
— Chris

Dear Chris,
Just the usual rear derailleur adjustments are all that is necessary.
― Lennard

Did I miss the Campy/Shimano follow up?

Dear Lennard,
Many months ago you wrote briefly that Shimano 11-speed and Campy 11-speed cassettes are interchangeable with a comment that you would have more on that to come. I’ve been reading and haven’t noticed any more, can you confirm that the two cassettes are interchangeable? I am curiously waiting to know if my DA9000 wheel will work on the Record 11 bike I am planning to build this year.

Thanks for your relentless compatibility answers.
— David

Dear David,
Yes, your DA9000 wheel with 11-speed DA9000 cogs will work on your Record 11 bike. Here is the follow-up article: “Compatibility hidden in plain sight”.
― Lennard