Technical FAQ: 10/11-speed compatibility

Questions on drivetrain compatibility and reader feedback on cleaning shift levers, oval chainrings, and more

Dear Lennard,
I was reading the comments in a recent column about a rider switching from 10- to 11-speed when his shifter broke. This leads me to the question. Which recent 10-speed road wheels are compatible with SRAM/Shimano 11-speed? I know that’s a large topic, but I was thinking primarily of popular, high-end carbon wheels like Zipp Firecrests, Mavic Ksyriums/Cosmics, Reynolds, and Bontrager.
— Glen

Dear Glen,
I don’t know if Mavic had a crystal ball years ago, but Mavic 9/10-speed wheels are 11-speed compatible. That’s because its Shimano/SRAM-compatible freehub bodies have for many years been wider that those of other hub manufacturers, and in order to put a 9/10-speed cassette on one, you were required to put a (supplied) spacer behind the cogs. This was amazing foresight or plain old dumb luck.

As far as I know, no other 10-speed Shimano/SRAM-compatible freehub bodies are 11-speed compatible without modification (as I did here).

However, all Campagnolo-compatible 9/10-speed freehub bodies also are compatible with Campagnolo 11-speed cassettes. And, as I’ve said before, there is 100 percent shifting compatibility between 11-speed cassettes. In other words, Shimano, SRAM, and Campagnolo 11-speed cassettes work just fine on each others’ drivetrains. So, one way to use an old 10-speed wheel with an 11-speed drivetrain is to install a Campagnolo freehub body and Campagnolo 11-speed cassette on it.
― Lennard

Dear Lennard,
I was reading your Technical FAQ on drivetrain compatibility for 10- and 11-speed yesterday (sadly I consulted it after I started building my new bike). I had the same thoughts as Bruce about using an Ultegra RD-6800 derailleur with 10-speed shifters so that I could use a larger rear cog (for the old man and mountains reason).

Since I used various rear derailleurs in the past, I made the assumption that the RD-6800 would have the same cable pull ratio as the 5700 and 6700 derailleurs. But when I fitted the RD-6800, I found that, when using 10-speed shifters, it only shifted between 8.5 and 9 cogs instead of 10.

So it does look like Shimano have changed the cable pull ratio for the 11-speed rear derailleurs.
— Jeremy

Dear Jeremy,
Yes, that is correct. Shimano’s mechanical road 11-speed cable stroke is a road version of 10-speed Dynasys for mountain bikes (which has a longer cable pull per millimeter of derailleur movement than 9-speed MTB shifters).

One possible solution is to use a Shimano Ultegra RD-6700 long-cage GS version to get the range you want, or even an SS cage if you have a modern carbon frame with vertical dropouts with a Shimano XT 11-32 10-speed cassette and your 10-speed shifters. This is not a Shimano-approved setup, but it will work fine.

1. The GS cage is basically interchangeable between RD-6700 and RD-6800.

2. The 28T max rear cog capacity of all Shimano road rear derailleurs is based on horizontal, short Campy dropouts of the early 1980s.

3. The key to make it work is not adding chain links. Use the shortest possible big/big chain combination that doesn’t explode so that the small/small combination has no slack and the inner front chainring to the 32T rear combinations doesn’t interfere. Note there is also a 12-30 Ultegra cassette that easily works on modern bikes with the B-Tension screw turned all the way in.

4. Vertical-dropout carbon road bikes generally shift well with the XT 11-34 10-speed cassette, but you need to add two links, use the GS long cage, and reverse the B-Tension screw. This definitely is a case-by-case modification.
― Lennard

Dear Lennard,
I read through a lot of the articles on 11/10-speed compatibility, but I can’t find the answer to my question. I currently have SRAM Force 10-speed. I have 11-speed compatible wheels. I would like to upgrade but was wondering, do I have to upgrade the crankset and brakes? Can a six-piece upgrade kit (two shifters, F/R derailleurs, cassette, and chain) work just as well?
— Stephen

Dear Stephen,
Yes, that will work fine. You can also keep your 10-speed rear derailleur. The 10-speed front derailleur will also work, but the 11-speed version is a big improvement, and that’s not a hugely expensive part.
― Lennard

Feedback on road brakes FAQ:

Dear Lennard,
Just a thought on Matthew’s recent question on his 7800 levers. He mentioned that they were “packing.” I assumed he meant that they weren’t fully clicking into position. Rather than replacing the levers, he might try to pull the hoods off and soak them in degreaser (I like Park Tool’s Chainbrite) for a few days. After that, work a light lubricant into them (like Triflow or ProGold). I’ve been able to rescue dozens of older Shimano levers that way.
— Matthew

Regarding oval chainrings, and other gearing questions:

Dear Lennard
I’m surprised no one has sent you this article (PDF) yet. I’m a cyclist and a researcher, and while I use oval chainrings (Qrings), I’ve completely accepted that they’re mostly for comfort, not power output. Whether the small changes in power output result in physiological changes over a 40km, I think remains to be seen.

I would caution your readers to look at who’s funding these studies claiming “10 percent power increases” and the like.
— Amos

Regarding chamois irritation related to soaps:

Dear Lennard,
Following up on this past post about rashes from soap and wipes, I’ve used Dawn dish soap on my body with great effect. Much less drying and irritation, and it leaves behind the body’s natural oils. I got the idea from my uncle (we are both strength coaches and cyclists) who was experiencing negative effects of body wash, and thought to try Dawn since it is used for animal rescue (cleans foreign dirt, grime and oils, leaves natural body oil)
— Chris