Technical FAQ: Mixing SRAM and Shimano

Mixing SRAM and Shimano

Dear Lennard,
I’ve got a full SRAM Rival Hydro disc 1×11 set up on my ’cross bike but want to convert to Shimano shifting — I just find the small SRAM lever too fiddly with gloved hands in race conditions.

Do I need to change everything to convert to Shimano or can I just get new shifters? I think the cassette and chain are probably compatible but I guess I will need a new rear mech too? What about the calipers?
— Rob

Dear Rob,
You can keep your crank. You can also keep your cassette (if it’s 11-32 or smaller), chain, and chainrings, provided that they are not worn out. Everything else in your drivetrain and brakes must go, although you may keep your rear derailleur if you use the proper adaptor.

Most importantly, YOU CANNOT mix Shimano and SRAM hydraulic brake parts. It’s more than a performance issue — it’s a safety issue. Shimano brakes employ mineral oil as hydraulic fluid, whereas SRAM uses DOT brake fluid. Those are incompatible — one is insoluble in water, and the other is water soluble. So if you were to attach Shimano brake levers to SRAM calipers, the seals in the caliper would fail if you were to use Shimano fluid in the system, and the seals in the lever would fail if you were to use SRAM fluid.

The SRAM rear derailleur (mech) will not work with a Shimano shifter as is; the cable pull and shift activation ratios are not the same between the two systems. Again, I refer you to table 5.2 of Zinn and the Art of Road Bike Maintenance, 5th Edition for a complete listing of rear shifting specifications for all Shimano, SRAM, and Campagnolo road and mountain drivetrains from 7-speed through 11-speed. You could get a JTek Shiftmate 4 and make the cable enter the large groove in the pulley; that should make them compatible.

If you do get a Shimano rear derailleur, you would need the GS (long) cage if you have an 11-32 cassette. If you have an 11-36 (mid-cage SRAM RD) or a 10-42 (long-cage SRAM RD) cassette, you won’t be able to use a Shimano road rear mech.

With a Shimano rear derailleur, you would want to run at least an inner stop and an outer chainring guard, or better yet, a chain guide bridged over the chainring. You will not have the clutch feature of the SRAM X-Horizon rear derailleur, so chain retention would be considerably less dependable with the SRAM X-Sync chainring and no chain guide. I personally would not run a Shimano rear derailleur on a 1X in cyclocross without a chain guide, no matter how tall and fat every other tooth on the chainring is. Even with the SRAM X-Horizon rear derailleur, I would still run a chain guide if you ever race in freezing mud.
― Lennard

Feedback from a February column

Dear Lennard,
The advice you gave Michael about spraying WD-40 into his shifter has saved me (and some friends) a few hundred dollars over the years, as I’ve been able to breathe new life into some old, sticky shifters. I find that, while not always necessary, if I remove the shifter and spray the heck out of it with WD-40 while leaving an old cable in it and shifting it both ways through the complete range with the cable under tension and then carefully lubricating it as you indicated, even the most stubborn worn and erratic old shifter can be brought back to life.

However, it appears you misspoke when you said this: “Yes, you can also use a 6800 lever with your derailleurs, but you’d have to get an 11-speed cassette and a wheel with an 11-speed freehub.”

An 11-speed shifter will not correctly shift a 10-speed rear derailleur even on an 11-speed cassette … the cable pull for 10- and 11-speed rear derailleur are not the same.
— Steve

Dear Steve,
Thanks. You’re indeed correct about the different cable pulls of Shimano 10-speed and 11-speed shifters (and the different shift activation ratios of Shimano 10-speed and 11-speed rear derailleurs). Fortunately, I corrected my error a couple of days after posting, so the version that has been online since February 16 is accurate.
― Lennard

Dear Lennard,
The note from the reader with stiff shifting might also be related to a frayed cable. If the shifters have seen enough service to need cleaning and lubing, there is a fair chance that the shift cable is past due for replacement. If the shift cable is kinked enough to allow even one fiber to come free, it will produce the kind of weird shift behavior the writer describes. I can’t count the number of times I’ve gone looking for a zebra in my drivetrain when the problem was just a plain old horse.
— Jim

Dear Lennard,
Just read the article on the Shimano shifting troubleshooting. Shifting problems can come from poorly maintained cables and housings as well, and are all too frequently overlooked.

I have a Campagnolo 9-speed setup, and for many years I periodically have had similar shifting issues. I’ve learned over the years that at some point I need to just tear into the complete shifting system and clean and replace some parts. At the beginning of a new year I take the shifting and brake cables and housings off and inspect them for dirt, rust, etc. If I have any doubts, they all get replaced.

With the Campagnolo 9-speed I can rebuild the shifters [ed. note: instructions for rebuilding all generations of Campagnolo Ergo Power levers are in Zinn and the Art of Road Bike Maintenance, 5th Edition.]

I also take the front and rear derailleur off. The front gets disassembled, cleaned, lubed, and reassembled. The rear goes into a coffee can full of degreaser and sits for a few days. It then gets removed and blown off using my air compressor. It then gets every moving hinge point lubed and put back on the bike.

Since I had 1,800 miles on the chain I only cleaned the chain and cassette. After I put everything back together, I have about 400 miles in 2017. It shifts just like new.
— Lee

Dear Lennard,
I was told that the reason for the different brake lever sides is due to the side of the road that you ride on, and subsequently the hand you want free for signaling.

The logic goes something along the lines of having the hand nearest the traffic available for signaling, whilst operating the REAR brake with the hand that remains on the bar, thus eliminating the risk of an endo.

So here in Australia, where we ride on the left side of the road, the rear brake is operated by the left hand and the right hand is free to indicate a right turn with an extended arm across the traffic, or a left turn with a bent right arm, still visible to the traffic.
— Stewart

Dear Stewart,
Very good point! Thanks!
― Lennard