Sasquatch16

I have a Mavic Kysrium Elite S wheel with an Ultegra 6700 12-30 cassette. I removed it to install a Sram 12-32. The Ultegra cassette had 2 shims, one thick and one thin that went on hub first. Leaving these on when I installed the Sram cassette there was not enough room to put the last cog on so I removed the thinner of the 2 shims and the small cog went on. Should this last cog be flush with hub, protrude slightly? What is the correct way to shim this? thanks

HillRider

Does the locknut tighten firmly against the smallest cog with no wiggle or movement in the cassette body? If so, you are good. However, those 1 mm shims are provided with all 10-speed Shimano cassettes for use on their 8/9/10-speed freehub bodies while SRAM cassettes do not need it. Mavic requires the additional 2 mm shim on their freehub bodies so I expect using the 2 mm but deleting the 1 mm is the proper arrangement for your SRAM cassette.

Sasquatch16

Okay thanks. Nut tightened down fine. Not sure if I will notice the extra 2 cogs or not but figured it was worth trying. I live in a hilly area and am not a light weight. That being said the Shimano Ultegra cassette looks to be much better quality than the SRAM PG1070. Shifts okay in stand but if I do not notice a difference tomorrow riding I will end up changing back.

Bill Kapaun

I think I would experiment trying to use minimal thickness of shims that allows maximum engagement of the lock ring without loose cogs.

IF a 30T cog just barely gets you up the hill, 32T will be noticeable. It may be a situation where an inch seems like a foot.

Al1943

It's my understanding that with a SRAM cassette you do not need the 1 mm Shimano spacer. I'm assuming that the thicker spacer is for a Mavic hub and would have come with the hub. So you would need it.

FBinNY 

There's no need to remember every possible cassette/freehub combination if you understand one basic principle. The system is analogous to how threadless headsets work, in that the cassette has to overhang the freehub so that the lockring bears on the cassette without bottoming against the freehub body.

It's that simple, add/remove spacers behind the cassette to bring the front out to slightly over 1mm overhang, install lockring and go. On the off chance that the cassette compresses more than you allowed, add another spacer and repeat. If you're unsure whether the lockring is compressing the cassette put a tire lever between any two sprockets (not any that share a spider, if any) and pry gently and see if you can push sprockets apart.

For those who use multiple wheels on the same bike, you might use micro-spacers behind the cassettes they all come to the same distance from the locknut face. That will allow wheel changing without needing to adjust RD trim.

Sasquatch16

As FB mentioned I just looked at last sprocket I installed to make sure it just protruded a little bit so everything would tighten up. Ended up leaving off 1mm spacer which goes with the Shimano cassette and left on the 2mm which goes with the Mavic wheel. Thanks you all for your help.

OldsCOOL

Well said!