Built up a new bike with my old components. On my original rear wheel I had a dork disk along with a thin metal spacer between it and the cassette. I trashed the dork disk but put the spacer in before my cassette. Did a very short 2.3 mile tune-up ride. Did a 17 mile tune-up ride. Weird shifting, maybe some extra noise going over cracks/bumps (chalked it up to going from a full carbon to 1/2 carbon 1/2 aluminum frame).

Checked my cassette and it was loose! Skewer was tight, lockring was pretty tight based on how hard I had to pull to get it off again. Took everything off, cleaned it out real good including the "10s" spacers. Put it all back on. Got it good-n-tight with my Park Tool stuff. Now there's no play.

Did I just not tighten the lockring down enough or is it possibly coming loose while I'm riding?? Do I need to put threadlocker in the lockring threads?

It's possible the cassette was not seated properly. It may have felt like you tightened it enough, but there may have been some small space between the sprockets or the spacers.

Ride it again and see what happens. I would be pretty surprised of the lock ring was actually coming loose while riding.

What kind of wheel are you using? Some of them (Mavic being one example) require a spacer ring in order to have the cassette sit snugly when tightened.

OP - I'd bet that some of the cogs or spacers weren't properly nested, and shifted on your ride.

It still has play even after making sure I tightened it down. The lock ring is definately tight. The rim is a 2006 Mavic Ksyrium SL SCC. The freehub looks great. No gouges or anything. It or the axle or bearings arent loose at all from what I can tell. I'm thinking songfta is on to something... I'm thinking the dork disk was acting as a spacer on my Korso/Titan/Neuvation. I'm sure I didn't leave out anything when I reassembled. In fact when I put on the cassette for the 1st time I moved everything over as a unit. The 2nd time I looked at each sprocket and spacer to make sure they were o.k. and I cleaned the crap out of them because I thought there was dirt or metal preventing tightening.

Where can I get the appropriate spacer for the Mavic wheels?

I moved my Korso's over to my gf's Trek 1000 8 speed and that cassette has no problem. Her Alex Rims AT 450's dork disc is attached to the spokes rather being wedged between the freehub and the cassette like my Ksyrium setup is.

Cassette spacers are needed for some wheel-cassette combos. Ebay or some of your better bike shops might have a couple. I needed one a couple of years ago and the guy at a small local shop swore there was no such thing.

with mavic freehubs there should be a thick 1.8~2mm spacer then the 10sp spacer then the cogs

I believe heirin lies your answer.

IIRC, most Mavic wheels need a spacer, even with a 9 speed cassette. Then if you use a9/10 speed wheel with a 10 speed cassette, you need another spacer for the 10speed cassette.

I stand to be corrected, but that is my recollection of how Mavic 9 speed wheels work with 10 speed cassettes.

IIRC Mavic has a different spacer for Shimy 10's. Stop into any shop that has Mavic wheels on display and they will most likely have one for you to procure.

EDIT: HAHA - 3 of us post at the same time....I lose.

you can use the mavic 9sp spacer from mavic to use with a 10sp cassette. I tried it without the shimano 10sp spacer and just the mavic 9sp spacer, but there was noticeable play.

1.85mm spacer according to my calipers.

Thus you still owe us a tip of the day.

Thx, all. Apparently this is a relatively common problem after doing a search on teh internets

Looking at your picture the thin ring between the spacer and cassette looks like the one between my original dork disk and cassette when it was on my Korso's. Why are you using both instead of 1 thicker spacer?

Clean your cassette

True...figured no one was reading that anymore. Guess I'll come up with one....

The thick one is the mavic spacer, the thin one is the shimano spacer, have to use both since the 10sp cassette is thinner than the 9sp cassette.

the cassette is clean, it's brand new. Keeping a black hub clean is a futile attempt at best.

I got a Mavic branded 1.75 mm spacer and put it on. Turns out that the freehub itself has a smidgeon of play. Not sure if it's normal or not.

Turns out with the spacer there I figured out that the freehub is also worn! This is what I've got going on.

https://roguemechanic.typepad.com/rog...es_a_mavi.html

I'm guessing everyone's Mavic freehubs are worn. You just don't know it yet. $60 and a few allen wrenches and you're home free.

https://www.youtube.com/watch?v=FzoBeJ5HaOI

ah, well at least you found the root cause of the problem.

Yup. Now the question is do I ride around on it until it wears enough to altery shifting or get a new freehub body now.