Mavic Ksyriums SSC
 

Just purchased a almost new 2003 Mavic Ksyrium SSC wheelset. There was a spacer on freehub when I received wheelset. I assumed this was for 9 speed cassette. When I installed the 9 speed cassette on hub I cannot get it to tighten properly. The cassette has some movement on hub and this is not normal for a proper fit. The spacer is about half the width of a normal 9 speed spacer(the one between the cogs)
Do I have the wrong spacer? Please advise.

You mentioned the wheel came with a spacer, that means it is a m10 wheel (will work with both Shimano and Campy cassttes) The spacer is used for Shimano cassette bodies only (8,9or 10 speed). If you have a Campy cassette, remove the spacer and you are good to go!

Just a side note: If you were sold a E10 wheel (with a spacer thrown in by mistake) it will ONLY work with Campy goodies not the "big S"

I assume it is a M10 wheel, because I installed Shimano 9 speed cassette on hub.
Will a Shimano cassette fit onto a Campy hub?
Can I find the M10 I.D. stamped on hub?

I've had the same problem on the SSC-SL only with a Dura-Ace 9-Speed cassette using the original Dura-Ace lockring. It seemed pretty "thin" and I could not achieve a good "crush" on the cassette's cluster. I used a TIOGA brand aluminum lockring I scored on Ebay and it worked much better. You could also add a(nother) thin round shim to make up the difference...

I've taken a spacer ring from my spare cassette and can now get the cassette tight on the hub. I can't believe no one else has not had this problem. It is a standard setup Mavic SSC Sl with a Durace cassette.