I just installed a new SRAM OG-1070 cassette on my wheel.
I had to use the original spacer I had from my old Shimano cassette.
Without it the cassette wobbles.

Anyone care to comment? I know some hubs require spacers to get the chain line more centered on the crank.

10-speed cassettes are slightly narrower than 9-speed cassettes. On an 8/9/10-speed compatible hub, they need the spacer behind them so the lockring can tighten to specs against the smallest cog.

/w

10-speed cassettes are slightly narrower than 9-speed cassettes. On an 8/9/10-speed compatible hub, they need the spacer behind them so the lockring can tighten to specs against the smallest cog.

/w

Sram cassettes are not supposed to be 1mm narrower, since they can never be installed on a Shimano "10 speed only" hub with aluminum splines. They are supposed to be the same width as Shimano 9 cassettes.

Mavic hubs, with the M10 spline, have a 2mm thick spacer that must be used with all cassettes. The only time it's not used is if Mavic loose cogs are installed with Campy spacers.

Sram cassettes are not supposed to be 1mm narrower, since they can never be installed on a Shimano "10 speed only" hub with aluminum splines.

Absolutely correct. My brain was locked on Shimano. Anybody know why the SRAM OG-1070 wants a 1 mm spacer behind it?

I believe the difference is not the entire width of the cassette, but the depth of the "splines". Shimano 10spd is much deeper such that 9spd or SRAM cassettes will not fit. The Shimano 10spd cogs tend to cut into cassette bodies because of this additional depth to fit the taller splines of the Shimano 10spd cassette bodies.

still the sram 10 sp cassette should not require a spacer, niether of mine do, however that spacer is very thin and if it means the cassette does not wobble then run it, however i would make sure nothing is missing from your sram cassette first or see if other cassettes fit onto your freehub without the spacer. Try a 9sp mountain cassette, if it wobbles then something is up with the freehub body, if it's solid without a spacer then something is up with your 10 sp sram cassette.

Strange, on my spare set of wheels (Odds and Endos, by Mike Garcia), they don't require the spacer.

Shimano and SRAM cassette on Mavic wheel need spacer
Shimano and SRAM cassette on Custom wheel, no spacer.

I guess it can be specific to who makes the hub.

Strange, on my spare set of wheels (Odds and Endos, by Mike Garcia), they don't require the spacer.

Shimano and SRAM cassette on Mavic wheel need spacer
Shimano and SRAM cassette on Custom wheel, no spacer.

I guess it can be specific to who makes the hub.

Are you saying that you are using both the 2mm spacer supplied by Mavic and a 1mm Shimano spacer? The 2mm spacer is always required for a Shimano 9 or SRAM cassette.

Just the 2mm spacer supplied by Mavic
On the Speedcific hubs, i don't need any spacer

Just the 2mm spacer supplied by Mavic
On the Speedcific hubs, i don't need any spacer

I explained in my first post that the Mavic M10 hub has longer splines, with the Shimano pattern, to accept Mavic loose cogs with Campy spacing. The use of the 2mm shim is normal for Mavic hubs.

Anyone have a link to a site where you can buy the 2mm mavic spacer?
thanks