Background:
I have a set of 2010/2011 Mavic K Sl's, as well as an older set of K Elites. I've been using D/A 7700 9 spd for a while - with good shifting results. SRAM PC1090 Chain. Both hubs have aluminum spacers that I use on the back of the cassette body (I put the spacer on, then the cassette) - and both spacers are different sizes.

I upgraded to SRAM Red, initially using 5700 105 10spd cassette to ride on rollers with. Shifting and riding seemed quite smooth.

Now, I just received my new 2012 Red cassette, and my backup 1070 Rival cassette. Put the Rival cassette on the same wheel I took the 5700 cassette off of, and I had decent vibration when on the rollers today. Its the kind of vibration when it seems like the chain isn't perfectly mating up to the gears.. or like when you have two gears that are to tightly pushed together when they start spinning fast.

I put my other wheel on with the Red cassette - to much the same effect, though it was a bit better. The other wheel has slightly different spacing.

So any ideas? One thing I'm wondering about is the cassette body spacer that goes on each hub (towards the hub end of the cassette body, put on before the cassette goes on). Is there a need for this spacer with 10spd? I also noticed that in the 11t cog, the chain is awfully close to the frame dropout.

I have yet to switch back to the 1070 cassette to just confirm the vibration is gone - but it seems pretty clear cut.

Thanks for the help!

you should need the mavic spacer with either of those cassettes, but i have only seen one thickness. the shimano spacer is much thinner, without the recesses that the mavic spacer has (at least the one i used with my 2009 ksyriums).

i wasn't aware that mavic had two different thicknesses of spacers, but they might.

regardless, it is not unusual to have to adjust the cable tension on the RD when changing cassettes, especially if you are going from SRAM to Shimano, or one design to another within a manufacturer. it sounds like you just need to fine tune the cable tension when you swap the cassettes.

Your chain is worn.

Thanks for the replies. I did make fine-tuning adjustments when I put the new cassettes on - the shifting was way off from Shimano to Sram. But i'm wondering if its a matter of just a bit more dialing in - perhaps due to the smaller spacing on 10spd? Having only ridden and adjusted 9spd, I think this could be a possible issue.

As for the chain being worn - it has 1600 miles on it. I love buying new stuff -but I think this should last quite a bit longer. Now, if your going to say that the chain's wear pattern is based on shimano cassettes, and moving to Sram could create an issue, I may believe that.. any chance this is the case?

1500 miles is my oft-quoted "average" for road bike chain wear, excluding campy. so your chain is worn.
Mavic spacer is aluminum, 1.75mm thick, sometimes referred to as the M10 spacer (because they call their shimano compatible road freehub M10).
There is a smaller, steel 1mm thick spacer that comes with shimano 10speed cassettes that is used with any SHIMANO 10speed cassettes on "conventional" freehub bodies.
The mavic spacer always stays with the mavic wheel. the shimano spacer always stays with the shimano cassette.
so, with a shimano 10speed cassette, it should go mavic spacer, shimano spacer, shimano cassette.
with a sram 10speed cassette, it should go mavic spacer, sram cassette.

Hmm... ok. Thanks for the additional info, especially on the spacers.

I ordered a new KMC X10sl off ebay just now.. Guess it can't hurt weather it's worn or not - new season, new chain.

New Cassette, New Chain = Win
New Cassette, Old Chain = No
Old Cassette, New Chain = Ok
Old Cassette, Old Chain = Ok

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Exp001

If I still worked in a shop, I would make wallet-sized reference cards to hand out with this brilliance upon them.

first what is the mileage on the chain? if you've been riding on an old chain and put a new cassette on they won't match well, you may need to replace the chain, do you have a chain stretch tool to check