SRAM PG950 Cassette Play On Mavic Aksium Wheel

[Cletus Van Damme]

I wanted to lower the gearing on my bike and got an SRAM PG950 9 speed cassette. I have fitted this to my Mavic Aksium 2011 rear wheel using the spacer that came with the wheels and there is still a very small amount of play. The lock ring is tight. I am just a bit confused as I read on here that the spacer is not required for 9 speed cassettes, but I had to use it with the Tiagra cassette that this has replaced and it worked perfectly. The SRAM website is a joke, I am guessing that I maybe need a bigger spacer but it will have to be not much bigger by my reckoning. Not sure where to get one from either. Has anybody any advice please?

 

[Radchenister]

I had a Shimano spacer that was all firm when first put on new wheels last week but the cassette had worked very slightly loose after the first long ride earlier this week - the end cap was still on tight so the spacer was obviously too thin - I went for the one below.

My cassette is a PG850 on my Mavics - don't know if the width of the cassette is greater for yours or not (?) - the part from below does say for conversion of 10 to 8/9, although their description is muddling the body and cassette sizes back to front - I fitted it as a replacement to the Shimano one last night, it's slightly thicker and it appears that all's now well.

http://www.chainreactioncycles.com/Models.aspx?ModelID=25399

 

[Radchenister]

http://www.wiggle.co.uk/shimano-cs-hg-1mm-sprocket-spacer/

Further to last, this is the style of spacer it replaced - to be factual, I believe the one replaced was a Shimano one (castellated profile type) but it was a loose item acquired as a quick fix from the LBS with no packaging, so I couldn't be absolutely certain, although it looks identical.

 

[Cletus Van Damme]

I had a Shimano spacer that was all firm when first put on new wheels last week but the cassette had worked very slightly loose after the first long ride earlier this week - the end cap was still on tight so the spacer was obviously too thin - I went for the one below.

My cassette is a PG850 on my Mavics - don't know if the width of the cassette is greater for yours or not (?) - the part from below does say for conversion of 10 to 8/9, although their description is muddling the body and cassette sizes back to front - I fitted it as a replacement to the Shimano one last night, it's slightly thicker and it appears that all's now well.

http://www.chainreactioncycles.com/Models.aspx?ModelID=25399

I think your cassette is 8 speed mate whereas mine is 9. That looks identical to the spacer that I am already using that came with the Mavic wheels, but it is not quite enough and there is still play. I may try the one that you have listed in the second reply along with the Mavic one. I am not quite sure if it has much as 1mm play in it, but it is certainly effecting the shifting from the largest rear sprocket down to the one below. Just a bit of a pain as I thought SRAM cassettes were directly interchangeable with Shimano ones, but this one is certainly slightly narrower. Thanks for the links much appreciated.

 

[Radchenister]

It is 8 speed, surprised the 9 is thinner but thinking about it, it's possible they're packed in more tightly.

The castellated one is pretty thin / flat, verging on flimsy, it's sat next to me on my desk, it can easily be bent out of shape as it's made from quite a pliable metal - in fact, I just bent it a bit and had to flatten it out again.

One point to consider is that there's no indents in the horizontal plane (from the perspective of viewing it flat on a desktop), unlike the other one - thinking aloud, I'm not sure how this would effect compatibility with having two side by side, as set on the hub, between the cassette and hub inner edge - didn't take the time to suss what the indents fitted as the spacer appeared only to fit one way around, so just refitted it quickly.

They both fitted fine on the hub individually, the thin castellated one was just a tad under width for what was needed in my arrangement.

Together they should / might work OK, just need to be wary of those indents on the side of the non-castellated one - I can't remember now which side the indents went when fitted but I'm sure you will be able to work it out with them both in front of you.

Hope that makes some form of sense as quite difficult to explain using text?

Edit: not sure on the indent position either now, just checked the bike and the recesses are on the cassette side, this might be an error but then again it might be designed to fit either way and it may be OK, as if the other way round, it might means less spacing again?

One to keep an eye on!

 

[Radchenister]

I also found this elsewhere on the net:

8 speed is the same width as 9 speed. 10 speed is like 1mm narrower than 8/9 speed.
----------------------
8/9 requires the standard Mavic Spacer.
10 requires the Mavic Spacer + the Shimano spacer (1mm-ish)
------------------------------------
NO spacer is required for Mavic's M-10 cassette which is campy spaced....but nobody really uses those.

http://forums.roadbikereview.com/wheels-tires/mavic-wheel-cassette-installation-issue-124509.html

 

[Cletus Van Damme]

Thanks very much for your help mate it's much appreciated. I am going to have to try the Shimano 1mm one that you have listed. I think 0.5 mm would do but such a thing does not seem to exist.

 

[Radchenister]

Just a quick update, the new spacer I fitted was used for the first time yesterday (an hour and a half(ish) ride); the recesses in the shim appear to be drain holes that fit against the cassette side.

All still rigid after the ride, so sorted in my case - for clarity, my set up is: Mavic Aksium 2013 Wheels - SRAM PG850 Cassette - standard spacer from Chain Reaction Cycles (as link above).

I've posted this in case others read the thread, as the info' you have to trawl through over the net never seems to give a definitive answer.

PS - I am also assuming the PG950 must have a slightly different dimension to the PG850 - although this would need to be confirmed.