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(aka SS_MB-7)
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I've got 2 SRAM cassettes: 990 11-32 and 970 11-34. The 990 was replaced with the 970 after a very hard season of racing (TransRockies), etc. in ~Oct. Since then, riding has been minimal due to a harsh Winter (snowshoed instead). While overhauling my King rear hub yesterday, I removed my 970 cassette and was shocked to find that:
1 - the cassettes cogs had gouched the King's cassette splines; and,
2 - I could physically twist the cassette several degrees.

By grabbing the 34T with my left hand and the 14T with my right, I can physically twist the cassette by turning clockwise with my left hand and ccw with my right. This can't be good! Warranty?

In the 970 cassette, the 7 main cogs are individual (with spacers) and are pinned together with 3 pins. Over time, it appears that these pins have developed some play and are no longer keeping the cassette togther. Grrr! The 990 cassette is a single cassette body...not individual. No more 970s for me!
 

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Yeah the CK's aluminium freewheel shell doesn't get along very well with individual cogs. Its too soft and really requires a cassette with a solid cog carrier taking up as many rings as possible. They make a stainless steel shell for that reason but it weighs 45g more.
 

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nobody
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1speed_Mike said:
By grabbing the 34T with my left hand and the 14T with my right, I can physically twist the cassette by turning clockwise with my left hand and ccw with my right. This can't be good! Warranty?
That's interesting. That might just be how they're made. I recently bought a Sram 850 8sp cassette and noticed it did this right out of the box. It was just a replacement for an old 8sp rig I have and was cheap ($20) so I just installed it and haven't had any problems with it "flexing" while under load. Of course it's on a shimano freehub with a steel cassette body which probably helps.

I thought the 850 was just made like this because it was cheap. I didn't think it extended into their higher end stuff. I was thinking of getting a 970 for my main ride this year but after hearing this I'll probably spend the extra $$ to get the 990.
 

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There is a replacement for the 990 that is coming out I think.

It has a red spider that holds all the cogs together. Pretty sweet looking.

Details below taken from the homepage link to SRAM's show and tell...



SRAM's new PG-990 Rear Cassette is machined from 1 piece bar stock aluminum so it is extremely stiff, which gives the rider tighter and more precise shifting. I witnessed this first hand as I've been running SRAM X.0/X.9 drivetrain for the last two years. The engineers kept reiterating that the cassette is the reason that the new product shifts so well. It is light weight and looks really trick.
 

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nobody
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frankenbike said:
There is a replacement for the 990 that is coming out I think.

It has a red spider that holds all the cogs together. Pretty sweet looking.

Details below taken from the homepage link to SRAM's show and tell...



SRAM's new PG-990 Rear Cassette is machined from 1 piece bar stock aluminum so it is extremely stiff, which gives the rider tighter and more precise shifting. I witnessed this first hand as I've been running SRAM X.0/X.9 drivetrain for the last two years. The engineers kept reiterating that the cassette is the reason that the new product shifts so well. It is light weight and looks really trick.
That's hot! Aside from looks, it makes sense that if the cassette cogs are flexing you could have sloppy shifting especially under loads.
 

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frankenbike said:
There is a replacement for the 990 that is coming out I think.

It has a red spider that holds all the cogs together. Pretty sweet looking.

Details below taken from the homepage link to SRAM's show and tell...



SRAM's new PG-990 Rear Cassette is machined from 1 piece bar stock aluminum so it is extremely stiff, which gives the rider tighter and more precise shifting. I witnessed this first hand as I've been running SRAM X.0/X.9 drivetrain for the last two years. The engineers kept reiterating that the cassette is the reason that the new product shifts so well. It is light weight and looks really trick.
Man that looks hot :D Might be why the SRAM cassettes are seeming to be lowered in price to get them out of stock to get ready for these.

I'll check my PG950 cassette next time I take it off for this play and setup.
 

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I bailed on the -34 970 also, had a bad shift and the sram link somehow got caught on #2 and bent it BAD, made granny unuseable for the rest of the ride. Went back to steel cassettes, no sram for me until until the spidered version is out.
 

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Brown_Teeth said:
I bailed on the -34 970 also, had a bad shift and the sram link somehow got caught on #2 and bent it BAD, made granny unuseable for the rest of the ride. Went back to steel cassettes, no sram for me until until the spidered version is out.
The Sram 950 is chrome plated steel. (Heavier than a box of rocks)
 

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GaryS said:
The Sram 950 is chrome plated steel. (Heavier than a box of rocks)
Didn't know that, thanks for the heads up - maybe that's why my PG950 is still kicking after 900 hard miles in some nasty conditions. As for weight I really don't mind it for right now and truly it didn't feel too heavy to me when I removed it last time, but my friend with the tools said it was - Now I know where to shed some weight when it does wear out.
 
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