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  1. #1
    Wax
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    Sram 950, 970, 980, 990?????

    so I'm going to replace the drivetrain on my Iron Horse MK III. I'm switching out the rings, chain, and cassette as they're all shot. the question is about SRAM's numbering system, and what's the difference? I realize that the higher the number the higher the bling factor and also the higher the price. I know the weight drops a bit as you go up, but not too much. I'm looking for good quality parts that will last through really hard riding in Maine mud.

    I'm thiking the middle of the road stuff (950) is probably fine, but I don't have enough experience with the others to know if its worth spending some extra money.

    thanks for the help!
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  2. #2
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    The main difference is weight. The 950 casette being the lowest end will be considerably heavier than the 990, which has a completely different design.

    If you dont care too much about weight, then the 950 will do you fine. In terms of durability, ive found there is negliglible difference between high end and low end cassettes, with the exception of shimano's XTR cassette which uses fast wearing Ti cogs. Although, i have found that shimano cassettes last longer than their SRAM equivalent.

  3. #3
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    Quote Originally Posted by superlightracer
    The main difference is weight. The 950 casette being the lowest end will be considerably heavier than the 990, which has a completely different design.

    If you dont care too much about weight, then the 950 will do you fine. In terms of durability, ive found there is negliglible difference between high end and low end cassettes, with the exception of shimano's XTR cassette which uses fast wearing Ti cogs. Although, i have found that shimano cassettes last longer than their SRAM equivalent.
    NO, there is a big difference. If your free hub is made of alloy then a you'll need a higher end cassette b/c the lower ones do not have a spider and will therefore put little divets on your freehub, which is BAAAAAD. Chris Kings are really soft BTW.

  4. #4
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    Quote Originally Posted by Jwind
    NO, there is a big difference. If your free hub is made of alloy then a you'll need a higher end cassette b/c the lower ones do not have a spider and will therefore put little divets on your freehub, which is BAAAAAD. Chris Kings are really soft BTW.

    Please explain.

  5. #5
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    Just like I said, Higher end cassette's sit on a spider, thus distributing force to all areas on the freehub splines. Lower end cassettes are merley riveted together, thus each cog exerts almost all of it's force on the freehub in one area. If the Freehub is soft aluminum, it will divet. It's a common problem, and it's also why SS'ers use wide based SS cogs.

    This is what the 990 spider looks like. I can't find a shot of a NON spider cassette.


  6. #6
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    Quote Originally Posted by superlightracer
    The main difference is weight. The 950 casette being the lowest end will be considerably heavier than the 990, which has a completely different design.
    Wrong, the PG950 cassette according to the sram website is 230g, the PG990 on the other hand is 290g. The 990 sure does look good, if only the lock ring, and spider were gold..
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  7. #7
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    Quote Originally Posted by Quiksilver
    Wrong, the PG950 cassette according to the sram website is 230g, the PG990 on the other hand is 290g. The 990 sure does look good, if only the lock ring, and spider were gold..

    That's probably attributed to the non-spider construction.

  8. #8
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    Quote Originally Posted by Quiksilver
    Wrong, the PG950 cassette according to the sram website is 230g, the PG990 on the other hand is 290g. The 990 sure does look good, if only the lock ring, and spider were gold..
    Hey, the 11-26 PG-950 is 230g claimed. The smallest 990 is an 11-32, which comes in at 275g claimed.

    Comparing an 11-26 to an 11-32 is just not fair. For the same gear range, the 990 is significantly lighter.

    So, if you don't have a mushy king freehub body, an you are not concerned about weight, there is no reason to spend a lot of money on a cassette IMO.

    Personally, i think the red spider looks really cool though.
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  9. #9
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    FWIW, a soft freehub body is not exclusive to CK... I9, hadley, hope and even my Ringle hubs, have the same issues.

    THere is a Stainless steel freehub available from CK though.

  10. #10
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    Quote Originally Posted by Jwind
    FWIW, a soft freehub body is not exclusive to CK... I9, hadley, hope and even my Ringle hubs, have the same issues.

    THere is a Stainless steel freehub available from CK though.
    true that
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  11. #11
    rad to the power of sick
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    Quote Originally Posted by Quiksilver
    Wrong, the PG950 cassette according to the sram website is 230g, the PG990 on the other hand is 290g. The 990 sure does look good, if only the lock ring, and spider were gold..

    Like rkj said, compare apples to apples.

    The 11-34 950 is close to 430g from what i remember.

  12. #12
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    Quote Originally Posted by superlightracer
    ..... with the exception of shimano's XTR cassette which uses fast wearing Ti cogs.
    Sorry to hijack this thread, but can you explain about "fast wearing Ti cogs"? I would have thought that Ti would be slow wearing due to its hardness. I've been seeing some new & used XTR cassettes on eBay & was thinking of bidding. If I can't expect them to last as long, maybe I won't. Thanks.
    Whatever your hand finds to do, do it with all your might.... (Ecclesiastes 9:10)

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