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Old 04-10-13, 01:16 PM   #1
brbarcla
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SRAM cassette question

Greetings, I recently purchased a SRAM PG950 cassette for my shimano hub. The first 7 cogs are attached in a stack and the final two are free. They all fit on the hub (uniquely) however the second to last cog has a strange profile on the inner ring that allows for a significant amount of play on the freehub. When torqued down, everything feels solid but the profile seems very strange to me. Can anyone explain this?

Thanks

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Old 04-10-13, 01:30 PM   #2
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If you are referring to the saw-tooth shape of the indexing spline tabs, it is of no concern. The teeth are square at the lead edge, that is all that matters.
Evidently it is due to some engineering solution to a manufacturing problem that is not apparent to us peons, probably due to the displacement of the metal in stamping the integral spacer into the shape of the cog.
As long as you are applying torque in a forward direction, there is no problem.
However, I would not recommend using this cog in fixie applications. Then it WOULD matter!
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Old 04-10-13, 06:13 PM   #3
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Relieving the backs of the splines speeds assembly by making it easier to slide on without orienting as precisely. Once on riding torque pulls the sprocket forward so the splines are in contact.

This marginal benefit is useless to end users assembling one cassette onto one hub. But imagine working on a bicycle production line assembling hundreds or thousands of these daily, and that one or two seconds saved can add up.
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Old 04-11-13, 11:06 AM   #4
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If the narrow slot on the cog (at ~5:00 in the photo) is on the narrow spline of the freehub, there should be very little play in rotation.

Also, just to be sure, the side facing you in the photo of the smallest cog (on the right in your photo) goes toward the hub. When the locking ring is tightened all cogs should be clamped tight with no play or freedom to wiggle.
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