[SBH1973]

I recently swapped my SRAM Red 11-28 Cassette for an Ultegra 12-27 (much quieter with a DA chain). I noticed that the inside ring - a thin hollow cylindrical metal piece – of the SRAM cassette, which I'd like to sell, is lose. This is not the case for an 11-23 I have as well. Does this matter? Is it defective or broken? Can this piece be retightened? I'm wondering if this was the primary source of my noise.

On another note, I decided to install this cassette on a DTSwiss DT-240 shimano hub I have on another wheelset. It does not fit, but got terribly stuck. When I put some muscle into pulling it off, the entire free hub assembly came apart. Still had to tap the free hub off of the cassette gently using a hammer and flat head screwdriver. What a mess! Do these things go back together??

 

[FBinNY]

Not sure what the loose ring is, but it's probably a spacer needed to properly locate the back sprocket, and which would be compressed when the lock ring was tightened. It wasn't the cause of your noise, which is a combination of Sram's sprocket gates (cut down or thinned teeth) and the once piece cassette resonating like a bell.

Probably the reason the Sram cassette jammed on your used freehub body is because the prior cassette cut into the body and raised some burrs, or peened the edges over a bit. The long one piece spline is less forgiving than individual sprockets might be because it's hitting all the burrs rather than only one or two, so you can't work it past as easily. If you've got the cassette off, use a small file to clean up the raised edges on your freehub before re-installing it and you'll be good to go.

The bright side is that Sram's one piece design spreads the load and doesn't beat up freehub body's the way that individual cog cassettes do.

 

[SBH1973]

Thanks FB. The loose metal ring/cylinder is sandwiched between the 3rd and 10th gear of the cassette. (see picture) It is loose enough to turn around, but not fall out.

 

[skaruda_23]

The thin cylindrical sleeve on the inside of the cassette is meant to be slightly loose like you describe. There is nothing wrong; it can't be tightened at all. The noise is an inherent outcome of the design just like FBinNY described.