Originally Posted by
Eggman84
Please explain how I am wrong and I have no idea what you mean by "the manufacturer wants to lose business by insisting on only using those two cassettes"? What manufacturer and what cassettes?
But to give you credit, I believe you are correct. I don't run 11 speed but if I remember correctly, the largest 11 speed MTB cog "overhangs" the end of the freehub body. So the freehub body only has room for 10 cogs, with the 11th cog attached to the 10th and overhanging. Please correct me if I am wrong. Point me to a tech document to set me right (may help the OP also).
I've been watching some mtb cassette installations, mainly onto road bikes, and I don't think the 11 cog overhangs the freehub with any mtb cassettes. From what I understand, the 11 speed cassette is the same width as the 10 speed cassettes and they accomplish that by making the 11 speed cogs thinner. Maybe I've interpreted something wrong but that's what I think's happening.
With the SRAM XD Driver that you need for a 10 tooth cog, the 10 tooth cog is still not overhanging, but it is floating around the end of the hub which has narrowed towards the end. For that reason, it also accepts a 9 tooth cog. The first couple of big cogs are placed on a spline of normal dimensions, but that's it, the rest of the hub gets narrower and is different. The lockring goes right through the first several smallest cogs and stops at that bit where the spline is of short but otherwise normal dimensions. It's quite a technical marvel!