Bicycle Mechanics - Shimano 7-speed Cassette Question

I have a 7-speed (11-13-15-18-22-26-34) MegaRange cassette that I'm trying to use on an old Shimano FH-M732 Deore XT hub. The cassette has the 5 larger gears fixed together and the 11 & 13 are loose. However, the 11 has a "shoulder" built into that stops it when it slides onto the hub body. When I install the cassette and tighten down the lockring, it doesn't completely tighten up the cassette. The 13 is still loose. The shoulder on the 11 keeps it from pressing down onto the 13 when the lockring is tightened.

If the 11 were installed by itself on the hub, it wouldn't go any further than it does with the rest of the gears. This cassette was new-in-the-box when I got it. As such, I think all of the parts are there. There is a spacer between the 13 and 15. The 11 with the shoulder is the correct thickness to set the proper spacing between it and the 13.

I can get it to tighten up by putting a spacer behind the entire cassette, but I'm worried that I won't have clearance between the 11 and the chainstay because it pushes the entire cassette that direction. When I do this, there isn't a whole lot of room left between the outer face of the lockring and the drive side axle locknut on the hub.

The hub is one of the older ones that has both internal and external threads. I have a different 7-speed HG hub that fits perfectly and snugs right up.

What gives with the hub that has the shouldered 11 gear? I guess I could replace the 11 on it with a "normal" 11 and it would work fine.

Any input would be appreciated.

http://www.sheldonbrown.com/gloss_ho-z.html#hyperdrivec

Thanks for the link. However, I'm still not clear on why the 11 tooth gear is built with the shoulder in it that prevents it from sliding further onto the hub than it does. For this cassette to work, the hub body that it goes on would have to be a little shorter than the one I have. I believe the one I have is a normal 7-speed hub.

A spacer will push the entire cassette over, but it will push it over by less than the width of the spacer. Once you tighten everything down, the 11T cog will still be very close to bottoming out and very little net change will happen.

Sometimes cassettes are a little loose - or freehub bodies on the hub are a little wide - and you need a spacer. It is not a big deal. Add a spacer and move on.

(BTW, if you add a spacer and for some reason it does not fit inside the stays (damn unlikely IMHO), remove the spacer and check back for more ideas)

Older Shimano freehub bodies were not compatible with 11T small cogs and Shimano later modified the design to Hyperglide C with the "C" standing for compact. These "C" freehub bodies have splines that don't go quite to the end of the body and allow an 11T cog to seat properly.

Older bodies with full length splines won't fully seat an 11T cog. You need either a C-body or use a file to relieve the splines on your older body.

What gives with the hub that has the shouldered 11 gear? I guess I could replace the 11 on it with a "normal" 11 and it would work fine.
The extra material is there to keep the thing from spliting. That's the only 11t made that I know of.