There is somebody in the uk?thats been making hardtail on shaft driven bikes for years.their hardtail goes on the outside of the drive shaft and final drive.plus they have extended the drive shaft.they build the hardtail on the original frame.ive welded a harly bolt on hardtail to a cb750 b4.the ones out of the uk look like they had to have the rear axle lengthened.i was just thinking I might try it myself at income tax time if I can find a junk vn750 and the 800 swing arms are certainly cheap enough.so why not