Gunnar has expanded the Hyper line from the -X to the -XX and -XC. I am looking at the -XX for a couple reasons. Has S-bend chainstays that the caption says "
increase tire clearance (to 55mm between the stays) as well as heel clearance", and the interchangeable rear frame ends for Q/R or thru-axle (though proprietary bits are also a bit of a potential downside). I'd likely do a custom fork, reducing axle-crown from design-spec of 395mm to 385, to lower the bb from 70mm drop to 74-ish drop, steepen head angle a tad (from 72.5 on the 54cm, haven't done the trig yet), and 65-ish rake for low trail. Also thinking three wheelsets - 559-51, 684-42 and 622-28 for flexibility.
Hyper-XX
Tom