isn’t there some kind of bodge, along the lines of putting a 1.5 headset into a semi-int 1&1/8th headtube ?
found it:
http://www.shedfire.com/2010/09/01/ragley-2011-44mm-headtubes/
Earlier in the year, Cane Creek announced a new headset that allowed people to fit tapered steerer forks to bikes that had 1.125in internal headsets. We liked that, and infact, we’d been paying attention since it was first discussed back in January on the mtbr frame forum. We have since played about with a true “integrated” steel headtube, with bearing races part of the frame, but productionwise it was a nightmare. And so, in conjunction with Nukeproof (well, we design for them too) we stepped proudly to a new kind of standard, with our own headset range to cater for everyone. Thankfully, with Cane Creek on board with this standard too, there is some choice, and even Chris King is joining the party apparently.