Here it is … my prototype MC3.1 Airheadset conversion kit complete with 1 1/8″ Chris King bearings. I’m going to play with the dimensions a bit to lower stack height just a tad more (make it more flush with the frame) and I’m also going to change the bearing seat press fit by 0.002″ as they were a little tight, but overall I’m pretty pleased. This brings the front end of the bike down about 1/2″ from my previous setup where I just put reducer spacers in the frame and pressed a regular NoThreadSet into that.
Check out the pictures below. Click on a thumbnail to see a larger version.
Airhead Chris King bearing conversion cups

Bare Cups

Bare Cups

Bottom Cup with Bearing

Lower Race Fit

Inside of bottom cup

RC660 Quick Metal to bond the cup in place

More RC660 on the cup itself

Bonded in place

Top Cup fitup (going to adjust the specs here to reduce the gap between the headset cap and frame)

Installed on the ’99 Pro frame
I can do a run of these if there is interest. I would need an order of 10 to make it worth my time. As for the cost, I’ll talk to my machinist about the price per pair of cups vs quantity produced … plus either a user supplied Chris King headset for the bearings, or an additional cost for me to buy a headset to pluck the bearings out of. I can make these to fit Cane Creek IS bearings as an option too, but the only IS bearings worth a crap are the 110 bearings. I’m only going to make one version of the cups, so if there’s a lot of people wanting CK bearings I’ll do that, if a lot of people want IS bearings I’ll do that instead.
-David