I have a NOS Supercross to build for my new season, but I'm having trouble sorting the headset.
I bought a Cane Creek 45/36 but that just falls through.
Measurements seem to put it in the middle of industry standards. Measured with an old tape 48mm OD and about 42mm ID.
My next guess is a FSA Orbit Z for 50mm OD and 44mm ID frames.
There are no angular faces, just a straight 90o lip about 10mm inside both top and bottom.
My thinking is it can't be anything 'unusual' as the frames about 2006/2008. And all the Supercross's I can see online have FSA's fitted.
Of course if anyone has one of these, be a love and have a peep.
I have two Crossbows from that same period. They both have a steel bearing race that sits in the headtube. Then the smaller of the two integrated headset bearings sit in there. Perhaps that's the same for yours? Good luck tracking down an answer, no one seems to know anything about mine.
The inside diameter measures between the industry standards. IIRC 44 ID and 42ID? I forget the details beyond that.
That FSA Orbit Z has cups that press in first and have a small flange that sits on the rim of the headtube, does that sound familiar?
Frame....internal bearing cups.....then bearings.
On mine the races are proprietary. I'd get some calipers on your headtube instead of guessing around. I tried the FSA headset with the cable hanger and it didn't work because of the non standard ID.