Help finding correct headset for Focus Izalco Max Disc I have acquired a Focus Izalco Max Disc frame and forks and am having trouble finding a headset for it. The steerer bung in the fork reads 28.6mm and it looks to have a slight taper. I have read online that it's a 1 1/8 -> 1 1/4 inch but the headset I have purchased doesn't fit (FSA no53).

The headtube of the frame measures ~42.5mm diameter at the top and ~47mm diameter at the bottom.

I tried the Cane Creek headset finder but it doesn't have my frame model in its database and can't identify any headset models that fit the dimensions I enter.

I have a feeling an FSA Orbit C-33 might be a fit but I can't find any material online to back this up aside from the fact it's one of the few tapered headsets with a 1-1/4" lower bearing.

Any ideas?
This listing has it down as an Orbit C33 SL ACB.

I can't read German beyond getting the gist, but that looks to confirm your suspicions.

I believe the SL and ACB are just the materials / tier of product and C33 is size.