Headset bearing press drift set for 1 1/8 inch steerer
A pair of stepped drifts that turn an M8 threaded rod, two nuts and washers into a headset bearing press for integrated and zero-stack headsets. One drift steps 41.0 and 41.8 mm for IS41 and ZS44 bearings, the other 51.8 and 52 mm for IS52 and ZS56 lower bearings on tapered forks, each with a 9 mm centre bore and a 3 mm flange so the press acts on the bearing race, never the seal. Print them flat in PETG at 100 percent infill; the loads are low and mostly in compression.
Bearing outer diameters vary between Cane Creek, FSA and Acros, and a downloaded set may be a fraction big and mar the head tube. Tell SpeakCAD the bearing diameters and steerer size you have, preview the drifts free in the browser, add a crown race step in the chat, then download the STL.
Design two stepped headset press drifts each 20 mm tall with a 9 mm centre bore: one with 41.0 mm and 41.8 mm steps 6 mm tall, the other with 51.8 mm and 52.0 mm steps, both on a 60 mm diameter, 3 mm thick flange with 0.5 mm chamfers.