Headset spacer set for 1 1/8 inch 28.6 mm steerer
Stack-height spacers for a 1 1/8 inch fork steerer, 28.6 mm nominal, in 2.5, 5, 10 and 15 mm thicknesses so you can dial in bar height on a Canyon, Trek or Specialized without buying a bag of aluminium ones. Bore is 28.9 mm for a free slide, outer diameter is 34 mm to match most stems, and edges carry a 0.5 mm chamfer so they seat squarely. Print them flat in PETG or ASA with 4 walls and 100 percent infill; the preload is a light clamp so the material sees only compression.
Spacers for 1.25 inch (31.8 mm) or 1.5 inch (38.1 mm) steerers, or slim 32 mm outer diameters for aero stems, are rarely in a downloaded set. Type your steerer size, stem diameter and the stack you need into SpeakCAD, preview the set free in the browser, adjust it in the chat, then download the STL.
Model a set of four headset spacers with a 28.9 mm bore and 34 mm outer diameter in 2.5 mm, 5 mm, 10 mm and 15 mm heights, each with 0.5 mm chamfers on both faces and a 1 mm wide engraved height label on the outer surface.