Ortlieb QL2.1 pannier hook insert replacement
Ortlieb Back-Roller and Sport-Roller panniers use QL2.1 hooks with small plastic inserts that adapt the hook to rack tubing of 8, 10, 12 or 16 mm; the inserts are the first thing to vanish when you swap racks. This replacement snaps into the hook with the same rear tabs and offers an inner radius matched to your Tubus, Thule or Topeak rack tube, 0.3 mm oversize so it slides on and off cleanly. Walls are 2.5 mm and it prints on its flat back in PETG or nylon at 100 percent infill for durability.
Ortlieb sells inserts, but not always in the size your rack needs, and a downloaded file for 10 mm tube rattles on an 8 mm one. Give SpeakCAD the tube diameter and the hook slot you measure, preview the insert free in the browser, refine the snap tabs in the chat, then download the STL.
Design a pannier hook insert 30 mm long and 14 mm wide with a 12.3 mm radius channel for a 12 mm rack tube, 2.5 mm walls, two 3 x 6 mm snap tabs on the back with 1 mm lips and 0.5 mm chamfers on the leading edges.