When something smooth and round (like a chrome polished tube/pipe/rod) is subject to be hit by something hard, making scratches - You can protect the surfaces by attaching such bumper. Basic version (as seen) has internal diameter (to match the tube/rod) of 20mm, is 20mm wide, and has holes for hexagonal M4 nut and flat-head M4 screw, to keep it strong in place.

The hole for a round screw head has non-round top surface, but a 30deg angled sides - to avoid necessity of supports or bridging (if the speed and layer height is apropriate and material does not shrink too much - otherwise supports may be needed).

Other file formats (incl. 3mf) avaliable on request.

Once my colleague had an MZ Bagira motorcycle, where tubes between handlebar and front wheel were subject to easy scratching on standby, because of lack of any bumper - they could hit directly the frame. This is where this design comes from. But to be strict - I do not guarantee, that it fits exactly to this motorbike, because this colleague (who asked me to make it 20mm internal diameter) sold this motorbike before I printed this part :) So if You need it for Bagira - please check the diameter and if needed - scale it up or let me know.