This is an experimental design that proved difficult to print well. For a more successful subsequent design, see my Micro Fender for Bicycle Rack.
Inspired by the Genetic™ Carbon Micro Fender, with the same 40° coverage, but meant for wider tyres and to mount on my bike's seatstay bosses. My bike is built on one of Vélo Orange's second-generation Pass Hunter frames (circa 2020), which support 700c tyres up to 35mm wide or 650b tyres up to 48mm wide. I use 700c, but I've included STLs for both options. For any other variants that you may require, recompile in OpenSCAD with different parameters.
The author marked this model as their own original creation.