The file 'Aggressive Pin-spike Tires 3.8" 3D Printer Model' is (stl) file type, size is 3.6MB.
here they are!
a pin-spike tire for 3.8 wheels, similar to the old Pro-line Mulchers. I have only tested them on my dish wheels (https://www.thingiverse.com/thing:6587922) but they may fit on most 3.8 rims.
these tires do not have good grip on smooth surfaces, but they absolutely tear it up in loose surfaces!
pinspiketire38.stl | 8.3MB |