Is your chipper direct drive? I don't even think mine has shear pins, but then mine is belt driven. I think for me, the damage will be to the belt or PTO, and the belt is no cheaper than the blades.
I saw a Goossen version of my Bushhog chipper/shredder on-line for sale this week. Overall, the unit looked to be in really good shape. Then I noticed that the rubber shield on the shredder was also tearing apart. So, perhaps I didn't abuse mine afterall.
Anyway, got my SBR material this week to make a new one. The SBR with reinforcement is way stronger than the original - can't tear it by hand. It also seems to be heavier in weight. We'll see how it holds up. But, I will make it a point to store it out of the sun, and will probably even cover the hopper with black plastic when not in use.
Gonna be too hot today to work the chipper very much though.
No pics. Too busy working, I guess, to go get the camera. Maybe I'll remember to do that next time.
Anyway, put new chipper knives on last night. Not too bad a job. Took about an hour. Haven't tried them out yet. Will post when I do (and hopefully some photos too!
I plan to get the old knives computer resharpened. Then I can keep a sharp set around when I need them.