How durable are these frames? A friend had one in high school. The frame broke. His father took it to a machine shop for repairs but it broke again. Granted late 60s aluminum repair techniques were primitive. He was a big very strong guy, all state footballer. He and I did a lot of cross country skiing and he broke 2 - 3 fiberglass or cane poles each season double poling. He finally went to aluminum poles. I think he actually folded an aluminum pole. So upon reflection, it’s only natural that he broke the frame.