I had a pretty catastrophic failure on my commuter bike back in March. My fender became wrapped around my front wheel, stopping it, and sending me flying over the bars on Forbes Ave right in front of CMU. Luckily I wasn’t hurt and there wasn’t a car right behind me.
When I got home and untangled the fender and its supports from my wheel, I realized the bike felt a little strange. Although it wasn’t severe, the front fork was definitely bent. I didn’t hit anything, mind you, I just had a metaphorical gorilla grab my front wheel and stop it suddenly.
I was surprised by this, and spent some time looking around online. Much to my delight I found an article by an engineer who is an expert on such matters: John Forester. I publish it here mostly as a reminder to myself as I find it to be quite interesting that there is a way to generate enough tire friction with the ground to bend the fork instead of “pitch over”.