A stowaway! Egads!
Once I was able to loosen his surprisingly vice-like grip on my brake cable (which explains why he was able to hang on during my blazing sprint), I released him into the yard to start a new and exciting life in a different part of Des Moines.
(Astute readers will note the use of male pronouns above. I have no idea if this was a he or a she, I had no idea how to check, and even if I knew how to check, I'm not emotionally equipped for that level of insect intimacy. Call me a tool of the patriarchy, but I figured that a bug dumb enough to participate in the extreme sport of bike-surfing was probably male.)