That is very cool Wren. I have two friends on the Washington DC roller girl team. One goes by the name "Roller Brat" so that is taken. How about Suicidal Roller?
first thing that popped into my head was "badger" too. perhaps preceeded by your real first name.
"...and coming around the fourth turn is fierce little [ ................... ] Badger. we don't know what her plan is, but skaters tumble when she and her flames head for a hole in the pack. what a killer fierce [ ................... ] Badger is!"