How well-known is the word 'wheelie'?
I'd say wheelie is very well known in the U.S. Most kids grow up doing wheelies on their bikes or watching someone do it.
According to Wikipedia, wheelies have been widely known since at least 1943, and they were further popularized by Evel Knievel.
Wheelie is well known in Australia. BTW: the opposite of a wheelie is a stoppie, that is when you apply the brakes sufficiently hard to life the rear-wheel off the ground. Tends to apply more for motorcycles.