In fact, in a few certain situations you can actually purchase higher-end hardware than the pros use. UCI has restrictions on shape and weight that need not apply to non sanctioned riders, and there are improvements that are available in both aero and weight. Notably, Triathlon specific bikes are often markedly faster than UCI compliant bikes due to the aggressive aerodynamic optimization.
Strictly speaking, the show is somewhat based on a series of novels. There’s an awful lot of story in those that is simply not present t in the musical, but could possibly have been included in the movie. I don’t know if that’s actually what happened, but there’s certainly a canon source for substantially more content.