Continuity mistake: In the scene where Dave is racing with the Italians, when the Italian puts a pump in his spokes, Dave's hands are off the bars, the front wheel slides out to the right and the bike falls to the left. Immediately afterwards, you see Dave with his hands on the bars, the bike is still upright, and then he goes forwards over the bars.
Continuity mistake: At the end of the scene when Dave races with the Italians, the bike he is riding when the Italian puts a pump in his spokes is not his bike. His bike has a chrome plated fork crown, and brazed on shifters. The crashed bike is a cheaper bike with a cheap fork that has no chrome, has paint missing on the inside of the right fork blade, and the bike has clamped on shifters.