1. A BMX bike designed for racing over dirt tracks. They are lighter than other BMX bikes. They are fairly cheap but give their owners, usually boys in their teens or younger, a sense of status and pride.
2. Any road bike of reasonably light weight. This is sometimes another use of the term "racing bike" among teenage males. Although real cyclists would laugh at this definition, any decent road bike is much better for road racing than BMX racing bikes.
1. "Hey, want to race? Let's go down the dirt road a mile and back."
2. "Racing bikes are so awesome. They are so much fun to ride on the roads."