2 Cyclists and a Fly

If there are two cyclists twenty two and a half miles apart miles apart and they are going to cycle towards each other on a straight line. The cycles are travelling at eleven and a quarter miles per hour.
On the handle bar of one cycle is a fly who's job it is to at 90.2 miles per hour from one bike to the other, and back and forth until the bikes meet.

How many miles does the fly fly when the bikes meet?

Answer <--- click here