When the info was released that a Bike was originally in the game, we where more or less told/led to believe it wasn't fully functional, and was hard to keep it steady(infact I recall seeing footage of such a while back, showing it was pretty hard to ride/it wasn't fully functional, when this came to light).
Well I decided to do a Youtube search, to see if a Beta version of the game, with the Bike actually surfaced(opposed instead of just the footage I have seen already), and found such pretty easily.
https://www.youtube.com/watch?v=f9XQsX5QAKs
As you can see, the bike seems to be fully functional here, It's not the clumsy mess we may have seen in the past, so if it was a already fully implemented system, why was it cut, I wonder?
Someone so needs to ask Yu about this(while they're at it, ask him how he fit Shenmue 2 on just 4 GD rom discs as well).