I wanted to see if anyone could recommend a good GPS system for a bike. My b/f has a custom rigid frame motorcycle, which vibrates, a lot. I know there are two systems made specifically for bikes but does anyone know if they can handle the vibrations from a rigid frame, not to mention the jolts from hitting any pot holes?  

Any solid-state model should be good no matter what the vibration. just dont try any DVD or Hard Drive-style "spinning" style GPS systems