I cruise at 8000rpm, thats just over 60mph (my front sprocket has 1 too many teeth though). If I cruise at 9000rpm it seems to be a bit vibey so I tend to avoid that. With the higher gearing it doesn't tend to go over 170kmh, though my dad clocked me at 120MPH downhill once! - WAY off the end of the speedo, gotta love that baby 4 cyl howl
On Bridgestone BT45's, front is 33psi and rear 36psi i think