I rarely recommend a specific tire pressure for street riding as it truly is a matter of preference. Higher pressures will increase gas mileage because 30 psi creates more friction and drag than 42 psi and the tire runs cooler in all conditions making the tire last longer. But,,,,,,,,,,,,,,,,,,,, and this is a big BUTT, you gain another mile or two per gallon and a little more life at the expense of traction. Your choice.
I can tell you that my preference for my busa on a trip or a long day ride with my friends is 36 front 34 rear. If I'm going to romp the twisties with my buds I drop a couple pounds to 34 front 32 rear on Q2's. However, for the most part my busa has a Q2 front and Roadsmart rear (Which I prefer by far over the high mileage Michelin PR series). The Roadsmart is a happy medium between the Q2 (Which is basically a race tire in street form) and the high mileage of a PR3. I still get knee dragging stick from the rear and improved mileage over the Q2. Best bang for buck for street use in my view. This combination I run 36 front and rear for the life of the tires.
I never run less than 36 psi cold in a touring tire, front or rear. I don't want the stiff carcass to have excessive flex and should never have less than 36 psi cold.
