The pressure in the owners manual is for stock tires, most people change tire types once the OEM's are gone. Pressure on side of tire is MAX air pressure, you don't want to run that all the time. For Dunlop E3's I run 38 f and 40 r
I was confronted with the same question. When I picked up my '95 Aspy from a local dealer he inflated both tires to the pressure marked on the tires. The bike just did not handle right. I was convinced that the tires were over inflated. Note that the pressure marked on the tires states - - for max load. Therfore I adjust my tire pressure between the placard pressure recommended and the max load pressure as marked on the tire (cold). I do not ride 2 up and presently have no other load than myself at 155. Additional note my Dunlap tires are spec as OEM replacements!