the sidewall spec is the max pressure and you'll wear out the center of the tire if you run it at that. My sporty specs are 36 rear 30 front, and I ride two up a lot. I kept the pressures there and the rear is wearing in the middle. If I had gone to around 29-30 on the rear it probably would have worn more evenly.
I don't know how smart it is but I also tend to let the weather dictate. If it is going to be wet for a while I tend to run the pressure on the low end. If it is going to be Houston Hot as Hell, then I take it to the high end. There is an acceptable range and I let conditions detenine what end I am on.
"stamped on the outside of most motorcycle tires is a is a recommended tire pressure range, usually an upper limit. For longest tire life, you should strive to keep air pressure AT THE HIGHER limit. The pressure should be determined while the tires are cold, and nd not been used for a couple of hours.
The article goes onto explain that it is normal for a tire to lose about 1 pound/sq.in. per month and that outside temps. affect tire pressure. Tire pressure can change 1 psi for every 10 degrees F. with an example: a tire with 38psi on an 80degree mid summer day could lose enough air to read 26psi on a 20degree new years day. At 26psi, your tire is severly under inflated and dangerous.
It goes onto expalin reverse logic for winter.
I have Dunlops on right now but will be getting the Avons very soon. I wounder what the manufacturer's recommendations are.
(remember the Firestone/Ford problem)
For now i'll stay with the HD specs because I personally would rather have my tires a little underinflated than over inflated if I had to make a choice.