When radials first came out for public consumption we were told by the tyre techs to run pressures for the rise in pressure from cold to hot…
sizes up to a 120 width tyre……..10% rise
sizes :- 160 and up..the percentage is one tenth of the width (160..rise 16%…180-rise 18%)
These were recommendations for best wear and grip….other circumstances may warrant alterations.(ie carring a passenger ) I routinely run less than the above when roads and air temps are on the cool end…just for tire warmup and compliance. I think it's worth experimenting for side wind handling.
Above Notes By RR
One trick is to go ride the bike get the tyres upto temp and then ride thro a patch of sand thrown on a smooth floor and see how wide the sand patch is on front & back tyre. At 180 lb in body weight of rider and hot tyres I like to se between 1.5 - 1.0” sand lines on the tyres. Measure the pressure HOT
If you do this again when the tyres are cold ie look at a fresh sand line on the tyres & measure the tyre pressures you will get what is right for you.
Remember that “THE BOOK” is only a recommended pressure not what is right for you.(you may weigh 140lbs all wet or 280lbs bone dry :-}