Tyre Contact Patch
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:-120-160………………….15% 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
Notes added by Y-G
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 :-}