I've played with tire PSI a lot with varying loads on and off road
on two Commandos and a SV650.
I also settled on standard 2-3 lower front than rear pressure as best,
then air up or down for the surface or load carrying behavior.
This is important - that the front has a tad more compliance
than the all important rear tire planting for lean and aim.
IF not the bike will seem to fight your inputs and
twitch on road texture and fork following road surface.
28-32 is common ball park to work around general usage.
Ideally we are told to check PSI when tires warm as they'll
get then diddle PSI so pressure rises ~10% -2-3 PSI heated.
I can't tell you how valuable a lesion it is for maxed out
bizerk racing or to avoid a flat tire surprise upset cruising,-
to let more and more air out front to sense the strange action
and then air it back and repeat on rear, then
soften both at once. Only takes a few 100 yds each
going rather slow to feel what I mean.
A blow out at speed going straight can feel like just
a bit of wind gusts, TIIL you slow up or enter turns
WHHOOHOOO, Worst bucking happen just before
about to put a foot down, WHHOOHOO>
If you know tire is flattening then about any one can
ride it out, but not if surprised because our normal fork reflex
brings on suddenly opposite dramatic reactions.
hobot