Tire pressure ain't all that precise... don't worry too much...
As long as you're between 26 an 34lbs, you're in the park... (higher for 2-up, or if you're a big fella',... lower if you're a scrawny rat)...
Mine gets down to below 20lbs before I catch it... then I bump it up to 32lbs, and let the process begin again...
Car tires are more critical... they are designed to run with air pressure that lays the tread flat...
Bikes don't ... the tread is on a curve... the center always wears out before the the sides...
Air pressure only reduces sidewall flex... if your load weight is making the tire squirrly in corners... you need more air
Less air, gives more traction... and a softer ride... less chance of a blowout...
More air,... will give better mpg's... and less unsteadiness in a corner... less heat, but less traction...
All this matters... if you are Rossi... or pretend to be...
Otherwise it ain't that crucial... it's what feels comfortable for you... (the darn bike tires are going to wear out way too fast anyway)....
JMHO...
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