So i've been a 120psi front and rear because it's easy kind of guy since I bought my first bike in June. Ive just recently heard mention of a few people saying that depending on your weight, you should ride at XX psi instead of 120psi. Can anybody explain this to me? I'm right at 5'9 and 160 lbs. so I have no idea if its better or worse to ride at 120psi f/r.

Thanks in advance for dumbing it down.