Originally Posted by KBR97
Do you have onboard air?
If you don't, I would start around 20psi and work down from there till you find the PSI that works for you. All the answers you get are just peoples opinions on PSI that works for them, on the specific tires they have, on the specific trails they run. Its more a matter of opinion rather than fact.
What he said^^^ ... except IMO start at 18psi and work down. 9psi make be great for MTRs, 12psi may be great for BFGs, and even 15-16psi for others. But, you'd need to go to 5 or 6psi to get the same flex out of, say, a Michelin XZL.
It really is tire dependent-