Quick Question. I have an XT225 for trail riding. Since I ride about 80% on dirt trails and only on the pavement enough to get to trails, I have put straight dirt tires on the bike. FL sugar sand is cruel. I have Michelin 90-90-21 on front and 120-90-18 rear. For the life of me I can't remember what is the best tire pressures to run with this bike and tires.