32/34psi............:eek1 I tried a little over 20 ft and rear in my DR650 once due to rocks and weight of bike. I had to stop and let some air out,there's no way to steer a bike in dirt/rocks with high air pressure. Just a few lbs makes a difference,around 17 was ridable. I run 5 psi with the Tubliss rear trials tire on my 200XCW for local singletrack,it will climb anything I point it at with near 0 wheelspin and goes through rocks straight as can be. It routinely goes by other guys with knobby tires who havent tried the Trials tire yet. But,Knobs are great for some stuff,Trials tire great for others.