check M/Ts recomended air pressure
on my M/T sportsman pros 29x15.5x15 they only held 20lbs max
on the street a full 20lbs was just right
for launching,droped down to the 12lbs to wrinkle the sides and they hooked big time...looked like it was almost flat,but it would wrinkle and stand up on the launch...a little scary on top end as they would wiggle some at top speed
the new M/T sportsman SR radials 29x15x15 I just got use 25lbs max air pressure
lot harder rubber compound and stiffer side walls for the street
I run them right at 19lbs to clean the tred all the way across the foot print
they do much better in the rain with the flame tred also
have not let pressure down on them as they hook good on the street right now
but we will see when they go from sb to 440 truck
I dont think they will drop very much,maybe 15-16lbs is my first try on the tire when I adjust them on the 440 truck
and did I mention the et streets and the sportsman/sportsman pros hydro plane real ez in the rain...I could not drive over 40mph with them on a wet day
the SR radials kick right on down the raod at 55 when in the rain,have not had them plane yet...but I keep it down anyways so not too