My first tire blow-out found me
Northbound on I75 just outside Tifton Ga we had a rear curbside trailer tire detonated with a load bang and lot's of rubber flying out behind our trailer. The H-rated Sumitomo 17.5 tires were just ov...
Forum Discussion
gitane59 wrote:
To everyone else running 17.5 H-rated tires on fifthwheel's in the 16K lb weight range what air pressure are you running in your tires.
125 psi Cold Inlation Pressure, which also is the tire sidewall maximum. Yes, it is more than what a load table would indicate for the trailer. I am unconcerned about "trailer ride". Only inanimate objects ride in the trailer, and the springs and shocks do a credible job.
Why maximum pressure? To reduce the incidence of interply shear that is an attribute of multi-axle trailers.
Roger Marble is a tire engineer:
"For multi-axle trailers I would consider improved durability, i.e., reduced chance of failure, to be of primary importance. So in this application, the "optimum" inflation pressure would be the pressure on the tire sidewall associated with the maximum load capacity. Even if you are not loaded to the max load you want to lower the "interply shear" forces as much as possible, as trailers induce much higher shear forces than seen in similarly loaded tires would if on a motorhome."
