mike-s wrote:
There's also this post, which says in part, quoting Maxxis...
"High Speed" is used to differentiate the M8008 ST Radial from other products we offer that are intended for industrial and/or commercial use, in slow speed applications. The Maxxis M8008 ST Radial carries a "Q" speed rating. However, according to the Tire and Rim Association, the U.S. tire industry specification authority, inflation pressures and load specifications in general for any ST Radial trailer tires without a service description, regardless of the manufacturer, are designed and rated at 65 MPH. ...
Followed by the 10 psi / 10 %, etc. adjustments you gave. The discussion which follows ignores the "in general" qualifier. I read the response to be that the Maxxis M8008 is Q rated at full load, but ST tires which aren't specifically rated like the M8008 ("in general...without a service description") can follow those rules.
That's nearly the exact response I received over the years, with slight variance.
Question is, who in their right mind is running their ST tire at less than max cold PSI on their TT? Gotta be crazy not to.
I will not believe any speed rating unless its molded into the sidewall. Period. Like this, on my Carlisle HD's;