Select comfort mattress is not a tire. You're getting this messed up again... putting load on a tire isn't about compressing its volume from an external source.
Hey man, just trying to tell you how it works. It's for your own benefit, not mine
I fully encourage you to discover this on your own, not just take my word for it. If you've taken some undergraduate engineering classes you're probably familiar with the 'method of sections' for solving statics problems. I like something similar for analyzing this particular situation.
The net vertical force on the rim is the only thing we're interested in, in terms of carrying vehicle load. Picture an inflated, loaded tire and rim assembly. Make a "virtual" cylindrical cut from the side, about halfway up the sidewalls, and exclude everything from that cut outward toward the tread.
Hell, I'll even provide a picture:
Consider all the forces acting on the rim. Air pressure certainly does exert a force, uniformly in all directions. As such, the air pressure cannot exert any net force on the rim. Integral of air pressure normal to the rim surface, over that surface = 0.0 lbf, thus carries no load. Since the only other thing in contact with the rim is the tire itself, 100% of the load must be supported by the sidewalls. QED
Not one man's opinion versus another, just how it works. For what it's worth though... it's very very dangerous to take what someone says as the gold standard regardless of what their name is. Doesn't matter if it's me, or Steve Matchett, Doug Milliken, Claude Rouelle, Ross Brawn, Chad Knaus, Carroll Smith, Paul Haney, or
anyone. When people do that it perpetuates a lot of BS. If someone tells you something, sort out how it works in your head, and if it doesn't jive - figure out the real answer.
It's a huge sticking point among young engineers, particularly in FSAE. Example dialog-
"So and so says this is what the suspension needs to do."
"Yeah? So what? Don't care what he says,
you explain to me why that's the case and why it isn't just BS"
"..."
Grip is a four letter word. All opinions are my own and not those of current or previous employers.
