QUOTE (Lindt @ Nov 11 2011, 08:28 PM)

Open assumption. Odds are its even more. I was just picking a number to do my math with.
The calculation you're doing, though, seems to be comparing modern commercial tires with what's basically a modern commercial tire so low-profile that there's no pneumatic pocket in it. NPTs are seldom like this, and only in the lowest-speed applications: rubber [or what we call "rubber" when we put it in a tire] can't dissipate heat quickly enough when it's laid in a layer that thick, indeed much of the reason why all passenger tires aren't NPTs.
I guess my point is: why "pick a number to do math with?" The number's almost certainly
crazy wrong, so your math's going to end up being at least as crazy wrong. [edit: Which is still short exactly one explanation of why I chose to pedantically interrupt you, sorry. Let me give that a shot. The thing is, NPT technology in Shadowrun is so far out there in terms of NPT technology today that our common sense ideas (read: assumptions) are just completely incorrect. Now, that's
always true in Shadowrun, so it's inescapable, but putting
precise numbers to something that's not even close to precise is a good way to come to a terrible conclusion. It seems to me like, if you really want NPTs in Shadowrun [not sure why] that aren't Smart Wheels, you should be prepared to be vague: "NPTs will probably be at least a little heavier, and unsprung mass is a killer on handling, and weight is a killer on acceleration and braking. How about a -1 Handling, and some kind of penalty to Acceleration and top speed (due to heat dissipation)?" In short, I'm not saying your
idea is wrong, just that inventing numbers to have numbers generally isn't that productive.]
QUOTE (Draco18s @ Nov 11 2011, 08:39 PM)

The density of air at sea level is about 1.2 kg/m^3
The density of Rubber, soft commercial is 1100 kg/m^3
Maybe this is a common misconception, then. NPTs aren't just "tires with the air replaced with rubber." [Or, as above, "tires with the air replaced with more rim," which is a better solution, but still not practical.] There are a number of different NPT designs, and none of them [for automobiles] is just a solid blob of rubber on a car rim.

Whatever Shadowrun NPT designs would be, they're almost certainly not going to involve "rubber, soft commercial," or even its equivalent. [Of course, Shadowrun has no need for NPTs, since its run-flat tires are effectively NPTs anyway, but...]
QUOTE (Draco18s @ Nov 11 2011, 08:39 PM)

...air is generally pumped to about 60 PSI...
In a
passenger car tire? I don't put 60 psi in my
racing tires!