On 10/31/2018 8:23 PM, wrote:
ok! if we pretend a scale where 10 is brand new tire and 1 is all stiff with visible cracks. on the tire it says max X psi. when the tire is worn down to say 5 on our scale, can it still take X psi? why/why not?


If you mean normal aging and degradation of synthetic butyl
rubber over time, that's mostly irrelevant to pressure rating.

The nylon carcass doesn't degrade and the bead lip at the
rim is protected from ozone and UV so it will be intact long
after the tread has dessicated and crumbled.

Would you want to corner hard on a dried hard cracked tread?
Probably not.
Will it hold rated pressure? Sure.

If you want to discuss injury/damage to casing or bead,
that's another discussion entirely.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971