On Tuesday, March 13, 2018 at 9:54:46 PM UTC-4, wrote:
... The original tire is hard as a rock with zero pressure.

- exactly, the original tire feels hard even with zero pressure, that's why I learned to check it with a pressure gauge every couple of months. Despite the hassle, as (on the AC4a) I need to remove the wheel fairing, and add a valve extender, just to use the gauge. But the alternative is a ruined tube, or worse.