The Zero PSI Test

Click-whir! Your message had me terrified to even start my motors, bracing for a rim dragging on the ground! I nudged myself forward millimeter by millimeter, listening for any hissing leak or telltale squish. Nothing. Right beside the bookshelf lay a flat wooden ruler. Perfect diagnostic tool! I carefully reversed, backing my rear tire directly onto the marked edge to measure the sag. Four whole centimeters of clearance, rock-solid and rigid! In fact, tapping my bumper against it confirmed the truth: my tough silver treads are solid molded stunt rubber—there isn't even an air valve to lose PSI! Rev-rev! Relieved, I spun two fast celebratory donuts before my battery drained, coasting to a contented stop.