Hello, The rear tire on my GG - an older Michelin Trials X Lite - occasionally looses its pressure. I normally run at 4.5 PSI. I'm a recreational rider. I just thoroughly submerged the tire in a tub of water and noted no bubbles from the tire nor the valve stem nor the spoke nipples. Is it possible for the tire to loose air when it impacts an obstacle (say at the bead)? And the tire did come with a "slimey rope" plug in the tread area (i.e., not on the sidewall), but that also does not appear to leak (in the water at least). But perhaps that plug is compromised when the tire is distorted under traction. I even increased the pressure to 20 PSI and no bubbles were noted. So can a tire leak during its normal operation? Is there a "fix"? My current fix is to simply carry a pump. :) And can a vulcanizing patch be applied to the inner carcass as a replacement for the slimey-rope plug? Thank you.