'05 800, I gave the shop my front and rear wheels and the Michelins had them do the swap, they reused both tubes and I think they are OEM tubes because the rear I am checking now has the 90 degree metal stem, so this was a few month ago and they set the pressure on the rear at 35.5 psi. So 2 weeks I used one of my expensive digital tire gauges to check pressure on the rear and it was at 35.5, then a couple days later I was about to go for a ride and the rear was completely flat as a pancake, so I thought bad valve stem? hole in the tube? but the psi was fine on the rear for 2 months after shop did it so can't be a hole in tube, so I thought it must be either the valve stem or that digital tire gauge I used, so I replaced the valve stem with a new one, and also I checked over my digital gauge and noticed the metal pin on it that pushes on the valve stem was out of line and loose, so I bought a new pressure gauge, pumped up the tire and checked it on Friday using this new gauge and I put 35.5 in the rear, today I checked it again (not using my expensive digital gauge anymore) and it's at 35.0 just now, does that sound like I got a leak? or should I wait a few more days and check it again. I have a sense that my expensive digital car tire pressure gauge I bought off ebay has bit the dust and is broke and side-swipped the valve stem pin to remain out of line enough to let out the air. Dunno what happened.