Low rear tire pressure - help finding cause??
Cheap helpful bandaid for a leaky schrader. A good metal valve cap with a gasket seal. Tighten it down firmly and the seal can hold pressure. Don't use a cheapie metal cap made of aluminum or such. They can corrode, which creates it's own problems. But a good one made of stainless, that can be a wonderful thing.
Bonus, you can find them frequently with the valve stem tool built onto them.
Trust me, you will feel better when you fix the thing and ride.
Time to stop thinking, just fix it and let the good times roll.
You should find out if the PO used Dyna Beads. Not getting into a discussion on if they are good or bad. I had the same issue you had on a new tire replacing a new tire that picked up a razor knife blade. I usually put a finger of spit on the stem after air up to make sure there are no leaks but I missed it once and sure enough there was bead trash in the core. One hit with the air hose cleared it and no more leak down. If you have them try not airing up with the core right at the bottom. As little as 25 degrees forward or back will prevent the air rush from disturbing the beads that are laying in the bottom of the tire. If you have straight stems you can put filter cores in to prevent it but if you have 90* stems the filtered cores are too long.
Changed out the core, aired back up, and took it for a test ride. Checked pressure again when I got home, and it had picked up 4 psi. Even managed to get the 'crap that's hot' muffler burn on my wrist trying to snake the gauge back in there after the ride. Doh.
Thanks to all of you for the input and ideas, it's much appreciated.
Dan.








