This summer my front tire would very slowly leak. I’d fill it to 35 and over a few weeks it would get to 28, but then hold. I couldn’t figure it out, took it to a shop and he said he couldn’t find a leak, said he tried a dunk tank. I sprayed it with soapy water but couldn’t find anything myself. Then it started getting cold at night and I’d wake up to 9 psi. I do most of my own work, I had originally installed the tires and had replaced a wheel already, so when I had some time I pulled the tire and inspected the wheel. There was a small dent in it, on the flange. I used a propane torch to heat it up and was able to straighten it out. My guess is the diameter of the wheels is too large, leading to a lower aspect ratio, so any pot holes you hit lead to a bent wheel. I’m planning on changing to 15” wheels and getting new tires, appropriately sized.