Back in the mid 1980's my tubeless slicks used to loose air, some racers told me the air seeps threw the rubber, take a thin layer of dish soap on inside of tire and rub it around, it fills in the porous holes. It worked great, held air on a couple different sets. Don't remember if it was "DAWN" or "JOY" they said to use now, but it does work. Hope it helps as a different option. -Jed.