A few years back, I had left an old road bike in a closet for literally 20 years. Old enough it wore 27x1 tires. Pulled it out, figured it wouldn't hold air, pumped it up. Rear tire was flat spotted and appeared to take a bit of a set. Left it inflated overnight, and the set was gone. Cleaned and lubed other items on it, figured the tires would never last at all. Road it a couple hundred miles over some weeks with no issues.