My tires lose 20 pounds after a simple 15-mile ride on a paved bike path. It's easy riding. But they always lose air. My girlfriend's bike tires also lose air. All bike tires constantly leak air, right?
I have Bontreger Hardcase Race Light tires. There's an inner tube, which I would think would keep air in. Unlike car tires, which don't have inner tubes, yet never lose air.