I've ridden on older tires than that, I once bought an 50's Schwinn which still had its original Goodyear tires, and when pumped up, they still held air. But the sidewalls were somewhat rotted, and the tread had cracks all the way around. I guess in the 50's they made things to last. But riding on such tires is not safe, and with tires and tubes as cheap as they are, and with emergency room visits more expensive than ever, it would be wise to replace the tires.