Did you know that tires have the production date molded into the sidewall? The production date is a four digit number, the first to digits are the week of production, the last two are the year (e.g. 4017 would be the 40th week of 2017). So even a “new” tire that is old is still no good. What happens is that the solvents that make the rubber pliable start evaporating the molment the tire leaves the mold. A tire that is unused but six rears old I’ll have reduced traction and be prone to premature failure. I run a fleet maintenance operation for a living, and my policy is that we only install fresh stock and that tires get replaced after four years in service, two years for rideshare and field research vehicles, no matter what they look like. I’m not going to be at home in the evening watching the news and see one of my vehicles on it’s roof with it’s occupnts strewn all over the desert. The reason I bring this up is that I was picking up a rear tire for my CR500R yesterday and found a Shinko with a nice tread pattern, the price was fantastic, but it was to years old... pass, it was already turning to stone. If I would have put that thing on the bike it would have spit half the knobs off the first time I got on the gas. Check the production date before you buy.