There is no such thing as a GOOD old tire , I've had lots of belts let go on tires that were over 5 years old, two years ago I was pulling a loader on a trailer behind my 2500 truck It was a E rated Michelin and when it blew at 45 mph It cracked a forged alum wheel ripped off my wheel flare and bent up my rear fender, lots of tread left
This spring I was going to a boat race started to feel a vibe pulled over right away front tire belt shifted the tires looked brand new , I bought the tires and wheels cheap last year $1,000.00 the Guy is a very wealthy said the wheels had too much offset , for his new truck, stuck out too much what a deal! tires list for $460 per tire and 20" x 10 " new wheels what a steal ! I never checked the production date on the tires

old tires are JUNK tires , I would have used the tire up, I NEVER want to be on a bike when a tire gives out , a slow leak no problem a BLOW out OMG.