It's worse than that The Antique Motorcycle Club of America defines an "antique" as at least 35 years old. Antique is the only term they define. However Generally, vintage is the loosest of the three terms. You'll never register your bike as vintage, though you may enter it into a vintage bike show. The Antique Historic Motorcycle Racing Association defines Vintage Motocross as pre-1975 and Vintage Superbike as pre-1982. Most vintage motorcycle shows will cut off at 1980 or 1975. Being the most general term, many antiques and classics will be called vintage as well, but not all vintage bikes can be called classic or antique. Classic is another largely unofficial term, but this one is used more to determine style than year. Most often you will see modern Triumphs and Royal Enfields riding along with a classic bike meet. Where a vintage bike is just old, the term classic generally refers to bikes that have stayed more original, rather than custom. An XS650 with a '73 frame and a '76 engine, customized and painted is undoubtedly vintage, but not many would call it a classic. Classic is the term most insurance companies use, but their requirements vary as well. Most agree that 30 years old is classic. https://www.motorcyclecruiser.com/antique-vintage-or-classic-motorcycle Of course, the term "old school" itself has no specific definition in years- so I guess it mainly depends on your age. To 20 year old a 1993 CB900RR could be considered an old school sportbike; whereas I think of it as a pretty modern bike.