That depends on the venue/district/organization/etc. I've seen a few different criteria. Check the club you want to run in. AHRMA has a website that has all the rules. In Michigan the D14 vintage series they start at 1974 and older for Ironman and 1981 and older for EVO. So, in this state, with aircooled engine and drum brakes it would be EVO.
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.