Vintage motocross is motocross racing with vintage bikes. In a nutshell before 1975 is considered “vintage” and 1975 to about 1981 is called Post-Vintage. I like the Post-vintage era because “in the day” that is what I rode. My 1978 Husqvarna 250 CR is a classic example of a post vintage racer.
get started you need to find a bike. You can go craigslist and get a working post-Vintage racer for as little as $500 or up to a fully restored model in the area $3500 or more.
I went the way of finding a non-running Husqvarna and attempt to restore it. It has been tough task since I have no mechnical skill at all. The bike needed a new clutch, rebuilt top end, new tires, plastics, kickstarter, and it still dosen't not run right lol. But I only paid $250 for it. Moral of the story is I have put out way more getting fixed up enough to race then if I just found one running well in the beginning. Get one that runs well.
Once you have a bike and safety equipment such as motocross helmet, boots, etc.
. You can join a local Club that is associated with AHRMA, AVDRA or local independent clubs. Check this video out is shows real well what vintage racing is all about: