For me It began with Hell Ride, and goes back in time from there -- I usually work backwards and try discovering the origin when I find some kind of art that interests me.
The biker movie genre typically showcases a strange time in American culture, a culture divided in the middle of the 20th century at war with itself, struggling to be reborn or in the case of the 1%, to completely disregard conventional structures of culture. Growing up in Southern California long after the so-called revolution of the 1960s and 70s and often hearing about the terrors of the Mongols and the Hells Angels, my interest in the subject of MC gangs piqued with my foray into modern American Literature known as Hunter S. Thompson and his book, or profile of the Hells Angels as they made their way across California during the 60s.
The films are by no means documentaries on the subject, usually serve to bastardize and fictionalize the MC gang sub-culture. Often portraying them at odds with the so-called squares or city people, the law and everyone else. They are mostly entertaining, combined with music and geographical backdrop of California of the time.
Here's a list of some that i've found on Netflix streaming
Of course, I'm not including perhaps the most famous biker film, The Wild One because it's not available on Netflix streaming and I still have yet to see it.