I fine tuned my search on the LIFE archive and focused on the Loomis Dean 1949 motorcycle pictures. It seems he did an in depth expose of motorcycle culture around Los Angeles in 1949.
Here are some I have not posted before.

Booze Fighters MC in the lead

Unicycle

Three Point MC

Indian Vertical Twin

SO. Cal. MC

Speedway bikes with an inverted negative

More speedway


Tattoos and tramps

Biker Chickie


group of chicks

Big Air AJS


Chuck and his fender fluff



Chuck should think about some eye protection

Hollywood MC (notice trailered bike)

Mustang

Curves with HMC


Dirt of Glory

Climb the Hill

Proud of Racer Pop

Powder Puff Race

Excelsior Thumper

Happiness

Straight Outta Compton

All of this and no Harley-Davidsons. What is the story with that? Did only LA cops ride Milwaukee back then?
Later,
Ray in CT