Here is an interview, from a magazine database my partner and I built.
"Edwards had loaned me his Rolleiflex—that was the first 2 1/4 inch I used. And I must have taken it south, because some of those pictures are square format. I had a funky old Leica M2 that scratched every picture. Eventually, the Nikon F would be my real workhorse. With The Bikeriders, I didn’t use a Leica. It was a Nikon Reflex, that early, single-lens Reflex. It was such a fabulous camera with a prism on it—no light meter. I had a 2 1/4 inch for The Bikeriders also. When I got to Manhattan in 1967 and realized what I was getting into, making architectural pictures, I went to Olden’s on Broadway and 43rd Street and got the cheapest view camera you could get—a Calumet."