Because those early Harleys had a hand shift, the rider had to have a foot clutch. It was easy for one's foot to slip off the clutch and, if the motor was running and the bike in gear, it could lurch forward a number of feet. This was extremely dangerous at intersections.

When I was a bike rider in the late '50s it was not uncommon to see a fallen rider lying in the middle of an intersection.

The American Motorcycle Association, founded in 1924 (and "whites only" until the 1950s).

If they were a motorcycle troop, they had a name. I wish John Collier had captured it so we would know if we're looking at the South Side Devils ... or the East Side Demons.

[It's right there in front of your nose! - Dave]

You are correct. I was thinking of something more rebellious. As best I can make out, the name on his shirt is Bridgeport M.C., so they rode about 75 miles north to see the foliage. The patch has a nice, sort of Art Deco style.

... because if it was taken today, the dude would have a seriously huge gut.

["Definately"? Sic! -Dave]