Since pretty much every American company stamped their own drop outs, looking at the drop outs is a good way to identify the manufacturer of a bike.
However the companies all used different styles through the years, so I thought it'd be useful if we could post examples from different companies through different eras to serve as reference.
This way when somebody comes across an off brand bike, or one missing its head badge they can look at this thread and figure out where it came from in a minute or two.
I'll start with a few pictures I have:
AMF 1970s:
I think this style was only used on their lightweight frames.
Columbia 1948 onwards:
They made other styles of drop outs too, but this is the most common one from 1948 on.
Huffy mid/late 60s? onwards:
However the companies all used different styles through the years, so I thought it'd be useful if we could post examples from different companies through different eras to serve as reference.
This way when somebody comes across an off brand bike, or one missing its head badge they can look at this thread and figure out where it came from in a minute or two.
I'll start with a few pictures I have:
AMF 1970s:
I think this style was only used on their lightweight frames.
Columbia 1948 onwards:
They made other styles of drop outs too, but this is the most common one from 1948 on.
Huffy mid/late 60s? onwards: