|1961 Lorain Phone Book ads|
From what I could see, it was just Atlas Cycle & Supplies on E. 28th Street in the late 1950s (it was the only company listed in the 1957 book.) It was briefly joined by Fredricks Cycle Supply Company at 916 Broadway for a few while, but by 1963 it was just Atlas all by itself again.
Bicycle Bill's involvement with Atlas seemed to start around 1965, and he even lived at that same address for a while. When he opened the Lorain Schwinn Center on Oberlin Avenue in the early 1970s, Atlas was a sister store. (See ad below.)
|1972 Lorain Phone Book ad|
I'm not sure why the sign is upside-down. But the recently redone sidewalk on that side of E. 28th Street looks real nice.