I believe that the father raced on the velodrome in Coney Island prior to opening his shop. I grew up in the Ave U neighborhood and, (unsubstantiated) rumor had it, if you bought a nice bike from Mangano's it would disappear in a few days and end up back on their sales floor.
I don't make this stuff up, I just repeat what I heard as a kid.
FYI
Michael Haddad
Brooklyn, NY USA