Serial number Y79 0505511. I’ve tried to match it with the information but can’t seem to find a match. Dose anybody have a idea what model and year? I think it’s a 1979 because of the sn any help would be appreciated. Sr handlebars, sun tour DT shifters, Super Maxy crank, sun tour cyclone DR, top run Petals and the bike is black. I’m going to take pics and post later. Thanks!