Check the serial number here:http://www.vintagecannondale.com/ I'd agree with it being a mid - late 80's SR model that was painted and generic decals applied, it isn't any type of Denali or Schwinn. the cable guides on the top tube are the plastic models that are next impossible to find, if needed, the rear drop is the Cannondale SR type from that era and the tubes are the size and profile that Cannondale used then. It has a thread-less stem adapter and stem installed in the threaded fork and head set, not original, that would have been threaded with a quill stem. Not sure how they adapted the brifter system, original was down tube shifters and, as said the aluminum rear triangles don't take to a cold setting so it is most likely a six or seven speed rear. Looks like a Biopace chain ring on front as well.

Bill