Super Mirage was a everyman's sports/touring bike, good for commuting or leisure rides, not particularly suited to either racing or long-distance touring. It was basically 2-3 up from the bottom of the line with Motobecane's premier racing and touring models having some nicer equipment and fancier tubing/lugwork.

Depending on the year of your Super Mirage, it is likely made of either Vitus or 2030 steel tubing, if it's 2030 it might have cottered cranks (which are a pain).

Post a photo or some details and we'd be happy to give you some additional info.