Are Motobecane bike frames butted ?
Specifically Fantum29, Fantum 29 pro, 700HT, Winsdor Cliff 4900
The Windsor Cliff 4900 says it is
The Motobecanes do not say if they are but the three main tubes probably are. Owners of these bikes can tap the tubes with their fingernails to test for butting. The "ring" will be higher pitched on the thinner tubes and more of a "thud" at the thick sections. Maybe they can give you an answer...or you could always write Mike at BikesDirect