My ~75 motobecane came stock with 27" rims, I switched to 700c because I didnt really know the difference but I gotta say I like the new rims better, could be my small frame though.

(anyone know good way to get a year on an old frame? Ive got original paint and components, it was exactly equiped as a few '75s I looked up but I am working under the assumption they stuck with the same groupset for their entry level touring bike [Mirage] for more than 1 year)