The Polyvalent is an urban bike that's also capable of being used for cyclo-touring, brevets, and club rides. Polyvalent is French for "general purpose."
Wheel size is 650b, which we feel is really the best choice for a comfortable ride on bumpy city streets or rough country roads. Maximum tire size with fenders is around 44mm and around 55mm without, but the frame handles best with a tire around 38mm wide.
The rear dropouts are short horizontal dropouts to allow internal hubs and single speed wheels to be used without the need for a chain tensioner. Longer dropouts would make wheel removal difficult on a fendered bike. Rear spacing is 132.5mm, so both 130mm and 135mm rear hubs fit.
There's more here.