Montmartre is an area of Paris known for its cafes and artist's studios. The Montmartre bar is a very traditional French city bar.
Like most traditional French bars, the Montmartre bar is narrow, 42cm center-to-center. The streets of Montmartre are also narrow and it wouldn't do to knock over a drink at a cafe table or snag a Citroen's rear view mirror; that could happen with the wide Harley-style bars so popular on this side of the Pond. Besides, a proper low trail city bike has geometry that allows it to hold a straight line with almost no input, yet turn with only the gentlest touch. We are piloting a fine bicycle, not a tractor!
The rise on the Montmartre bar is about 6cm; reach is about 18cm. Grip area is around 12cm. The stem clamp diameter is 25.4mm and the bars are bulged, rather than sleeved, so they will not squeak.
These bars are available in two tubing diameters, 23.8mm road sized and 22.2mm mountain-bike- sized (clamp area is 25.4mm on both):
22.2mm (MTB-size) bars accept MTB brake levers and clamp-on shifters. They do not work with bar-end shifters. The only inverse levers that work are Dia Compe levers in the 22.2mm size.
23.8mm (road-size) bars accept standard inverse brake levers, standard bar-end shifters, and 23.8mm city brake levers. In short, anything made for road bars fits. They do not accept MTB levers or shifters.