Quote:
A style of lady's frame in which the "top tube" consists of a pair of small diameter tubes running more-or-less straight from the upper head lug, past the seat tube, and on to the rear fork ends. A mixte frame thus has 3 sets of rear stays, instead of the usual two. A variant on the mixte uses a single, full sized top tube running from the upper head tube to the seat tube, but retains the middle set of stays. A lady's type bike that lacks the middle pair of stays is not a mixte.
Mixte frames are stronger than conventional lady's frames, particularly in resisting the tendency of the seat tube to get pushed backward in the middle when ridden by a heavy rider
In French, "mixte" would be pronounced "MEExt", but normal U.S. bicycle industry pronunciation is "MIX-ty".
I think the other step-through frames are just "ladies' bikes." I have seen photographs of bikes that looked like mixtes from early in the 20th century, but I don't think they were common or necessarily aimed at women then. I saw one in a gallery of old Dutch bikes, as well, but a lot of those bikes had weird, non-diamond frames so I am not sure if they were commonly made (or even how old they were). I have also seen one for sale on eBay that was purported to be custom built from the 50s, and the seller wanted a gajillion dollars for it, but I have no idea if it was legit or not.