Originally Posted by
kylecycler
Sven Cycles in the UK build a Berceau-style mixte like the Follis. It gives a lower step-over than if the stays were straight, right enough, and I guess the way they're curved twice enables them to attach to the seat tube higher up than if they just had one curve, if you see what I mean, and the higher up they attach, the stiffer / less noodly the frame will be. I think it's the most elegant solution of the lot, although it only gives a slightly lower step-over than straight stays. The curves of the stays are more flowing on the Sven than the Follis, but me not being a framebuilder I wouldn't know how hard it would be to do - I guess you'd need two different tube benders/formers? Can't imagine it would be easy, though, so good luck!
For a large radius bend, using a roller bender is probably required. Although I have seen people use a plywood form. The Follis could be done with something like a Diacro.
Dual diagonal frames are generally considered to be fairly noodly, no matter how they are routed. That's why higher performance step through bikes use a single top tube. If it were to be used for touring, that might matter. Otherwise, I can't imagine it would.
Originally Posted by
kylecycler
The stays on the Muse Cycles Mixte are reminiscent of those on the old Deutsche Post bikes, although that was one of the wackiest frame configurations you'll ever see (but wonderful!).
That Deutsche posit bike is pretty neat, a lot of stuff going on there. Probably would be electric nowadays.