> The Cinelli bivalent required a special freewheel that was made by Regina.
> The body was splined instead of threaded. Good luck in finding one.
> John Alden
I asked the Pres. of Regina back in 1989 at the Milan bike trade show about the availablity of the splined bivalent body and he said they were gone years ago! The bivalent cogs (they're Oro cogs) are very easy to find, so no worries there.
There are many more hubs (front and the back are one and the same) than there are splined bodies to make them work :(
Incidently, there were two versions. The original version was of three-piece construction, with the steel center barrel milled for bearing races and pressed-on aluminum alloy flanges with a very small thread-on spline ring. The later version was of all aluminum construction with pressed in bearing races and a much beefier thread-on spline cap (obviously an improved design over the earlier three-piece model).
Pluses: support vehicle in race only needs one style wheel (front/back), you can easily exhange front position for back position to even out tire wear, "back wheel" is dishless.
Minuses: everyone on team needs to be running same bivalent system, "front wheel" strength compromised by narrow flange spacing, "rear wheel" strength compromised by narrow flange spacing, can't run less spokes and lighter rim on "front wheel", and spline interface between hub and freewheel body wears to poor fit.
Not an everyday user, but my '60 Cinelli SC with the bivalents is fun to ride and will certainly be enjoyed by "someone" well into the next century and beyond I'm sure.
Chuck Schmidt South Pasadena, California http://www.velo-retro.com (NEW list of vint. reprints and T-shirts)