[cross-posted from Mechanics when I realized I'm more likely to get an answer here.]

I was writing up the section on Roller cam brakes in Wikipedia and while looking for a good picture I ran across a thing called a "toggle cam" brake. I've never seen one - and Sheldon makes no mention - but from the few pics it looks like a one-sided roller cam design with a slaved arm (how?).

Anyone know how these operate? How common they were? Good or bad?


I also found a reference to a "sabre cam" design. I believe the front brake on this bike (click on the thumb of the front brake for a pic) is a sabre cam. Anyone know anything about them?