I have a Synchron brake and it looks like Shimano modified this design for there dual pivot brakes. It was a great idea that failed until the great Shimano design/marketing machine took it on. As a kid my friend had a 1972 Columbia(a true fallen classic name) with sidepull brakes by either Dia compe or Altenberger which had a red anodized lever between the arms. Does anyone remember this design and how it worked?