[CR] Demultiplicator, was Simplex Selematic 5 - What is it?

(Example: Framebuilders:Richard Moon)

Date: Wed, 17 Jun 2009 22:06:44 -0400
From: "Harvey Sachs" <hmsachs@verizon.net>
To: <jerrymoos@sbcglobal.net>, Classic Rendezvous <classicrendezvous@bikelist.org>
Subject: [CR] Demultiplicator, was Simplex Selematic 5 - What is it?


Jerry Moos, in full humor, wrote about the horrid-appearing Selematic 5: This is way kool. So is it compatible with that other great Simplex mystery the Demutiplicator? This is even better than the Suntour RD with the three jockey wheels. Campy (and Shimano) are so damn boring and predictable. Vive la France. ++++++++++++++++++++++ I'd like to politely take exception. The Demultiplicator had a reason for its existence, and many of us have bikes for which it would be helpful. The '50s Cyclo- and Simplex-type "plunger" derailleurs took up a lot of chain, and came with DT shift levers that were typically 25 - 30 mm in effective diameter. In the early 60s, parallelogram derailleurs took over, but needed < 20 mm. barrels. The demultiplicator allowed you to adapt your custom bike and have reasonably spaced shifts when using your old (but beautiful) DT lever with your new Simplex, Cyclo, Campy, or Huret rear derailleur, because it reduces cable pull. I don't know if it was cheaper than a new lever, but it did have a rationale. I have one on my 70s Hetchins, where it nicely serves to space out the shifts. That bike has a Shimano Crane shifted by Shimano counter-spring bar-end shifters, which are fairly large diameter themselves. Besides, it's sort of eye candy. :-)

harvey sachs
mcLean va.