Originally Posted by Sixty Fiver

I love the Cyclone GT Mk1 and the Mk2 is pretty much perfect mechanically although if given the choice between a Mk2 and a VX I would take the VX as it looks 10 times better, is more robust, and only weighs a few more grams (if you are counting) and have always loved their performance.

The earlier Suntour GT models are also nice but Suntour really hit their zenith with the Vx and Cyclone series... there is not a friction derailleur that will shift better.

The Cyclone Mk1 is one of the lightest derailleurs ever made and the GT model is lighter than most modern long cage derailleurs... only snobbery kept people from using these instead of Campagnolo on racing bikes and if you are looking for the ulitimate light weight touring derailleur with massive capacity this is it.

Huret Duopars work beautifully and have some nice features like an adjustable pivot but they are based on earlier slant parallelogram designs and are not as long lived as one would like them to be.