Tightned the sides - tightens the clamp. Turned the bike upside down and worked the shifter with wheels going - keeps coming loose. No bump under the tube - smooth all the way down. Not much room between the clamp and the tube re: wrapping something around the tube. Adding a shim (soda can lid / small piece of rubber under one side of the band) might work.
Are these shifters worth the effort to make work? Are there other shifters (not expensive) that do the job better?
What about adding a brazeon? Is that hard to do?
Googling for Suntour Cyclone endless band shifters -
http://www.sheldonbrown.com/org/brown/index.html
In 1984, I fell in love with the Shimano Dura-Ace SIS shift levers. The old SunTour units slipped all the time and had never been satisfactory. I wasn't convinced about indexing, but loved the feel of the Shimano levers, so I bought a pair, originally intending to use them in friction mode.
Once I had the indexing levers, however, I had to try to get indexing to work. I drilled out the housing stop of the SunTour Cyclone rear derailer, and tapped it to receive an adjusting barrel, in the hope that I might luck out and have a workable shifting system. Mirable dictu, it worked!
The short cage Cyclone can't handle the take up if I try to use the 28 tooth ring with any of the smaller rear sprockets, but I never have any occasion to use those gears anyway, so it works fine for me.
Most recently, further in the spirit of breaking the rules, I installed a set of Campagnolo Veloce 10-speed Ergo shifter...still with the 30 year old Cyclone and the 6-speed Regina Oro freewheel...and that works too!
Even Sheldon Brown had pblms with his shifters!! So sad to recently learn of his passing away. Very grateful to his words of inspiration and knowledge to keep moving forward bicycling and with life.