Originally Posted by
The Golden Boy
......
The Cyclone... The Cyclone was one of the lightest, and best shifting derailleurs both of its day and to this very day. They're great and reliable and it's easy to get the chain off, and it's beautiful to look at. I used both a "first generation" and an MII on my 720 for a while- they just felt much more "dainty" than other touring derailleurs. I have not heard a whole bunch of 'Cyclone derailleurs' giving out stories- but I have heard of it. You'd probably be absolutely fine- and it'll be period correct and it'll shift flawlessly and it'll be dominant...
......
is there a sticky thread on "broken derailleurs"?
well, I'm a fan of the Cyclone GT and have used them since they were new. Still, I feel compelled to mention that I've had two where the lower pivot spring has broken. One broke while the bike was in the work stand, which is perfect timing!
The other broke 3 miles into a bike ride. The chain managed to jump out of the pulleys and jam between the hub flange and freewheel. Somehow the chain managed to also hang up in the front derailleur and cause significant damage.
Some photos, just because...
the disassembled derailleur, with a good spring shown next to the broken spring. The bent end that fits into the hole in the derailleur pivot housing is what broke.
and a close-up of the break
I created a thread about this on the I-Bob group, and was surprised at how many folks have suffered various types of failures. There was no obvious problem with these lower pivot springs, based on the discussion at that time.
By chance, my touring bike has SunTour canti brakes, which use springs with a similar right-hand bend. I had one of these break in the same way, but just that one failure. No indication of a design or manufacturing problem.
There have been some reports of broken lower pivot springs on the Cyclone GT Mark II too, even though the design is completely different. There is a general rule that says "everything eventually breaks", which seems applicable for 40 year old derailleurs.
Steve in Peoria
(I had to carry the poor bike for the 3 mile walk home)