Are the bodies identical for the first generation Cyclone and the Cyclone GT?
Put another way:
Will a Cyclone GT cage bolt onto a Cyclone body?

Thanks,
Brent

Yes, the GT and short cage are interchangeable.

Many thanks!
Brent

Yes. But note that for both there were at least two versions: one with a short/shallow mounting bolt, and one with long/deep. Not sure which came first - my guess is the shorter is later, which would allow for more reach for 6+ gear clusters. I suppose a date code investigation could deduce that.

Short bolt:





Long bolt:

That's so pretty. Wow!

Thanks for the clarification!

Brent

They really are.

And astoundingly light.

The short cage Cyclone II on my UO-8 (with SunTour ratchet barcons, narrow ("ultra") 6-speed 13-15-17-20-23-26, and 3-tooth half-step chainrings) is the best-shifting derailleur I have ever owned.

Agreed. I was so surprised the first time I held one.

My fave RD, easy.

Out of curiosity, was this 1st-gen Cyclone the derailleur Suntour dropped on the world to debut the slant parallelogram? Or was there something else? Because as game-changers go, this mech would've been stunning on many different levels.

Before the Cyclones the "V" series of derailleurs, also slant parallelogram, were extremely popular. Those are the first ones I remember but I believe there were a couple Suntour slant parallelogram steel derailleurs that preceded the "V" series.
Brent

This website might have your answer.

*This* website? Or another website that was not quite linked to?

As I understand the Gran Prix was the first Suntour Slant Parallelogram rear derailleur- at least according to Disraeli Gears:

SunTour Gran-Prix derailleur






EDIT- not a lot of pix of the Maeda Grand Prix in use- I suppose it's an old unit that was primarily for the Japanese/Asian market...

Since this thread is still on page 1 I'll ask another Cyclone question:
Does anyone know of a good source for a replacement cable clamp bolt and nut? I'm pretty sure that, with some filing and threading, I could cobble one together using a pinch bolt from a center-pull brake yoke or from another derailleur but it would be nice to find the genuine article.
Brent

My bad, forgot to post the link.

I made one from a Dia Compe brake cable bolt/nut. You just have to grind/file down one side of the head.

Agreed about the shifting. I have three (I think) bikes with the GT version and their shifting is unbelievably precise.

I have also experienced the cage spring breaking three times. Unfortunately the spring is not interchangeable with the V series. Last year I looked into have a batch of spring made. Had there been enough interest I would have pulled the trigger on it, but I got all of maybe two responses, one after I'd already given up on the project. At leat the GT and short cage versions use the same spring.

Keep in mind that on the GT version, the bolt that the cage pivots around is also the axle for the jockey pulley.

I rebuilt my GT when I replaced the pulleys, then the spring broke shortly thereafter when I shipped it to Europe with the rest of my stuff... The modern Shimano replacement is nice, but that derailleur had so much class.

I loved the fact that when I raced in the '70s and everyone who was anybody raced full Campy that my Fuji Pro had derailleurs that were considerably lighter AND shifted far better!

Ben

This is an important question. Older (earlier?) '70s Cyclone RDs had a smaller diameter bolt (and thus hole that the bolt slotted through) compared to later ones (late '70s, early '80s or so) whose diameter was bumped up slightly. They are not interchangeable, as I have found.

Brent, I recently did a short for long cage swap. I don't remember precisely what the hurdle was, but it wasn't quite as easy as changing the short cage for the long cage. Give me until tomorrow afternoon and I'll try to give you some more details. If I recall correctly, the mounting bolt that goes through the RD body and threads into the cage was slightly different (not the mounting bolt that goes into the hanger, but the other pivot bolt). That bolt threads into another section, which then threads into the cage. I believe I had to swap both the cage and the other pivot mounting bolt.

I went from this:


To this:


Btw, recognize that FW?

P.s. Sidenote: Another difference I noticed is that the b-adjustment screw also went through some subtle changes as this derailleur evolved. The b-adjustment screw on the GT version (from which I grafted the long cage) is slightly wider at the head and does not clear the RD body of the short-cage body enough to provide the same range of adjustment.

[MENTION=175208]gaucho777[/MENTION] is correct. The pivot bolt is different between the short and long cage versions, and it mounts to the cage differently. On the GT it goes through the guide pulley then screws into the cage, and a flat locknut with notches then screws on from the inside to lock it in place. Removing that locknut requires a tool with tiny prongs. That's why removing the pulley is harder on the GT version. On the short cage version the blot attaches directly to the cage and the pulley is held by a separate short bolt as per most other RDs. On at least one of the Cyclones, and perhaps I am remembering the Mk2 instead but it might be the short cage 1st gen, the pivot bolt doesn't screw into the cage, Rather it has flats on the shaft which fit into a flat-sided hole in the cage, the flats rather than threads keeping the cage from turning on the shaft.

So you should be able to swap cages but it must include the pivot bolt.

I was wondering when that tool was going to get mentioned...

I've said it before, I'll say it again... that bike is hot.

I use small needle nosed pliers, set to the right spacing, and in a bench vise. Works well.