Switching long and short cages on the first generation Cyclone has been mentioned several times on this forum. I finally had a need to do so on a Raleigh Pro that I'm building for the California Eroica this year. I had a short cage black edition Cyclone that I wanted to outfit with the long cage. I recorded the steps for posterity and for those who might be encouraged by a few photos to attempt this rather simple procedure.


Start by unscrewing the limiting screws on both cages and allow the cages to unwind their spring tension.



I disassembled the long cage derailleur first. The bolt that attaches the cage to the body also holds the two sides of the cage together, sandwiching the upper pulley between the two cage plates. There is probably a special tool for removing the slotted nut but my snap ring pliers worked fine for the job.



Here is the backside of the short cage derailleur for comparison. Notice that the cage is attached differently. The attaching bolt threads directly into the front cage plate. The pulley and rear cage plate are in the way of seeing where it attaches but you will see that in the disassembled view a little later.



Once you have removed the nut from the back of the cage you can unscrew the fixing bolt as shown.



The fixing bolt will now lift out of the barrel. With luck the spring will come with it, but if it seems stuck in place you can easily push it out of the little hole at the back of the barrel with a stout wire.





On to the short cage removal. Since there is no nut to remove from the cage you skip that step. Holding the cage in your hand or a vise you can again use your allen wrench to unscrew the bolt from the barrel but, surprise, this time it's not a bolt it's a cap under which lurks the real bolt and the spring. I'll bet there is a special tool for removing this bolt/spring retainer but I found that my Shimano chainring bolt tool worked just fine.



Here you see both derailleurs disassembled. I disassembled the short cage before removing it but that step turned out to be unnecessary.



Move the cages and all of the hardware from one body to the other. Reassembly is the opposite of disassembly, with a little grease thrown in for good measure.



I'm sure other members more experienced and knowledgeable than I can add some pointers here.
My thanks to jeirvine for the long cage derailleur.

Brent

FWIW Suntour made a special tool for the nut on the GT models.

Nice write up!

There sure is a special tool:

Wow, yours is a really nice example! Mine is pretty utilitarian in comparison.

Nice instructable!
Only thing I'd add is that you have a choice of where to slot the spring into the castellated bolt (#20). Do this after first attaching the bolt to the cage. You can get more or less spring tension, depending. Too much tension can result in a snapped spring.

Oh, and you can also use a Vx-S or Vx-T cage for a medium cage Cyclone.

This is cool; I didn't know you could do this.

Yes, the TA-270:

Thanks for the well documented story!

I've pulled my Cyclones apart for general maintenance and to replace a broken spring. As noted, there are a couple of challenges in the process.
My solution to unthreading the axle/bolt from the pulley cage plate is to slide the cage/bolt assembly back out of the derailleur housing, which exposes the bolt enough to just grab it with a vise-grips (locking pliers). If nothing else, it provides a bit more leverage than the chainring spanner that you used. There are probably other ways of doing it too.

A quick shot of my disassembled Cyclone, along with the broken spring.



This is the second SunTour spring I've had break. The other is a somewhat similar coil spring on the XCD Pro cantilever brake. It also broke at the bend where the spring was supposed to engage with a locating hole.

Steve in Peoria

I did this with a MKII Cyclone, using the cage from a ratty GT and the rest from a nice short cage to make a nicer looking GT. A quick note, though, that the generations cannot be mixed. The knuckle/pivot where the cage affixes is narrower on the MKII than the first gen.

Nice write up! I could have used this a few days back when I was scratching my head with a cyclone.

Big question for me: How do you setup and judge spring tension when you reassemble? I want it to feel snappy, but how much is too much?

I shoot for the cage to rest at about 11 o'clock, with the stop screw removed, but with the bolt and cage tight:



And here's a Cyclone-T, using a mid-cage from a Vx. You can swap in that, or a Vx-S cage, without needing the longer castellated bolt from a Cyclone GT. I haven't tested this, but I think it could be just the ticket on the right build:

The cage on the elusive Suntour Superbe long cage FD-5800 and the cage on the Suntour XC are the same. The only difference is where the hole for the stop screw is drilled. So, you can buy a XC for cheap and make yourself a Surperbe long cage RD from a RD-5300. You'll need to drill/tap a new hole then move the stop screw.

VeloBase.com - Component: SunTour Superbe II (long-cage friction)

VeloBase.com - Component: SunTour XC