Cyclone MK II RD - get spring back into place
 

Need help and tricks how to reinsert the RD tension spring.
I took it out for come cleaning and now I struggle to get it back in place.

Any advice?

this video might be useful to you...

If I had to guess, I would guess that you haven't removed the little screw that keeps the pulley cage from rotating too far clockwise.... but pictures would help clarify what you specific problem is.


Steve in Peoria

I've never had the guts to take one apart-now I do!

Thanks!

Glad to be of service. :)

With the Cyclone GT, the only hard part is getting the nut off of the back of the upper pulley. I've seen pictures of the official SunTour tool. RJ, the fellow who made the video, sort of glosses over the removal and reinstallation of this nut (he doesn't have a proper tool for it).

My dad, back in the day, made one for me from a bushing, which I still have. It might be easier to hack up a cheap screwdriver??

The rest of the overhaul is not bad, and similar to most other derailleurs of the era.


Steve in Peoria

Any chance we could see a picture of either the "official" tool or the homemade one?

here are a few quick shots of the one my dad made....

https://c1.staticflickr.com/9/8616/2...fdcc71_c_d.jpg

https://c1.staticflickr.com/9/8727/2...3f40ff_c_d.jpg

https://c1.staticflickr.com/9/8114/2...fa241c_c_d.jpg

The tool is probably a bit more sophisticated than is essential... my dad was working as a machinist at the time. :)

Steve in Peoria

Thank you for sharing this informative video. I noticed the different slots on the bolt that the spring slots into. Any idea if these are meant to be used to adjust/change the spring tension?

yes... but only at the time of manufacture (my opinion, of course).

The shaft with the slots for the spring is threaded, and of course, threads into the pulley cage. I would guess that when the hole in the pulley cage is tapped, and when the die is used to cut the threads on the shaft, the rotational position of the threads aren't controlled. As such, the position of the spring slots relative to the pulley cage would be random. This would require some way to set the spring tension during assembly. (again, this is my guess).


Steve in Peoria

Thanks so much. Very cool. Looks like a small SunTour freewheel tool.

Thank you very much for the video.
http://imgur.com/a/E5Tvxhttp://imgur.com/YTG0MEp
http://i.imgur.com/YTG0MEp.jpg

The issue I have is that the spring is out of its recess like in this picture (lifted from the interweb).
I cannot get the spring coiled up tight enough to reinsert into the recess.

I would try to "hook" the end in, then using a pair of needle nose vise grips, wind it to collapse and insert.
I think this is a three had job, I would secure the body to a bench.

Do you have the stop screw removed from the cage? The derailleur goes together first, then tension the spring by winding the cage counterclockwise one rotation. Holding the derailleur with one hand reinstall the stop screw.

Thank you Brian3069.
No - the stop screw is in place.
How does the unwinding the cage help me get the spring into the recess?

Sorry, I misunderstood the issue you are having.

When you disassembled, did you remove the stop screw and de-tension the cage before you removed the cage? You may need to reinstall the cage without the stop screw, then rotate the cage to tension it, then reinstall the stop screw.

I may be wrong, but it looks like tension is achieved by rotating the spring counterclockwise (as pictured there) so that it flexes into the stop and coils into itself. Just a guess -- please shoot down this idea if it is cuckoo.

I have taken apart a couple of derailleurs, but have yet to see a flat spring like this. I also have a Cyclone MKII that needs an overhaul, so I will be curious to see the result here.

EDIT: Reading Velocivixen's explanation below makes total sense to me...

Just curious. Did this derailleur have spring tension prior to disassembly? I'm wondering if the other end of the spring is supposed to have a "hook" shaped end to fit into the slot you're referring to?

EDIT: I believe that what brian3069 said is correct. When you put the derailleur pulley section onto where that spring is, then then the pulley assembly counter clockwise that bare spring you see will sort of "unravel" if you will and the angled piece in the center will find its way into the slot. Hope this helps.

fwiw, I'm working on photos of disassembling one of these GT Mk IIs.....


Steve in Peoria (should be doing something more useful... :) )

okay.... I took a ton of photos, so I'm going to post them a handful at a time... along with very brief descriptions. Feel free to ask questions.


4765 start with the derailleur
https://c1.staticflickr.com/9/8055/2...18ce71_c_d.jpg

4766 rotate the cage counter-clockwise
https://c2.staticflickr.com/8/7737/2...235d17_c_d.jpg

4767 remove the stop screw
https://c1.staticflickr.com/9/8835/2...b47f49_c_d.jpg

4769 allow the cage to rotate clockwise
https://c1.staticflickr.com/9/8605/2...df90c0_c_d.jpg

4770 remove the allen nut
https://c1.staticflickr.com/9/8254/2...8a3a4c_c_d.jpg


Steve in Peoria

sequence of photos, part 2:



4771 slide the cage out the back. Note: there is a little wedge that is in the slot in the shaft and it will pop out when the spring comes out of the slot in the shaft. Don't lose the little wedge! You can see the wedge in a later photo.
https://c1.staticflickr.com/9/8033/2...ddfb4d_c_d.jpg

4772 backside of the derailleur body
https://c1.staticflickr.com/9/8741/2...b1c5cf_c_d.jpg

4773 back of the body and cage. Note the little wedge in the lower right of the photo. This is what was in the slot of the shaft, and held the spring in place.
https://c2.staticflickr.com/8/7471/2...65713b_c_d.jpg

4774 remove the nut from the upper pulley
https://c1.staticflickr.com/9/8607/2...511a5d_b_d.jpg

4775 remove the shaft from the cage
https://c1.staticflickr.com/9/8687/2...46d2ec_c_d.jpg


Steve in Peoria

sequence of photos, part 3:


4776 note the hex flats on the shaft that mate with the cage
https://c1.staticflickr.com/9/8863/2...6976e0_c_d.jpg

4777 the cage and shaft
https://c1.staticflickr.com/9/8360/2...e20800_c_d.jpg

4778 the hex hole in the cage
https://c2.staticflickr.com/8/7569/2...2115a3_c_d.jpg

4779 the cage and the shaft
https://c1.staticflickr.com/9/8661/2...bda73a_c_d.jpg

4780 the shaft and the spring cover
https://c1.staticflickr.com/9/8498/2...5201fb_c_d.jpg


Steve in Peoria

and the last sequence of photos....


4781 reassembling the shaft and cage.
note: I didn't show that I added a little grease between the plastic sleeve on the shaft and the spring cover. This rotating joint supports the inboard side of the shaft.
https://c1.staticflickr.com/9/8864/2...477992_c_d.jpg

4782 inserting the cage assembly into the derailleur body
https://c1.staticflickr.com/9/8741/2...578865_c_d.jpg

4783 put the wedge into the slot, and then the allen nut onto the shaft.
https://c1.staticflickr.com/9/8403/2...671d2d_c_d.jpg

4784 rotate the cage counter-clockwise
https://c1.staticflickr.com/9/8676/2...1aebc2_c_d.jpg

4785 install the stop screw
https://c1.staticflickr.com/9/8812/2...6c8328_c_d.jpg

4786 this is a view from above, showing the stop screw hitting the stop.
https://c1.staticflickr.com/9/8631/2...d62b62_c_d.jpg

4787 another view, showing the stop screw hitting the stop.
https://c1.staticflickr.com/9/8786/2...0f3fdb_c_d.jpg

4788 the reassembled derailleur
https://c1.staticflickr.com/9/8857/2...e2f104_c_d.jpg



Steve in Peoria

Holy Derailleur

This thread is taking helpfulness to a totally new level.
You guys rock.

Plan for tonight:
Pizza & Beer, followed by some quality time with a Suntour derailleur while looking at the photos of steelbikeguy disassembling the best RD ever made.

grazie mille!

or, since this is SunTour,

Doumo arigatou!

glad to help.... besides, it was a learning experience for me. I've taken the 1st generation Cyclone GT's apart many times, but don't think I've ever taken a 2nd generation (i.e. Mark II) apart before. I generally prefer the 1st generation models, so wasn't surprised that this poor Mark II was hiding at the bottom of my box of derailleurs.

I like the fact that the shaft doesn't screw into the cage, but am not as fond of the use of the plastic as the bushing bearing for the shaft. Perhaps it tolerates neglect better??

Steve in Peoria

Great thread here.

For posterity, I thought I might add a photo of the 'official' tool:

Attachment 534787

Attachment 534788