SunTour Cyclone Mark II GT - Cable Anchor Bolt
11-10-22, 06:57 AM
#1
Wheelman
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SunTour Cyclone Mark II GT - Cable Anchor Bolt
Hiya Folks,
I just bought a cheap SunTour Cyclone Mark II GT RD on Ebay, it was cheap because it is missing the cable anchor bolt.
Luckily I already use this RD so I figured I could copy the anchor bolt I've already got.
Had a look on here and nobody gives details of how to make one so I figured somebody might find this useful.
Here's the original:
The easy way to get the bolt out/in is to push the cage to the large cog position and jam a small piece of wood (10mm x 6mm works) between the H screw and the part of the cage it stops against.
You can then get the bolt out using tweezers.
Here's the dimensions I measured:
From that I figure I can make the bolt using an M5 x 10mm stainless steel bolt with some careful drilling and filing.
The nut is a bit harder to replace.
Search for 'barrel nut' or 'sleeve nut' and you will find they are made for furniture, but there's an issue.
All the stainless steel versions I could find have a 6mm shaft, if you want 8mm you have to go zinc plated iron.
The concern is that the 6mm shaft will put too much pressure on the derailleur body next to the hole the bolt goes through.
They all have a head that's larger: 10mm for steel or 13mm for iron, so they will need to be filed down since the hole in the derailleur
body is about 8.2mm.
I'm going to try the M5 x 8mm stainless steel barrel nut (on Amazon):
Now I just have to wait for the post to arrive (from China).
I'll update this when I've made the parts.
Edit: Backup plan for the nut is to buy some 8mm stainless steel bar and tap it, then file a hexagon.
Update: Bolt completed https://www.bikeforums.net/22707041-post6.html
Update: Nut completed https://www.bikeforums.net/22716949-post14.html
I just bought a cheap SunTour Cyclone Mark II GT RD on Ebay, it was cheap because it is missing the cable anchor bolt.
Luckily I already use this RD so I figured I could copy the anchor bolt I've already got.
Had a look on here and nobody gives details of how to make one so I figured somebody might find this useful.
Here's the original:
The easy way to get the bolt out/in is to push the cage to the large cog position and jam a small piece of wood (10mm x 6mm works) between the H screw and the part of the cage it stops against.
You can then get the bolt out using tweezers.
Here's the dimensions I measured:
From that I figure I can make the bolt using an M5 x 10mm stainless steel bolt with some careful drilling and filing.
The nut is a bit harder to replace.
Search for 'barrel nut' or 'sleeve nut' and you will find they are made for furniture, but there's an issue.
All the stainless steel versions I could find have a 6mm shaft, if you want 8mm you have to go zinc plated iron.
The concern is that the 6mm shaft will put too much pressure on the derailleur body next to the hole the bolt goes through.
They all have a head that's larger: 10mm for steel or 13mm for iron, so they will need to be filed down since the hole in the derailleur
body is about 8.2mm.
I'm going to try the M5 x 8mm stainless steel barrel nut (on Amazon):
Now I just have to wait for the post to arrive (from China).
I'll update this when I've made the parts.
Edit: Backup plan for the nut is to buy some 8mm stainless steel bar and tap it, then file a hexagon.
Update: Bolt completed https://www.bikeforums.net/22707041-post6.html
Update: Nut completed https://www.bikeforums.net/22716949-post14.html
Last edited by Aardwolf; 11-21-22 at 09:05 AM. Reason: Nut completed
11-10-22, 07:17 AM
#2
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Drilling the cable's through hole will interesting. I'd file a flat spot on the bolt to start the drilling.
Good excuse to buy a milling machine! 😉
Good excuse to buy a milling machine! 😉
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11-10-22, 07:20 AM
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Here in the US, I'd head to a co op and dig through their broken derailleur bin. Lots of Suntour RDs from that era shared that design.
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11-10-22, 07:40 AM
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Wheelman
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I made some cable hangers for a green house by drilling through M5 bolts a few years back.
Luckily I've got a selection of drills from 1mm - 2.5mm.
As I typed that the bolts came through the letter box.
11-10-22, 07:46 AM
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I think I made something like that out of a brake caliper cable bolt one time.
11-10-22, 02:48 PM
#6
Wheelman
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Bolt completed.
Fairly straightforward, it even works.
Fairly straightforward, it even works.
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11-10-22, 04:08 PM
#9
Wheelman
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Cheers,
A clue for anybody else doing this: Put the 2mm drill bit back in the hole so you are sure of the alignment while filing etc.
A clue for anybody else doing this: Put the 2mm drill bit back in the hole so you are sure of the alignment while filing etc.
11-10-22, 08:04 PM
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Impressive, but can you make an entire derailleur out of coconuts like the Professor on Gilligan's Island?
11-10-22, 08:52 PM
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Love it when someone figures out a DIY fix and brings back a vintage part back to life!
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If someone tells you that you have enough bicycles and you don't need any more, stop talking to them. You don't need that kind of negativity in your life.
If someone tells you that you have enough bicycles and you don't need any more, stop talking to them. You don't need that kind of negativity in your life.
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11-11-22, 02:24 AM
#12
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Cost so far is 27p (32 cents) for one bolt.
I call that a bargain
I call that a bargain
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11-21-22, 09:03 AM
#14
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Post from China arrived
While I was waiting I tried to make a nut from 8mm stainless steel rod.
It was a royal PITA because stainless steel is really hard, gave up in the end.
Then I found an 8mm brass bushing in my parts bin and tapped that at M5
The barrel nuts are exactly as described except they take a 3mm hex key which I hadn't spotted.
Had to file the head down to 8mm diameter.
Left to right: 8mm brass widget, barrel nut modified, barrel nut original
And here they are in use (with the new bolt):
So far I'm preferring the brass version: it's 8mm diameter all the way down so it spreads the load better, and the barrel nut isn't 4mm hex so I would need an extra tool anyway.
While I was waiting I tried to make a nut from 8mm stainless steel rod.
It was a royal PITA because stainless steel is really hard, gave up in the end.
Then I found an 8mm brass bushing in my parts bin and tapped that at M5
The barrel nuts are exactly as described except they take a 3mm hex key which I hadn't spotted.
Had to file the head down to 8mm diameter.
Left to right: 8mm brass widget, barrel nut modified, barrel nut original
And here they are in use (with the new bolt):
So far I'm preferring the brass version: it's 8mm diameter all the way down so it spreads the load better, and the barrel nut isn't 4mm hex so I would need an extra tool anyway.
