Go Back  Bike Forums > Bike Forums > Classic & Vintage
Reload this Page >

Suntour GT rear derailleur: how to assemble?

Notices
Classic & Vintage This forum is to discuss the many aspects of classic and vintage bicycles, including musclebikes, lightweights, middleweights, hi-wheelers, bone-shakers, safety bikes and much more.

Suntour GT rear derailleur: how to assemble?

Old 04-09-21, 08:01 AM
  #1  
John Nolan 
Senior Member
Thread Starter
 
Join Date: Apr 2007
Location: Ottawa, Canada
Posts: 651

Bikes: Raleigh Classic 15, 84; Miyata Ridge Runner SE, 85; Miyata 610, 86; Miyata 100M, 86; Miyata Valley Runner, 88; Miyata Triple Cross, 89; GT Karakoram, 90; Miyata Elevation 300, 91; Marinoni Touring, 95; Long Haul Trucker, 2013

Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 131 Post(s)
Liked 59 Times in 36 Posts
Suntour GT rear derailleur: how to assemble?

I'm trying to assemble this Raleigh branded Suntour GT, but I'm missing some understanding, and, maybe, some part. I picked it up at my co-op a couple of years ago, and it may not have all the original fittings. The claw didn't come with it.

I don't understand how to tighten it onto the claw and still allow it to pivot. I've never assembled a derailleur with a claw and a jam nut. I'm not clear what the jam nut is for, since integrated hangers don't seem to need one.

I've included a picture of the fittings placed in the order I've tried for assembly:
pivot bolt, then 2 thin washers, then derailleur body, then thin washer, thicker washer, then pivot bolt threaded into claw, then jam nut. It also had the tabbed washer you see above the thicker washer, but I don't understand what that's for, or where it goes. If I include it there's not that much thread left for the jam nut.

When I pulled this out of my parts bin, I thought this would be a no brainer, but I forgot who I was dealing with.



John Nolan is offline  
Old 04-09-21, 01:28 PM
  #2  
oneclick 
Senior Member
 
Join Date: Feb 2020
Posts: 1,503
Mentioned: 26 Post(s)
Tagged: 0 Thread(s)
Quoted: 556 Post(s)
Likes: 0
Liked 521 Times in 328 Posts
That tabbed washer is a wheel-axle-retaining gizmo, usually seen on front wheels; the dropout has a little rectangular hole above the axle slot, into which the tab fits, the washer section is placed on the axle inside the nut. If your wheel is loose it (is supposed to) stay(s) in.

I discard them, my nuts are tight.

(It's not part of your derailleur, it came from somewhere else.)
oneclick is offline  
Old 04-09-21, 01:34 PM
  #3  
John Nolan 
Senior Member
Thread Starter
 
Join Date: Apr 2007
Location: Ottawa, Canada
Posts: 651

Bikes: Raleigh Classic 15, 84; Miyata Ridge Runner SE, 85; Miyata 610, 86; Miyata 100M, 86; Miyata Valley Runner, 88; Miyata Triple Cross, 89; GT Karakoram, 90; Miyata Elevation 300, 91; Marinoni Touring, 95; Long Haul Trucker, 2013

Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 131 Post(s)
Liked 59 Times in 36 Posts
Originally Posted by oneclick View Post
That tabbed washer is a wheel-axle-retaining gizmo
I know I'd seen them somewhere!

So, one mystery solved.
John Nolan is offline  
Old 04-09-21, 01:36 PM
  #4  
oneclick 
Senior Member
 
Join Date: Feb 2020
Posts: 1,503
Mentioned: 26 Post(s)
Tagged: 0 Thread(s)
Quoted: 556 Post(s)
Likes: 0
Liked 521 Times in 328 Posts
Originally Posted by John Nolan View Post

I don't understand how to tighten it onto the claw and still allow it to pivot. I've never assembled a derailleur with a claw and a jam nut. I'm not clear what the jam nut is for, since integrated hangers don't seem to need one.
The integrated dropouts almost always have a slight boss where the derailleur mounts, the derailleur manufacturers (should) arrange matters so that the upper knuckle's inner face is outside the outer edge of this boss. That means the upper pivot bolt can be screwed down TIGHT and the knuckle will still pivot; no jam nut needed. Claws rarely have such a boss, so the necessary clearance for the pivot is done with a locknut on the pivot bolt - you get it just loose enough to swing, and jam it there.

(Some rear mechs have a shouldered pivot bolt and shims to get the same result.)
oneclick is offline  
Old 04-09-21, 01:55 PM
  #5  
John Nolan 
Senior Member
Thread Starter
 
Join Date: Apr 2007
Location: Ottawa, Canada
Posts: 651

Bikes: Raleigh Classic 15, 84; Miyata Ridge Runner SE, 85; Miyata 610, 86; Miyata 100M, 86; Miyata Valley Runner, 88; Miyata Triple Cross, 89; GT Karakoram, 90; Miyata Elevation 300, 91; Marinoni Touring, 95; Long Haul Trucker, 2013

Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 131 Post(s)
Liked 59 Times in 36 Posts
Thanks for that...that's what I imagined, but I can't seem to figure out how to keep the adjustment when I tighten down the jam nut.

I installed the derailleur and claw on the frame, adjusted the pivot bolt, and tried to hold the pivot bolt in place with a hex wrench while tightening the jam nut, but things still ended up too tight.
John Nolan is offline  
Old 04-09-21, 02:45 PM
  #6  
philbob57
Senior Member
 
Join Date: Jul 2013
Location: Chicago North Shore
Posts: 1,822

Bikes: frankenbike based on MKM frame

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 534 Post(s)
Liked 295 Times in 182 Posts
I thought the slant-parallelogram ders didn't need to pivot.
philbob57 is offline  
Old 04-09-21, 02:57 PM
  #7  
John Nolan 
Senior Member
Thread Starter
 
Join Date: Apr 2007
Location: Ottawa, Canada
Posts: 651

Bikes: Raleigh Classic 15, 84; Miyata Ridge Runner SE, 85; Miyata 610, 86; Miyata 100M, 86; Miyata Valley Runner, 88; Miyata Triple Cross, 89; GT Karakoram, 90; Miyata Elevation 300, 91; Marinoni Touring, 95; Long Haul Trucker, 2013

Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 131 Post(s)
Liked 59 Times in 36 Posts
Originally Posted by philbob57 View Post
I thought the slant-parallelogram ders didn't need to pivot.
Oh, that would make things easier!
John Nolan is offline  
Old 04-09-21, 03:11 PM
  #8  
Big Block
Senior Member
 
Join Date: Jan 2010
Location: Adelaide, Australia
Posts: 730
Mentioned: 31 Post(s)
Tagged: 0 Thread(s)
Quoted: 171 Post(s)
Liked 64 Times in 36 Posts
the exploded drawing
Big Block is offline  
Old 04-09-21, 03:17 PM
  #9  
John Nolan 
Senior Member
Thread Starter
 
Join Date: Apr 2007
Location: Ottawa, Canada
Posts: 651

Bikes: Raleigh Classic 15, 84; Miyata Ridge Runner SE, 85; Miyata 610, 86; Miyata 100M, 86; Miyata Valley Runner, 88; Miyata Triple Cross, 89; GT Karakoram, 90; Miyata Elevation 300, 91; Marinoni Touring, 95; Long Haul Trucker, 2013

Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 131 Post(s)
Liked 59 Times in 36 Posts
Originally Posted by Big Block View Post
Yes, I have looked at the diagram at Disraeli Gears (BTW your link doesn't work for me, i don't know why.) I didn't have exactly the same arrangement of washers, and I couldn't figure out from that picture how to adjust things.
John Nolan is offline  
Old 04-09-21, 03:20 PM
  #10  
oneclick 
Senior Member
 
Join Date: Feb 2020
Posts: 1,503
Mentioned: 26 Post(s)
Tagged: 0 Thread(s)
Quoted: 556 Post(s)
Likes: 0
Liked 521 Times in 328 Posts
Originally Posted by John Nolan View Post
Thanks for that...that's what I imagined, but I can't seem to figure out how to keep the adjustment when I tighten down the jam nut.

I installed the derailleur and claw on the frame, adjusted the pivot bolt, and tried to hold the pivot bolt in place with a hex wrench while tightening the jam nut, but things still ended up too tight.
Well, you need to have it a bit looser before tightening the locknut.

Locknuts work because there is clearance - physical space - between the threads of a bolt and the threads of a nut. A nut by itself (usually) has enough clearance that it is loose; it will turn, and it will also move forwards and backwards along the bolt WITHOUT turning, taking up first the clearance on one side of the thread valleys, then on the other. Locknuts work by forcing the main nut against one side of the valleys, while the locknut gets forced against the other side of the valleys. You get them tight and they stay wherever they wind up being wedged against each other..

Adjusting a pair of locknuts to a particular position along a threaded shaft is a bit of an art. You must start with the main nut a little too loose, so when the jam nut forces it a little further along the shaft it winds up in the correct location. One out of maybe twenty or thirty times I'll be lucky and get it just right the first time - but normally it is lock and check and unlock and tweak and lock and check again until is *is* just right.
oneclick is offline  
Old 04-09-21, 03:30 PM
  #11  
John Nolan 
Senior Member
Thread Starter
 
Join Date: Apr 2007
Location: Ottawa, Canada
Posts: 651

Bikes: Raleigh Classic 15, 84; Miyata Ridge Runner SE, 85; Miyata 610, 86; Miyata 100M, 86; Miyata Valley Runner, 88; Miyata Triple Cross, 89; GT Karakoram, 90; Miyata Elevation 300, 91; Marinoni Touring, 95; Long Haul Trucker, 2013

Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 131 Post(s)
Liked 59 Times in 36 Posts
Thanks, oneclick. Sounds good—Trial and error, that's right up my alley (especially the error!) Just nice to know the procedure isn't in error.
John Nolan is offline  
Old 04-09-21, 03:31 PM
  #12  
Big Block
Senior Member
 
Join Date: Jan 2010
Location: Adelaide, Australia
Posts: 730
Mentioned: 31 Post(s)
Tagged: 0 Thread(s)
Quoted: 171 Post(s)
Liked 64 Times in 36 Posts
Originally Posted by John Nolan View Post
Yes, I have looked at the diagram at Disraeli Gears (BTW your link doesn't work for me, i don't know why.) I didn't have exactly the same arrangement of washers, and I couldn't figure out from that picture how to adjust things.
link issue is that SunTour Small Parts Catalog - 1983? scan 2
is being refused as it is not an https but in http form.
Big Block is offline  
Old 04-09-21, 03:50 PM
  #13  
John Nolan 
Senior Member
Thread Starter
 
Join Date: Apr 2007
Location: Ottawa, Canada
Posts: 651

Bikes: Raleigh Classic 15, 84; Miyata Ridge Runner SE, 85; Miyata 610, 86; Miyata 100M, 86; Miyata Valley Runner, 88; Miyata Triple Cross, 89; GT Karakoram, 90; Miyata Elevation 300, 91; Marinoni Touring, 95; Long Haul Trucker, 2013

Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 131 Post(s)
Liked 59 Times in 36 Posts
Thanks for clearing that up Big Block.
That page one doesn't exactly match my mech—there doesn't seem to be a recess for the pivot bolt, and I'm pretty sure the very thin washers on mine are original, but they don't appear in that diagram.
Still, it does give the general idea.
John Nolan is offline  
Old 04-10-21, 03:16 AM
  #14  
oneclick 
Senior Member
 
Join Date: Feb 2020
Posts: 1,503
Mentioned: 26 Post(s)
Tagged: 0 Thread(s)
Quoted: 556 Post(s)
Likes: 0
Liked 521 Times in 328 Posts
Originally Posted by John Nolan View Post
Thanks for clearing that up Big Block.
That page one doesn't exactly match my mech—there doesn't seem to be a recess for the pivot bolt, and I'm pretty sure the very thin washers on mine are original, but they don't appear in that diagram.
Still, it does give the general idea.
The very thin washers are the shims I mentioned. You use just enough of them to get the clearance desired. Again, the sequence is iterative: try a set of shims - tighten - check - if not correct loose and change shims and try again.
oneclick is offline  
Likes For oneclick:
Old 04-10-21, 06:58 AM
  #15  
PatTheSlat 
Senior Member
 
PatTheSlat's Avatar
 
Join Date: Oct 2011
Location: Youngstown, OH
Posts: 614

Bikes: '63 Schwinn American, '64 DL-1, '65 Schwinn Racer, '73 Super Course, '83 Voyageur SP, '89 Miyata 914, '03 EZ-1, '13 Raleigh i8 Folder

Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 30 Post(s)
Liked 22 Times in 14 Posts
These only pivot to make it easier to get the wheel out, so if you can't get it on there where it pivots freely it won't affect operation at all.
PatTheSlat is offline  
Likes For PatTheSlat:
Old 04-10-21, 08:03 AM
  #16  
John Nolan 
Senior Member
Thread Starter
 
Join Date: Apr 2007
Location: Ottawa, Canada
Posts: 651

Bikes: Raleigh Classic 15, 84; Miyata Ridge Runner SE, 85; Miyata 610, 86; Miyata 100M, 86; Miyata Valley Runner, 88; Miyata Triple Cross, 89; GT Karakoram, 90; Miyata Elevation 300, 91; Marinoni Touring, 95; Long Haul Trucker, 2013

Mentioned: 9 Post(s)
Tagged: 0 Thread(s)
Quoted: 131 Post(s)
Liked 59 Times in 36 Posts
I finally got it adjusted—shuffled around the shims, and worked a bit more carefully. Thanks PatTheSlat: good to know the adjustment isn't too critical.
John Nolan is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.