Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

Index to Non-Index Shifting

Notices
Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

Index to Non-Index Shifting

Old 06-24-23, 12:48 PM
  #1  
Senior Member
Thread Starter
 
Join Date: Aug 2019
Posts: 1,143
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 424 Post(s)
Liked 508 Times in 303 Posts
Index to Non-Index Shifting

My 31 year old Suntour 7-speed index shifting derailleur seems to be auto converting to fiction shifting.
Before I frighten it by threatening to "fix" it I thought I would consult the collective genius of the Forum for advice.
Ignore it, tighten this, lube that, buy a new bike?
Thanks in advance.
Pratt is offline  
Old 06-24-23, 01:16 PM
  #2  
Expired Member
 
shelbyfv's Avatar
 
Join Date: Jun 2007
Location: TN
Posts: 11,800
Mentioned: 41 Post(s)
Tagged: 0 Thread(s)
Quoted: 3770 Post(s)
Liked 5,721 Times in 2,888 Posts
Originally Posted by Pratt
My 31 year old Suntour 7-speed index shifting derailleur seems to be auto converting to fiction shifting..
Hard to see how the derailleur could be at fault. Are you sure it's not the shifter?
shelbyfv is offline  
Likes For shelbyfv:
Old 06-24-23, 01:32 PM
  #3  
señor miembro
 
SurferRosa's Avatar
 
Join Date: Dec 2018
Location: Pac NW
Posts: 6,661

Bikes: '70s - '80s Campagnolo

Mentioned: 93 Post(s)
Tagged: 0 Thread(s)
Quoted: 3922 Post(s)
Liked 6,560 Times in 3,251 Posts
"Non-index" = friction.

Many old-school down tube shifters could be switched between the two, even on-the-fly.

Pratt, pics are always helpful. Saves a lot of time.
SurferRosa is offline  
Old 06-24-23, 03:23 PM
  #4  
Senior Member
 
Join Date: Mar 2012
Posts: 998
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 511 Post(s)
Likes: 0
Liked 651 Times in 365 Posts
Originally Posted by shelbyfv
Hard to see how the derailleur could be at fault. Are you sure it's not the shifter?
Almost certainly the shifter. May be worn out, or maybe just needs a clean and lube.
KerryIrons is offline  
Old 06-24-23, 03:30 PM
  #5  
Senior Member
 
Join Date: Jan 2016
Posts: 901
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 361 Post(s)
Liked 336 Times in 246 Posts
Originally Posted by Pratt
My 31 year old Suntour 7-speed index shifting derailleur seems to be auto converting to fiction shifting.
Before I frighten it by threatening to "fix" it I thought I would consult the collective genius of the Forum for advice.
Ignore it, tighten this, lube that, buy a new bike?
Thanks in advance.
The Suntour Accushift index system usually has the 'clicks' on the shifter, not the RD side. The RD just moves into the proper position by the correct amount of cable pull. The RD should just move smoothly, no detents on that end.

You could disconnect the cable at the RD and check that the shifter 'clicking' properly.
KCT1986 is offline  
Old 06-24-23, 03:38 PM
  #6  
Senior Member
Thread Starter
 
Join Date: Aug 2019
Posts: 1,143
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 424 Post(s)
Liked 508 Times in 303 Posts
Thanks.
I have visions of small, obscure parts flying off into the wild blue yonder upon disassembly.
Pratt is offline  
Old 06-24-23, 04:22 PM
  #7  
Senior Member
 
Join Date: Jan 2016
Posts: 901
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 361 Post(s)
Liked 336 Times in 246 Posts
Originally Posted by Pratt
Thanks.
I have visions of small, obscure parts flying off into the wild blue yonder upon disassembly.
A little more info about what is happening would be helpful.

Also, the setup that you are using. Downtube shifter?, MTB shifter? Model #?, RD? Freewheel type? Cable & housing type & condition?

There are a few people on here that are familiar with Accushift in certain configurations and may be able to help you if more detail is provided.
KCT1986 is offline  
Old 06-24-23, 04:31 PM
  #8  
Senior Member
 
Trakhak's Avatar
 
Join Date: Jan 2005
Location: Baltimore, MD
Posts: 5,549
Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 2581 Post(s)
Liked 3,097 Times in 1,762 Posts
Originally Posted by Pratt
Thanks.
I have visions of small, obscure parts flying off into the wild blue yonder upon disassembly.
As has been pointed out repeatedly in this thread, the problem is almost certainly not in the shifter. Couldn't hurt to drip some lubricant into the shifter without disassembling it, though. In any event, don't disassemble it.

Far more likely: the cable housing may be kinked or whatever lubrication it might have had at one time may have evaporated. The inner wire may be kinked.
Trakhak is offline  
Old 06-24-23, 04:35 PM
  #9  
Senior Member
 
Trakhak's Avatar
 
Join Date: Jan 2005
Location: Baltimore, MD
Posts: 5,549
Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 2581 Post(s)
Liked 3,097 Times in 1,762 Posts
Originally Posted by SurferRosa
"Non-index" = friction.

Many old-school down tube shifters could be switched between the two, even on-the-fly.

Pratt, pics are always helpful. Saves a lot of time.
Good call, especially for Suntour shifters of that era.

Pratt, do a search for information on your shifter model (the model number should be visible). You'll likely be able to find instructions on how to switch the (right-side) shifter between indexing and friction.

Some models can be switched to a "soft" click setting---the lever ratchets, but the detents do not correspond to indexing positions.
Trakhak is offline  
Old 06-24-23, 09:29 PM
  #10  
Senior Member
 
grumpus's Avatar
 
Join Date: Apr 2016
Posts: 1,368
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 549 Post(s)
Liked 484 Times in 371 Posts
Originally Posted by Trakhak
As has been pointed out repeatedly in this thread, the problem is almost certainly not in the shifter.
Actually the consensus seems to be that it probably is the shifter.
Originally Posted by Trakhak
Couldn't hurt to drip some lubricant into the shifter without disassembling it, though. In any event, don't disassemble it.
That's reasonable advice. My success rate reassembling shifters is less than 100%.
Originally Posted by Trakhak
Far more likely: the cable housing may be kinked or whatever lubrication it might have had at one time may have evaporated. The inner wire may be kinked.
This is quite likely the case.
grumpus is offline  
Old 06-26-23, 09:41 PM
  #11  
Senior Member
 
oldbobcat's Avatar
 
Join Date: Jul 2005
Location: Boulder County, CO
Posts: 4,433

Bikes: '80 Masi Gran Criterium, '12 Trek Madone, early '60s Frejus track

Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 523 Post(s)
Liked 460 Times in 346 Posts
Originally Posted by KCT1986
The Suntour Accushift index system usually has the 'clicks' on the shifter, not the RD side.
Usually.

The derailleur moves the chain sideways. The cable pulls the derailleur cage. The shift lever pulls the cable. It either has clicks that determine how much cable gets pulled, or the user does that. It's usually the case that when a rear derailleur no longer indexes properly that something whacked it and bent it, or the hanger.
oldbobcat 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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.