Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  

Go Back   > >

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.

User Tag List

Thread Tools Search this Thread
Old 03-09-14, 03:26 PM   #1
Senior Member
Thread Starter
TheEnthusiast's Avatar
Join Date: Nov 2013
Location: Willow Springs, MO
Bikes: 1984 Maruishi RX-4 Sport 12 speed, 1985 Schwinn Sprint 12 Speed, 1987 Cannondale ST-500 14 speed
Posts: 73
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
RD still wont shift gears Schwinn 12 speed

I have a Suntour allegro 12 speed rear derailleur that wont shift it just stays in the center gear shown. I can push down all the way on the shifting lever on the handlebar stem. RD remains motionless as you try to shift. Its not the tension screw either because I can loosen and tighten.
Maybe its the H & L limit screws? They're hard to turn.

Attached Images
File Type: jpg IMG_20140309_155416.jpg (96.2 KB, 10 views)
File Type: jpg IMG_20140309_155817.jpg (93.6 KB, 9 views)
File Type: jpg IMG_20140309_155823.jpg (87.6 KB, 11 views)
TheEnthusiast is offline   Reply With Quote
Old 03-09-14, 03:38 PM   #2
Senior Member
Join Date: Apr 2009
Location: New Rochelle, NY
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Posts: 30,347
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 600 Post(s)
OK, start with a basic process of elimination. Remove or slacken the cable, and see if you can get the RD to move by pushing the lower body in while pedaling. If so, and if with the cable off, the RD can be pushed in and springs back, then it's OK.

OTOH - if you cannot move the RD by pushing the lower body in, then you need to look within it for why. Possibly a prior owner brought the limits in against each t er to lock it in position, or possibly the pivots are corroded and bound.

Either way, the detective process starts with narrowing the list of suspects to a few, then checking them out one by one.
Chain-L site

An ounce of diagnosis is worth a pound of cure.

“Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin

“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FBinNY is online now   Reply With Quote
Old 03-09-14, 03:39 PM   #3
Senior Member
Join Date: Jan 2014
Posts: 272
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
With the chain off check to see if the pivots move freely. I've seen a ton of old derailleurs gummed or rusted up. If frozen then remove and spray/soak in wd40 or your preferred penetrating oil. I've saved a few by doig this. Sometimes the pivots are rusted solid and depending on the model it may not be worth taking apart to rebuild. The lube will probably help free up the limit screws as well.
Antieverything is offline   Reply With Quote
Old 03-11-14, 03:36 PM   #4
Junior Member
Join Date: Mar 2014
Location: East london
Posts: 8
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
It could be for a number of reasons but it sounds like the High and Low screws are in to far. it also could be a stiff cable its worth checking the cables moves freely
icon_cycles is offline   Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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

All times are GMT -6. The time now is 02:07 PM.