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

Can't get Rear Derailleur working properly

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.

Can't get Rear Derailleur working properly

Old 05-14-12, 09:51 AM
  #1  
thnksfrtht
Junior Member
Thread Starter
 
Join Date: Dec 2011
Location: Edmonton, Alberta
Posts: 7

Bikes: Gary Fisher Hi-Fi; Cervelo P2

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Can't get Rear Derailleur working properly

Hello, apologies in advance if this is an easy answer.

I've been trying to get my rear derailleur working properly, but am just getting frustrated. The H, L and B screws are all in line. I have the tension as tight as I can get it on the cable, and the first couple of shifts work smoothly. Then, at about the 3rd (or 4th) cog, it hesitates. I'll then use the barrell adjuster to tighten until the chain jumps up a gear. After that, the cable is too tight, and if I shift down to the smallest cog, it won't shift past the second smallest.

My cassette is new, my rear D is fairly new (and straight), and my cable is brand new.

Any help is appreciated - I don't know what's causing the trouble.
thnksfrtht is offline  
Old 05-14-12, 09:56 AM
  #2  
DannoXYZ 
Senior Member
 
DannoXYZ's Avatar
 
Join Date: Jul 2005
Location: Saratoga, CA
Posts: 11,736
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 108 Post(s)
Liked 5 Times in 4 Posts
List all your components, there may be mismatch of some kind.
DannoXYZ is offline  
Old 05-14-12, 10:00 AM
  #3  
thnksfrtht
Junior Member
Thread Starter
 
Join Date: Dec 2011
Location: Edmonton, Alberta
Posts: 7

Bikes: Gary Fisher Hi-Fi; Cervelo P2

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Unsure of cassette (I bought at the tail end of last season), I just know it's nine-speed. Derailleur is XT Deore. Shimano Chain.
thnksfrtht is offline  
Old 05-14-12, 10:00 AM
  #4  
Homebrew01
Super Moderator
 
Homebrew01's Avatar
 
Join Date: Jul 2004
Location: Ffld Cnty Connecticut
Posts: 21,633

Bikes: Old Steelies I made, Old Cannondales

Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 1053 Post(s)
Liked 464 Times in 335 Posts
https://www.parktool.com/blog/repair-help
__________________
Bikes: Old steel race bikes, old Cannondale race bikes, less old Cannondale race bike, crappy old mtn bike.

FYI: https://www.bikeforums.net/forum-sugg...ad-please.html
Homebrew01 is offline  
Old 05-14-12, 10:07 AM
  #5  
FBinNY 
Senior Member
 
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 35,964

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

Mentioned: 124 Post(s)
Tagged: 1 Thread(s)
Quoted: 4362 Post(s)
Likes: 0
Liked 27 Times in 26 Posts
You may have the cable adjustment off by one gear position. Slacken the cable slightly, shift so the chain is on the second smallest sprocket, set the lever for the 3rd to high gear (7 for a 9s), and adjust the barrel adjuster while pedaling until it shifts. Now find tune around the shifting between the 2 and 3rd smallest sprockets in both directions, and the rest should follow.

If not, check that the cable runs smoothly, the gear hanger adjustment, the "B" screw adjustment, and just in case use an improvised feeler gauge to check that the gap between the cassette sprockets is uniform.
__________________
FB
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 offline  
Old 05-14-12, 10:23 AM
  #6  
thnksfrtht
Junior Member
Thread Starter
 
Join Date: Dec 2011
Location: Edmonton, Alberta
Posts: 7

Bikes: Gary Fisher Hi-Fi; Cervelo P2

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Thanks for the responses - I'll try these suggestions tonight.

Again, appreciated.
thnksfrtht is offline  
Old 05-14-12, 10:34 AM
  #7  
JonathanGennick 
Senior Member
 
JonathanGennick's Avatar
 
Join Date: Apr 2007
Location: Munising, Michigan, USA
Posts: 4,131

Bikes: Priority 600, Priority Continuum, Devinci Dexter

Mentioned: 14 Post(s)
Tagged: 0 Thread(s)
Quoted: 685 Post(s)
Likes: 0
Liked 55 Times in 37 Posts
Originally Posted by thnksfrtht View Post
I'll then use the barrell adjuster to tighten until the chain jumps up a gear.
If I turn the barrell adjuster enough to spark the shift, it is often too much. My technique is to: 1) Turn barrell adjuster a click or two (or whatever), 2) reverse course a few cogs, 3) come at the shift again to see whether it works.

Have you put a hanger alignment gauge on the hanger to verify alignment? What you're experiencing seems pretty classic for a misaligned hanger.
JonathanGennick is offline  
Old 05-14-12, 10:35 AM
  #8  
Sixty Fiver
Bicycle Repair Man !!!
 
Sixty Fiver's Avatar
 
Join Date: Sep 2007
Location: YEG
Posts: 27,268

Bikes: See my sig...

Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 58 Post(s)
Liked 27 Times in 17 Posts
FB always give great advice.

Sometimes it is easier to start from 0... release the cable and make sure the shifter is in the right position.

The cable adjustment screw on the derailleur should be turned out from it's stop 4-5 turns to give you some +/- adjustment when you are setting things up and you can usually make fine adjustments at the lever.

A really important aspect of indexed systems is ensuring that your derailleur and hangar are aligned... a bent hanger will defeat your best efforts at trying to dial things in every time.

If you are really still fubar after this send me a smoke signal as it looks like we hail from the same great city and would be happy to take a look at things for you... my shop is north central (Kingsway) and I also volunteer at the Bicycle Commuter's Society and since we opened the north location I am usually there.

The crew at the south side is pretty good and they have expanded hours there and would trust that they could remedy most issues.
Sixty Fiver is offline  
Old 05-14-12, 02:48 PM
  #9  
thnksfrtht
Junior Member
Thread Starter
 
Join Date: Dec 2011
Location: Edmonton, Alberta
Posts: 7

Bikes: Gary Fisher Hi-Fi; Cervelo P2

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Hey, @Sixty - I cant PM you, but I wanted to say thanks for the descriptive reply - and I'd love to make visit your shop! Hit me with your details!

Regards!
thnksfrtht is offline  
Old 05-14-12, 09:30 PM
  #10  
Standard Issue
Senior Member
 
Join Date: Aug 2009
Location: Albany, NY
Posts: 243

Bikes: 89 Bianchi Campione d'Italia upgraded with 10 speed Ultegra/105, '92 Trek 1100 8 speed, bar end shifters

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
I had similar shifting issues. The first time it was because I was using a suntour rear D with shimano shifters/cassette. The 2nd time switching out the chain solved the issue. You'll have to try every component to really solve the issue. It may take a while a cost a few bucks but eventually you'll figure it out.
Standard Issue is offline  
Old 05-14-12, 09:36 PM
  #11  
FBinNY 
Senior Member
 
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 35,964

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

Mentioned: 124 Post(s)
Tagged: 1 Thread(s)
Quoted: 4362 Post(s)
Likes: 0
Liked 27 Times in 26 Posts
Originally Posted by Standard Issue View Post
You'll have to try every component to really solve the issue. It may take a while a cost a few bucks but eventually you'll figure it out.
This kind of trial and error is the most expensive way to fix a mechanical problem.

Take the time to analyze the possibilities, and start by testing and ruling in or out those things that can be done for free, ie. adjustments or measurements. Only when have you narrowed the issue down to a short list or single proven culprit should you spend cash to replace it.

Most problems, especially things like erratic shifting don't call for new parts, just better adjustments of what you have.
__________________
FB
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.

Last edited by FBinNY; 05-14-12 at 09:43 PM.
FBinNY is offline  
Old 05-14-12, 10:29 PM
  #12  
Pepper Grinder
Senior Member
 
Join Date: Aug 2007
Posts: 471
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Cable friction. Old housing? Lube inner cable with very thin coat of teflon-impregnated dry lube/wax lube. Also be sure to lube bottom bracket cable guide.
Pepper Grinder is offline  
Old 05-14-12, 11:39 PM
  #13  
ruirui
need to go out and ride..
 
ruirui's Avatar
 
Join Date: Mar 2004
Location: Bay Area, CA
Posts: 1,435

Bikes: 2011 Scott Addict R1, 2014 Redline Conquest Team, 2015 BMC TMR02

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 19 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
you might want yo check this video out: adjusting deraileur
ruirui is offline  
Old 05-15-12, 12:28 AM
  #14  
Sixty Fiver
Bicycle Repair Man !!!
 
Sixty Fiver's Avatar
 
Join Date: Sep 2007
Location: YEG
Posts: 27,268

Bikes: See my sig...

Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 58 Post(s)
Liked 27 Times in 17 Posts
Originally Posted by ruirui View Post
you might want yo check this video out: adjusting deraileur
That is a good video but does not address troubleshooting things like bent hangars and differs from my method when it comes to setting the barrel adjuster... I can usually install a cable and by feel can usually have it at nearly perfect tension and only have to make small adjustments and like to set that barrel adjuster so there is room to go up or down +/- in case the cable is a little too tight and needs to be backed off a little.

I do this with all barrel adjusters so I can increase or decrease cable tension during set up.

I might be the odd duck in this but this has been working for me for years.

In re-reading the OP my thought is that since the OP's bike shifts well to the middle of the cassette and then goes off that there is an alignment issue with the hangar or that the derailleur has been bent but without seeing things closely or in person it can be hard to tell what is causing the issue.

Could even be a mismatch between the shifter and cassette... you can get 8 and 9 speed shifters to shift 9 and 8 reasonably well until you get to the middle and then things can go off just a little.
Sixty Fiver is offline  
Old 05-15-12, 03:34 AM
  #15  
Kimmo 
bike whisperer
 
Kimmo's Avatar
 
Join Date: Dec 2009
Location: Melbourne, Oz
Posts: 8,972

Bikes: https://weightweenies.starbike.com/forum/viewtopic.php?f=10&t=152015&p=1404231

Mentioned: 14 Post(s)
Tagged: 0 Thread(s)
Quoted: 1108 Post(s)
Liked 400 Times in 287 Posts
Given your components are compatible, there's not much else it can be other than cable friction.

You first need to either confirm or eliminate this possibility.

With the bike upside down or in a stand, have someone turn the cranks so you can shift while pulling the derailleur outboard to maximise cable tension.

If this makes the bike shift fine, the signal isn't getting through to the derailleur properly - there's too much friction for the derailleur's return spring to overcome.

If it doesn't, you likely have a bent hanger, or just maybe something less obvious.
Kimmo is offline  
Old 05-15-12, 05:19 AM
  #16  
JonathanGennick 
Senior Member
 
JonathanGennick's Avatar
 
Join Date: Apr 2007
Location: Munising, Michigan, USA
Posts: 4,131

Bikes: Priority 600, Priority Continuum, Devinci Dexter

Mentioned: 14 Post(s)
Tagged: 0 Thread(s)
Quoted: 685 Post(s)
Likes: 0
Liked 55 Times in 37 Posts
Originally Posted by Sixty Fiver View Post
...and like to set that barrel adjuster so there is room to go up or down +/- in case the cable is a little too tight and needs to be backed off a little.
Interesting you mention that, because I've taken to doing the same. I sometimes have wondered whether I'm the only one.
JonathanGennick is offline  
Old 05-15-12, 05:33 AM
  #17  
Amesja
Cottered Crank
 
Amesja's Avatar
 
Join Date: Aug 2010
Location: Chicago
Posts: 3,493

Bikes: 1954 Raleigh Sports 1974 Raleigh Competition 1969 Raleigh Twenty 1964 Raleigh LTD-3

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Likes: 0
Liked 3 Times in 2 Posts
Make sure the cable housing at the RD isn't getting caught up and can move freely as the derailleur goes through its motions. I had a case the other day where the cable was getting just barely snagged by the hardware that had been used to mount the rear rack. It would get snagged just very slightly by the bolt head and it would cause the tension to be messed up in certain derailleur positions until it popped itself free. Sometimes a very small thing like this will cause enough of a drag or change in tension on the cable as to make it very hard to tune the shifting to work consistently across the the entire spectrum of gears and derailleur positions.
Amesja is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
hrdknox1
Bicycle Mechanics
15
06-03-19 09:45 AM
jaris93
Bicycle Mechanics
8
10-08-17 11:13 AM
grall1126
Bicycle Mechanics
5
02-07-10 05:21 PM

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.