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 09-16-11, 06:47 PM   #1
Kid A
Thread Starter
TurbineBlade's Avatar
Join Date: Aug 2009
Location: Alexandria, VA
Posts: 1,778
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Derailleur Hanger -- really aligned?

I've had index shifting problems ever since I've had this bike. I got a Park DAG-2 a while back, adjusted everything seemingly perfect, and shifting got better but still not reliable enough to use indexing (friction works fine).

The symptom I have is seemingly perfect indexing 90% of the time, then sudden "pop" noises of the chain not being properly aligned with the cogs.....then a long time with nothing, then it happens again, etc. I've tried several different chains and cassettes -- same problem.

I looked at the hanger upside down and can clearly see that the derailleur and hanger don't appear to be parallel.

Is this normal? I double checked and the 4 cardinal directions lined up with the tire valve are within 2 mm of each other (perfect - according to the tool).

Should I trust my instinct and make the hanger look more parallel even though the tool says otherwise?

Attached Images
File Type: jpg 003.jpg (97.5 KB, 41 views)
TurbineBlade is offline   Reply With Quote
Old 09-16-11, 07:18 PM   #2
Senior Member
gyozadude's Avatar
Join Date: Jun 2011
Location: Sunnyvale, California
Bikes: Bridgestone RB-1, 600, T700, MB-6 w/ Dirt Drops, MB-Zip, Bianchi Limited, Nashbar Hounder
Posts: 1,180
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
The question might be if the bolt on the RD is straight? or is the RD straight? With an old RD, I noticed some play in the bolt that would allow it to pivot a few degrees. So even if the RD hanger is perfect, the RD may not be. And many have a spring plate that the B-screw is attached to that is the facing plate that actually rests on the RD hanger. That plate may result in the whole RD being ever slightly out of plane. I recently bent a vintage frame RD hanger out by 3 degrees out at the bottom, and then gave it about 5 degrees of yaw to port if standing behind and looking forward along the frame. Perfect indexing with an old Shimano RD6207 (600 EX SiS first generation) and BR3300 left/right 7 spd and SunRace 7 spd.
gyozadude is offline   Reply With Quote
Old 09-16-11, 10:23 PM   #3
Old Hammer Boy
Senior Member
Old Hammer Boy's Avatar
Join Date: Aug 2005
Location: Utah
Bikes: Trek, Cannondale Tandem, Surly LHT
Posts: 1,082
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
I would also check the R/D cable, especially under the bottom bracket where things can get pretty gunky. It may be time to replace the complete cable assembly, both sleeve and inner cable. If that doesn't do it, it most certainly will be the R/D. Good luck and let us know what you find...
Old Hammer Boy is offline   Reply With Quote
Old 09-17-11, 06:49 AM   #4
Senior Member
Join Date: Jun 2010
Location: Pearland, Texas
Bikes: Cannondale, Trek, Raleigh, Santana
Posts: 6,754
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 80 Post(s)
TurbineBlade, I've had a similar issue, I think, with two different bikes in the past. On a roadie the cable housing cap had split (plastic) at the RD. This was the first time I'd used shifter specific housing and I moved the metal cap I'd installed on the chainstay to the RD and a spare plastic cap to the chainstay. On the mountain bike the jockey and tension wheels required removal and a clean/relube inside and out, my fault as they were filthy.

bradtx is offline   Reply With Quote
Old 09-17-11, 02:15 PM   #5
Join Date: Sep 2007
Posts: 1,017
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Take the rear derailleur off, then put a spare hub in the dropout and tighten the skewer nice and super tight. Then use a digital caliper to measure whether the hanger is parallel at it's whole length with the hub flange.
pmt is offline   Reply With Quote
Old 09-18-11, 06:43 AM   #6
rogerstg's Avatar
Join Date: Aug 2007
Location: Rhode Island
Posts: 1,800
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Wow, that looks way off. I'm surprised your DAG-2 told you it was parallel with the wheel. You might want to check again. BTW, how true is your wheel (though it would have to be way off to make a diff)?
rogerstg 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 02:46 PM.