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

Straighten RD Hanger

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.

Straighten RD Hanger

Old 07-20-20, 11:39 AM
  #1  
Barry2 
LRP=HR
Thread Starter
 
Join Date: Sep 2019
Location: SF Bay Area
Posts: 531

Bikes: 79 Holdsworth Special, 96 Cannondale F700CAD3, 2011 Cervelo R3, JustGo Runt, Ridley Oval, Kickr Bike 8-)

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 203 Post(s)
Liked 160 Times in 104 Posts
Straighten RD Hanger

Bike fell over on the drive side (my fault) and since then I've been having troubles with gear changes that won't adjust out..
I've measured and the hanger is out of alignment.

The RD hanger is held onto the dropout by two small screws and NOT trapped by the Wheel QR.
All of the stress of straightening the hanger would be taken by the dropout/frame.

With this kind of setup is it really OK to straighten it on the bike or will I break the dropout.

Thanks

Barry
Barry2 is offline  
Old 07-20-20, 11:47 AM
  #2  
trailangel
Senior Member
 
trailangel's Avatar
 
Join Date: Feb 2014
Location: Pasadena, CA
Posts: 4,250

Bikes: Schwinn Varsity

Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 1576 Post(s)
Liked 293 Times in 186 Posts
Standard procedure is straighten the hanger with the rear wheel on the bike.... hanger on bike.
It's hard to align hanger when off the bike.
Without seeing your situation I cannot say for certain.
trailangel is offline  
Old 07-20-20, 11:51 AM
  #3  
leob1
Senior Member
 
Join Date: Jul 2006
Location: Middle of the road, NJ
Posts: 3,067
Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 257 Post(s)
Liked 50 Times in 33 Posts
What is the hanger made of? If it's aluminium, which most if not all are, it will most likely break when you try to bend it back flat. They are replaceable, it's best to just get a new one and replace it.
I've gotten lucky once or twice flattening a hanger, but most of the time they crack.
leob1 is offline  
Old 07-20-20, 11:52 AM
  #4  
davidad
Senior Member
 
Join Date: Feb 2009
Posts: 6,275
Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 439 Post(s)
Likes: 0
Liked 65 Times in 59 Posts
If you don't have the tool you can realign the hanger with a spare wheel if you have one. Remove the der. and thread the spare back wheel into the hanger and use it to bend and check the alignment of the two side by side wheels. It's also a good idea to buy a spare hanger to have on hand.
There are only about 450 different hangers available!
davidad is offline  
Old 07-20-20, 11:55 AM
  #5  
79pmooney
A Roadie Forever
 
79pmooney's Avatar
 
Join Date: Oct 2014
Location: Portland, OR
Posts: 8,630

Bikes: (2) ti TiCycles, 2007 w/ triple and 2011 fixed, 1979 Peter Mooney, ~1983 Trek 420 now fixed and ~1973 Raleigh Carlton Competition gravel grinder

Mentioned: 100 Post(s)
Tagged: 0 Thread(s)
Quoted: 2385 Post(s)
Likes: 0
Liked 828 Times in 558 Posts
I have an aluminum hanger on a ti frame. Bent like yours. Took it off, put it in a vise and gently bent it straight (to a straight edge laid in it) with a large crescent wrench. Put it back on, Much better shifting. I haven't yet built the tool to accurately measure the hanger but I can see that the derailleur lines up far better. A new hanger will go on when I have a chance to go pick it up. (Gotta combine/reduce errands - this COVID thing.) The new one will be steel and I won't have to worry about multiple bends breaking it (within reason).

Ben
79pmooney is online now  
Old 07-20-20, 12:02 PM
  #6  
Barry2 
LRP=HR
Thread Starter
 
Join Date: Sep 2019
Location: SF Bay Area
Posts: 531

Bikes: 79 Holdsworth Special, 96 Cannondale F700CAD3, 2011 Cervelo R3, JustGo Runt, Ridley Oval, Kickr Bike 8-)

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 203 Post(s)
Liked 160 Times in 104 Posts
First thing I did, even before removing the RD was to order another hanger.
The one that is on the bike is out by 3/8". As measured at the rim of the wheel. Upper limit I believe is ~1/8"
So alignment would require 1/2 that... a 3/16" bend.

New and old hangers are metallic and do not stick to a magnet.

If you follow this link
Mine is the 156 type and so only partially trapped by the rear wheel
Unlike the 101 type that is completely trapped by the rear wheel.

I could just install the new one, but I was under the impression that new hangers still need aligning?

Barry
Barry2 is offline  
Old 07-20-20, 12:26 PM
  #7  
trailangel
Senior Member
 
trailangel's Avatar
 
Join Date: Feb 2014
Location: Pasadena, CA
Posts: 4,250

Bikes: Schwinn Varsity

Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 1576 Post(s)
Liked 293 Times in 186 Posts
Ya, a new hanger would still need to be checked for alignment with the wheel and hanger on the bike.
If your hanger is really bent a lot, take it off and straighten in a vise or with crescent wrench or something.
Put it back on the bike with wheel on and touch it up a little.
trailangel is offline  
Old 07-20-20, 03:29 PM
  #8  
Barry2 
LRP=HR
Thread Starter
 
Join Date: Sep 2019
Location: SF Bay Area
Posts: 531

Bikes: 79 Holdsworth Special, 96 Cannondale F700CAD3, 2011 Cervelo R3, JustGo Runt, Ridley Oval, Kickr Bike 8-)

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 203 Post(s)
Liked 160 Times in 104 Posts
Chicken

Played chicken.... went to my usual LBS.

Walked in the door and was told: "It might break when we straighten it"
I replied: "I've got a new one in my pocket"
Reply came back: "you have a spare, then there is no way this one will break!"

Total time to straighten, 10mins or less, the deed is done.

Thanks guys.

Barry

Last edited by Barry2; 07-20-20 at 04:29 PM.
Barry2 is offline  
Old 07-20-20, 03:36 PM
  #9  
fietsbob
Banned
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Posts: 43,598

Bikes: 8

Mentioned: 197 Post(s)
Tagged: 0 Thread(s)
Quoted: 7607 Post(s)
Liked 1,277 Times in 798 Posts
Your rear wheel is the plane of reference that you use to get the derailleur hanger aligned with the shop tool..

More 'speeds' in the cassette, the more having the job done accurately, matters ..
fietsbob is offline  
Old 07-20-20, 03:43 PM
  #10  
aggiegrads
Senior Member
 
Join Date: Oct 2009
Location: Sherwood, OR
Posts: 1,001
Mentioned: 19 Post(s)
Tagged: 0 Thread(s)
Quoted: 191 Post(s)
Liked 99 Times in 73 Posts
Originally Posted by 79pmooney View Post
I have an aluminum hanger on a ti frame. Bent like yours. Took it off, put it in a vise and gently bent it straight (to a straight edge laid in it) with a large crescent wrench. Put it back on, Much better shifting. I haven't yet built the tool to accurately measure the hanger but I can see that the derailleur lines up far better. A new hanger will go on when I have a chance to go pick it up. (Gotta combine/reduce errands - this COVID thing.) The new one will be steel and I won't have to worry about multiple bends breaking it (within reason).

Ben
Ben, PM me if you need to borrow a hangar alignment gauge.
aggiegrads is offline  
Old 07-20-20, 03:48 PM
  #11  
aggiegrads
Senior Member
 
Join Date: Oct 2009
Location: Sherwood, OR
Posts: 1,001
Mentioned: 19 Post(s)
Tagged: 0 Thread(s)
Quoted: 191 Post(s)
Liked 99 Times in 73 Posts
Originally Posted by Barry2 View Post
Walked in the door and was told: "It might break when we straighten it"
I replied: "I've got a new one in my pocket"
Reply came back: "you have a spare, then there is no way this one will break!"
I had the same thing happen to my cross race bike (Kona Jake the Snake), I bent the hangar, pulled the RD into the spokes, and had to rebuild the wheel. Even the chain bent.

Replaced the RD, chain, a few spokes, and ordered a new Aluminum hangar. I was able to straighten the old hangar and have crashed it twice since and straightened the hangar.

If I didn't have a new one sitting in my parts bin, I'm sure that it would have cracked on my first try.
aggiegrads is offline  
Old 07-20-20, 06:35 PM
  #12  
zacster
Senior Member
 
Join Date: Jul 2004
Location: Brooklyn NY
Posts: 6,925
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 22 Post(s)
Liked 201 Times in 163 Posts
I bought the tool years ago and check mine every once in a while, maybe yearly. Of course since I have the tool I've never needed to realign any bike after the first use.
zacster is offline  
Old 07-20-20, 07:51 PM
  #13  
aggiegrads
Senior Member
 
Join Date: Oct 2009
Location: Sherwood, OR
Posts: 1,001
Mentioned: 19 Post(s)
Tagged: 0 Thread(s)
Quoted: 191 Post(s)
Liked 99 Times in 73 Posts
Originally Posted by zacster View Post
I bought the tool years ago and check mine every once in a while, maybe yearly. Of course since I have the tool I've never needed to realign any bike after the first use.
You must not have kids.
aggiegrads is offline  
Old 07-20-20, 08:22 PM
  #14  
Barry2 
LRP=HR
Thread Starter
 
Join Date: Sep 2019
Location: SF Bay Area
Posts: 531

Bikes: 79 Holdsworth Special, 96 Cannondale F700CAD3, 2011 Cervelo R3, JustGo Runt, Ridley Oval, Kickr Bike 8-)

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 203 Post(s)
Liked 160 Times in 104 Posts
Originally Posted by aggiegrads View Post
You must not have kids.
Because kids bend alot-o-hangers ????



Barry
Barry2 is offline  
Old 07-20-20, 08:27 PM
  #15  
aggiegrads
Senior Member
 
Join Date: Oct 2009
Location: Sherwood, OR
Posts: 1,001
Mentioned: 19 Post(s)
Tagged: 0 Thread(s)
Quoted: 191 Post(s)
Liked 99 Times in 73 Posts
Originally Posted by Barry2 View Post
Because kids bend alot-o-hangers ????



Barry
Kids and adults that act like kids.
aggiegrads is offline  
Old 07-20-20, 09:33 PM
  #16  
zacster
Senior Member
 
Join Date: Jul 2004
Location: Brooklyn NY
Posts: 6,925
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 22 Post(s)
Liked 201 Times in 163 Posts
I have 3 adult kids, 2 at home at the moment. But even when they were little they never went near my bikes. They each have their own road bikes now, and of course I'm still the master mechanic for them.
zacster is offline  
Old 07-21-20, 07:51 AM
  #17  
JohnDThompson 
Old fart
 
JohnDThompson's Avatar
 
Join Date: Nov 2004
Location: Appleton WI
Posts: 21,707

Bikes: Several, mostly not name brands.

Mentioned: 126 Post(s)
Tagged: 0 Thread(s)
Quoted: 2240 Post(s)
Liked 629 Times in 423 Posts
Originally Posted by trailangel View Post
Standard procedure is straighten the hanger with the rear wheel on the bike.... hanger on bike.
+1 this. A trued, properly dished wheel serves as a reference plane for the hanger alignment tool.
JohnDThompson is online now  
Old 07-21-20, 09:32 AM
  #18  
Retro Grouch 
Senior Member
 
Retro Grouch's Avatar
 
Join Date: Feb 2004
Location: St Peters, Missouri
Posts: 29,929

Bikes: Catrike 559 I own some others but they don't get ridden very much.

Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 1444 Post(s)
Liked 352 Times in 217 Posts
1. Can you ride your bike the way that it is now? If your answer is "no" you have nothing to lose by trying to straighten your derailleur hanger. FWIW, I've bent back some pretty seriously bent aluminum hangers and have never had one break on me - yet.

2. How many rear cogs do you have? Up to 8, I can eyeball the alignment adequately. Don't try to bend the hanger without having a bolt in the derailleur mounting hole because you might ovalize the hole. I leave the derailleur in place and bend it with my hands if I can. Otherwise I clamp a big Crescent wrench over the derailleur. I don't even try that with more than 8 cogs because the cogs are so closely spaced that you have to be pretty accurate. I have the Park Tool alignment tool which works well.

3. If you don't have an alignment gauge, you are still in luck. The work around is to use your front wheel. Remove the quick release and screw your front wheel axle into the derailleur hanging hole. Make your front wheel totally parallel to your back wheel and you're good-t0-g0.
__________________
My greatest fear is all of my kids standing around my coffin and talking about "how sensible" dad was.
Retro Grouch is online now  
Old 07-21-20, 09:57 AM
  #19  
davidad
Senior Member
 
Join Date: Feb 2009
Posts: 6,275
Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 439 Post(s)
Likes: 0
Liked 65 Times in 59 Posts
Originally Posted by Retro Grouch View Post
1. Can you ride your bike the way that it is now? If your answer is "no" you have nothing to lose by trying to straighten your derailleur hanger. FWIW, I've bent back some pretty seriously bent aluminum hangers and have never had one break on me - yet.

2. How many rear cogs do you have? Up to 8, I can eyeball the alignment adequately. Don't try to bend the hanger without having a bolt in the derailleur mounting hole because you might ovalize the hole. I leave the derailleur in place and bend it with my hands if I can. Otherwise I clamp a big Crescent wrench over the derailleur. I don't even try that with more than 8 cogs because the cogs are so closely spaced that you have to be pretty accurate. I have the Park Tool alignment tool which works well.

3. If you don't have an alignment gauge, you are still in luck. The work around is to use your front wheel. Remove the quick release and screw your front wheel axle into the derailleur hanging hole. Make your front wheel totally parallel to your back wheel and you're good-t0-g0.
The front won't work because of the different size axle (9mm). The der. bolt is 10mm.
davidad is offline  
Old 07-21-20, 10:56 AM
  #20  
joeruge
Senior Member
 
Join Date: Jan 2006
Posts: 121
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 45 Post(s)
Liked 11 Times in 10 Posts
RD Hanger

It is my understanding that these aluminum RD hangers are designed to be realigned on the bike with the rear wheel in place and the QR clamped tight.

Minor 'injuries' can be corrected several times before you have to worry about replacing the hanger. Obviously, one big accident can spell the end of the hanger, but it's worth a try. If it's going to break, it will likely happen when you bend it back, and not so likely to happen while riding the bike. Putting a severely bent hanger in a vice to get it close, is not a bad idea, bit you will still have to do final adjustment when it's on the frame.

For various reasons, even putting a new hanger on the frame is no guarantee it will be aligned when tightened up. A new one will also have to be checked and possibly adjusted.
joeruge is offline  
Old 07-21-20, 08:49 PM
  #21  
WizardOfBoz
Generally bewildered
 
WizardOfBoz's Avatar
 
Join Date: Aug 2015
Location: Eastern PA, USA
Posts: 2,790

Bikes: 2014 Trek Domane 6.9, 1999 LeMond Zurich, 1978 Schwinn Superior

Mentioned: 20 Post(s)
Tagged: 0 Thread(s)
Quoted: 1039 Post(s)
Liked 241 Times in 178 Posts
Originally Posted by barry2 View Post
went to my usual lbs. Walked in the door and was told: "it might break when we straighten it"
i replied: "i've got a new one in my pocket"
reply came back: "you have a spare, then there is no way this one will break!"
lol.
WizardOfBoz 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 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.