48. How to Align a Rear Derailleur Hanger

Derailleur hangers are easily bent and can cause shifting problems.

IMPORTANT: Nuts and bolts on your bike should always be tightened to the manufacturer's specifications.
How to Align a Rear Derailleur Hanger
DVD Vol. 2 DVD Volume 2
This video is available on DVD

50% of the cost of the bicycle featured in this video was donated by JensonUSA.

Today we’ll learn how to straighten integrated derailleur hangers. Shifting problems caused by a bent derailleur hanger are quite common. This can happen if your bike is dropped, crashed or bumped, or if it was poorly aligned at the manufacturer. The result is poor shifting even after all other adjustments have been made.

Tools

For this job you’ll need a repair stand and a hanger alignment gauge like this one called the DAG-2 from Park Tool. It costs about $50 dollars. When compared to bike shop labor charges, it will pay for itself after 3-4 uses. You’ll also need a 5mm hex key for the derailleur mounting bolt, and a string or small strap to hold the derailleur out of the way while you align the hanger.

It is important to make sure your rear wheel is true and properly mounted in the frame dropouts, as the alignment tool compares the derailleur hanger to the rim surface. See the tutorials titled How to Remove and Install Your Wheels and How to True a Wheel.

Tool Installation

The first step is to shift the rear derailleur onto the smallest sprocket and then remove the rear derailleur by turning the mounting bolt all the way counter-clockwise. There is no need to remove the shift cable or chain. Then tie the derailleur up onto the frame to keep it out of the way. If you have a replaceable derailleur hanger, you’ll first want to make sure the bolts holding it in place are properly tightened so they don’t move.

Now thread the tool’s shaft all the way into the hanger threads by turning it carefully clockwise into where the derailleur was mounted. If it doesn’t thread in smoothly, the threads may be damaged and need to be chased with a tap. We’ll cover this in a future tutorial. Do not use the tool’s threads as a thread chaser.

We’ll be checking the alignment at four different places on the rim: the 9 o’clock and 3 o’clock for horizontal alignment, and the 12 o’clock and 6 o’clock for vertical alignment. When aligned correctly, the alignment tool's indicator will be roughly the same distance from the rim at all four locations.

Horizontal Alignment

For horizontal alignment, move the alignment tool’s arm to the 9 o’clock position and rotate the wheel so the valve is at the same spot. Loosen the knob and slide the indicator so it contacts the outside edge of the rim, and then tighten the knob again to hold the indicator in place. Now rotate the tool arm and valve around to the 3 o’clock position and see where the indicator sits. If the tip of the indicator is within 4mm of the rim on this side then the horizontal alignment is ok. If the difference is more or less than 4mm, carefully pull or push the tool’s arm, using it as a lever to slightly bend the hanger in the right direction, and then re-check the alignment on both sides.

You may need to repeat this process a few times until the alignment is within range. It’s important not to bend the hanger too much with the alignment tool. It’s best to bend it a little bit and then have to bend it some more, rather than bending it too much and having to bend it back again.

Vertical Alignment

For vertical alignment, keep the indicator in the same position and then check the 12 o’clock and 6 o’clock positions the same way we did for the horizontal alignment. Always remember to move the air valve along with the indicator and place the indicator at the outside edge of the rim.

Once the hanger is aligned and within 4mm both horizontally and vertically, unthread the alignment tool. Apply a little waterproof grease to the derailleur's mounting bolts threads and begin threading it back in clockwise. Make sure the B-screw adjustment is sitting behind the derailleur hanger. Then tighten the derailleur to the specified torque, usually around 8-10 Newton Meters or 70-90 Inch Pounds.

Tags

Related Links

Discuss this topic in the Derailleur Forums

07/17 Front derailleur can't shift from inner chainring to outer...sometimes

So I'm having a very strange problem. I have an old 10 speed Chimo with friction shifters on the stem. A few months back I noticed that when I downshift to the inner chainring, my front derailleur can't shift it back up to the outer chainring. I put it off and only used 5 gears till I tried to fix it today. I flipped the bike upside down and played around with it and it shifted perfectly back and forth. I then righted the bike and had someone hold up the back tire. It also shifted just fine. But when I rode it, once again it refused to shift back up to the outer chainring. Any ideas what this... Read more >>

06/09 Front derailleur drags on middle chainring?

Hi guys -- I'm new to the forum. Thanks for reading.

I'm fixing up a bike I've had for ~15 years that, sadly, I wasn't able to maintain. The bike is an 18-speed Royce Union mountain bike. Aside from new tubes/tires and a new chain, everything else is original (thumb shifters, both derailleurs are Shimano).

The original chain was just too rusted, so I replaced it, and it runs nicely now. Almost. It's fine on the granny chainring, and it's fine on the big ring, but when it's on the middle ring (the one that I tend to use the most), the chain drags across the inside... Read more >>

06/05 Rear derailleur rolling chain off

Hello I recently got my hands on a 99 trek 6000 and I have been working on it in my free time. When I try to ride it the back chain keeps going down in the gears until it pops off the gear on my wheel help!!... Read more >>

05/28 Rear Derailleurs

Hi

My rear derailleur is horizontal to the bike frame as opposed to vertical.

I can see no obvious reason for this and am unsure of how to fix it.

The bike was shifting just fine until I literally put it down, picked it back up and went to take off and the rear derailleur had the before mentioned issue.

Any help would be much appreciated.... Read more >>

05/22 7 speed bike / 5 speed shifter handle

So I picked up a newer Schwinn Jaguar off of craigslist for my son.

This is the first bike I've had around in probably 30 years.

The guy I bought it from pointed out that he had replaced the broken stock 7-speed shifter handle with a 5-speed shifter handle. It rides fine and everything else seems to work. The kid wanted it so we brought it home.

I notice that first gear on the shifter is on the third largest sprocket.

Effectively the bike is set up for gears 3-7 at the moment. If I wanted to gear it down is there a way to set it to go from 2-... Read more >>

05/14 Derailleur Spring - how to put it back on?

Hi everyone,

I am very new to bicycle mechanics, trying to get an old mountain bike running better. As I was scrubbing off years of gunk from the chain and derailleur, a piece popped off. I have included pics.

https://onedrive.live.com/redir?resid=9E519F39D9FB9823!1924&authkey=!ACOzLRPoJQNHcCY&v=3&ithint=photo%2cjpg

Read more >>

05/05 Remove chain from front derailleur

I got a Shimano tourney front derailleur on my bike. Need to replace it. How to get the chain out?. I hope, I do not have to break a link on the chain. I see a rivet in one end of the metal. I do not see screw or  bolt tightening the two ends.... Read more >>

04/30 Need to press twice to get to lower clog

I followed the instructions in this video
https://www.youtube.com/watch?v=tfBiXgf8JxI
but I still have the same problem on a Shimano Sora race bike.

With the front derailleur, when I want to switch down from a larger clog to a smaller one, I always have to press the shifter twice: the first time moves the derailleur just a little bit and the second time does the job.

Any hint?... Read more >>

04/09 Change levers to thumb shifters

I have an old 1984 Miyata Model 100
and I plan on replacing the drop handlebar with straight bar.

I'd also like to replace the old lever shifters with thumb shifters on the handlebar. I'm sure this has been done a thousand times but I couldn't find any instructions in this forum.

Any help is appreciated.

Joe

[Image: nzri9x.jpg]... Read more >>

02/29 STI shifter problem

I have one of these old STI shifters from the early 90's

https://drive.google.com/file/d/0By-S838OebDHUnRnSDd2b1dRajQ/view?usp=sharing

I can shift between the center and small chainwheels, but not from the center up to the big one.
The button goes all the way without resistance.

Any way to fix this or is is screwed for good?

Thanks in advance!... Read more >>

01/16 Single-speed to 8x geared conversion shifter problem

Hi all
new to the site; I'm sure this is something that has come up before, but I'm currently trying to do a single-speed to 8x geared conversion, with a downtube shifter.
I've got the dropdown hanger for the rear derailleur bolted into the drop-out (after reading advice from this site...thanks!), and the rear derailleur mounted.

The chain runs through the derailleur and smallest gear (and the front cassette) fine, and I've attached the cable into the derailleur OK. The derailleur adjusts position when I use the shifter, but the chain doesn't move with it. I can manual... Read more >>

01/04 Broken Campy Shifter Help?

Morning!  The shift paddle on my Campagnolo Centaur 10-speed left-side/front lever broke yesterday on my road/commuter bike.  Needless to say, I'm pretty upset with myself, and I'd like to get the bike back on the road ASAP with as little cost as possible.  To that end, a few questions:

1. Can I replace it with any Campy 10-speed lever?  eBay has some Centaurs, but there are a few sets of Chorus levers that are offered at lower prices.

2. Is it worth trying to get repaired?

3. Are there other options I should consider?

Thanks a ton!
... Read more >>

12/26 Failure to shift from 4th to 5th gear

I have a Giant Cypress DX purchased in Sep. 2015.  I am relatively new to bicycling, just started about 2 years ago.  I now little, if anything, about bicycles.  
I recently removed the rear wheel while cleaning the chain and rear cassette.  It was in 3rd gear when I removed the wheel.  When I put the wheel back on I put the chain on the 5th gear instead of the 3rd gear on the cassette(counted in the wrong direction).  I rode the bike and it immediately jumped to 5th gear on the shifter, which is where the chain actually was.  Since then when shifting from 4th to 5th gear it usual... Read more >>

11/24 Shifter/Cable Slack

Hello,

I am having some issues with a SRAM Apex rear shifter and the rear derailleur. I have pulled the shift cable tight and through the holding bolt of the rear derailleur and the barrel adjuster is turned all the way in clockwise. Shifting to easier gears works well, but shifting to the harder gears does not. The shifter clicks but the cable does not stay seated in the spool and remains slack when shifting to harder gears from easier gears ( see picture).
Read more >>

11/15 Derailleurs

Hi I need some help my grandson has messed with  the derailleur on his bike it no longer works and you can only get the pedal to turn a little bit and it jams and wont turn I don't know any think about bikes so I need help to try and fix it for him... Read more >>

New Thread
How to Align a Rear Derailleur Hanger
Repair Guide / Help Forums

Free Email Updates: