How to Align a Rear Derailleur Hanger
Derailleur hangers are easily bent and can cause shifting problems.
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-2.2 from Park Tool. 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.
Related Links
Recommended Tools
- Park Tool DAG-2.2 Derailleur Hanger Alignment Gauge
- Park Tool AWS-1 3-Way Hex Wrench
- Park Tool AWS-10 Folding Hex Wrench Set
- Park Tool HXS-1.2 Hex Wrench Set
- Park Tool PCS-9 Repair Stand
- Park Tool PCS-4 Repair Stand
Categories
Discuss this topic in the Bicycle Repairs and Mechanics Forum
How can I fuse & wire U7 headlights to Y-splitter connector?
Latest post 5 days agoHi everyone, I wanted to learn how to fuse, connect, or solder two U7 LED headlights into a 1-to-2 Y-splitter. Below are some pics of what they look like. I have an electric kick scooter, and one of the front headlights has blown out. So I am planning to buy two (2) new sets of U7 headlights and a Y-splitter. My idea was to cut off the ends of the 2 female Y-splitters and solder the wires to the ...
Read moreThe Roaming Radrunner Vlog 33: maintenance Matters
Latest post 2 weeks agoHi Folks Please see link to latest Vlog - all about the annual service to my Radrunner - hope you enjoy https://youtu.be/HDKluZTkU20?si=YuGWw-VwpbscVWj6...
Read moreVintage Multi tool
Latest post 2 weeks ago20260119_164440.jpg (Size: 19.36 KB / Downloads: 33) Hi Folks from a very snowy Aberdeen, thank you for letting me join. I have attached a picture of a simple multi tool I picked up with a job lot of bikes/spares can anyone give me info please, date etc 5 1/2 inches long has a screwdriver, tyre lever multi nut spanner and a patch holder ? thanks Les...
Read moreSRAM rival axs index Q
Latest post 2 weeks agoHi there, I recently bought some new wheels for my brand new specialized sl8 expert which runs sram rival axs. Everything is great except gear 12 (smallest cog) is now rejected (red and green LED flashes) in large ring. All other gears run fine. I notice as well that in the large ring it allows me to be in gear 1 which is cross chain? Is that normal? Any ideas what I need to do? Is it a limit sc...
Read moreRear Derailleur Issue
Latest post 3 weeks agoBeen going back and forth adjusting limit screws and tension. 7 Speed. When in the largest cog, the Shimano gear shifter reads 2. The chain will not shift to the smallest cog. When in the 2nd smallest cog, the shifter reads 7. So, no clicks remaining to get to the smallest cog. Any suggestions to resolve the issue. Thanks!...
Read moreTools compatibility
Latest post 3 weeks agoHi there, I'm a new member here....thanks for having me....you look like a nice, friendly and helpful bunch! I've been riding bikes as far back as I can remember, starting on my blue trike with big fat white tyres. I'm now mainly mountain-biking and commuting to work, with a bike for every situation! Over the years I've always done all my own bike maintenance and repairs and recognise now how com...
Read moreSchwinn boundary 29"rear axle
Latest post 4 weeks agoI bought a schwinn boundary 29" and the axle is missing does anyone have or know the size axle i need to get it together?...
Read moreAnyone know how to "fade" paint colors?
Latest post 2 months agoHi to all. I'm wanting to fix up an old MTB and want to use three colors (black for the front, yellow for the mid and red for the rear). I didn't want the colors to just abruptly meet but instead blend into the next. I'm unsure what this technique is called and the net provided no clues. I guessed that it's a "fade" or "blend" technique but it's a mystery how this is done. Can this be done via ...
Read moreHow to refurbish a bicycle 101
Latest post 2 months agoI thought I would do a thread about how to do a quality refurbish on a bicycle that will be a good user trouble free for quite a while. The scope of this refurb will not contain content about dealing with battle scars it may have endured in its lifetime, primarily because the bicycle is merely an example of a solid platform to build from (vintage lugged frame circa 1990). Purchased for $15us ...
Read moreHelp w/Shimano Altus Shift Indicator alignment..
Latest post 2 months agoHi, I have a new 2023 Trek Dual Sport 2 (gen 4) . It has a 2x9 drivetrain with Shimano Altus shifters. The red needle in the shifters window is reading off to the left. In my posted image this is how 5th gear is displayed and 6th gear is actually very close to reading 7th gear and so forth. Is there any way I can adjust this indicator a little bit to the right so it’s properly sitting spot on ...
Read moreWhat can I do if my bike chain keep making lound noises when I switch gears?
Latest post 3 months agoI have an e-bike and every time I switch gears, it makes a loud cranking noise whenever I'm pedaling. Because of this, I normally keep it in gear 6 or 7, and it doesn't make any noise at all. Just only in the initial start-up of pedaling, and then it's fine, but every time I switch it back over to any lower gear or high gear settings, it sounds like it's gonna pop and it makes it loud popping cran...
Read moreCatrike Dumont chamber problem?
Latest post 4 months agoI've read that a bit of negative camber (tops of the wheels tilt inward) is normal for most recumbent trikes, but the Catrike info I've read says that they're supposed to have neutral (0 degree) chamber. After I put two Schwalbe tires on my Catrike, I noticed that the front wheels each have a bit of negative chamber - and that the only causes per Catrike are "If your Catrike Dumont wheels are not...
Read moreChange front wheel to quick release on Schwinn Meridian
Latest post 4 months agoHas anyone replaced the front axle of the Schwinn Meridian trike with a quick release axle/hub? If so, any thoughts/instructions? I am looking at some of the 'replacement' kits on Amazon that are supposed to replace a through axle with a hollow axle that has the quick release skewer inside.... but I don't know anything about them or if they're safe? Or hard to replace? If anyone has any experien...
Read moreQuick release vs. bolt on axle durability
Latest post 4 months agoI'm about to replace the rear wheel on my bike. The new wheel has a quick release, and I'm wondering if, since the axle is hollow, it would make it more prone to bending than the fixed bolt axle. The new wheel is the same brand as the old one (Weinmann 519, 26"x1.5), and they appear identical in all respects except for the axle. My question is, would it be better for the sake of durability to use ...
Read moreEbkarocy 14" Controller Question
Latest post 4 months agoIMG_20251012_124732558_HDR.jpg (Size: 86.29 KB / Downloads: 30) Hi. I recently got this bike and the controller was very loose in the box. I came up with this configuration. Is it ok to have the controller touching the frame like this? Thanks!...
Read more
