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.
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.
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.
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.
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.
- 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
Discuss this topic in the Bicycle Repairs and Mechanics Forum
Hi. I have Shimano HG601 chain 11-speed and I want to add the master link to it. Watched some videos but I have to be 100% sure, that is why I hereby present my brief plan: 1. there is a black link in the chain 2. I use the chain tool to push that black pin out 3. then I add the master link 4. finish up with using the special tongs to press that master link into the chain Does this look like a g...Read more
I just bought some spacers on amazon. Can I take these bars up higher? Right now it’s at seat height, maybe. B244096A-8E83-4716-B335-7FC45A98D0AB.jpeg (Size: 56.94 KB / Downloads: 22) ...Read more
Just out of curiosity; has anyone ever tried using those "super lubricants" in the automotive aisle (e.g. "Slick 50", etc)? Seems I remember a commercial with Al Unser Jr. (or some race car guy) draining their oil from the car and then running around the track at full speed. I am, as an experiment, going try a few drops on a "test" bike just to see how the BB and hubs feel w/o grease. I used to kn...Read more
Hi! Many apologies for my state of panic, but a friendly commenter on Reddit (/r/bikewrench specifically) suggested that I cross-post my question here to see if anyone here could help, so please forgive the rough copy-paste-edit job from my original post there. Basically... with the pandemic going on I recently got a nice custom gravel wheelset built for me using White Industries CLD hubs, which...Read more
My Apollo feud rear gear set was trashed when the bike was loaned ,the click on lock on was damaged how can I fix it please so I can be mobile again.thank you...Read more
Hello! I have a grinding sound coming from my front wheel and I can't figure it out. I took apart the hub and cleaned the ball bearings, which made the wheel spin more smoothly but the sound is still there. I have attached a link to an audio recording of the sound. The sound seems to occur at a slow and steady pace, even when i'm biking pretty fast. I have a single speed bike with rim brakes. any...Read more
Hi. I have a fairly cheepish bike, Appolo Evade Mountain Bike. (The reason for it having a freewheel was probably due to price not age). Anyways. So, there is a tiny bit of freewheel wobble which I have come across on a lot of freewheel bikes so I never considered this a problem. Freewheels just tend to get a little bent right? Despite this, shifting is just fine and smooth and the whole drive ...Read more
I have an original 2010 Trek District 1st edition. I need the rear cog 22t 9 spline replaced, I've stripped out my original one. I can not find this part anywhere and if I go to trek website or even gates, they say the part does not exist. When I contacted gates they informed me that they do not have any and that I could maybe find it through a 3rd party source. I really do not want to change it ...Read more
I'm a former racer attempting to build a business selling bike bleed kits, and I am in this class where we are working on a product/service feasibility assignment. If you're a biker or have some knowledge in the cycling industry, could help me out in taking this quick survey for a business idea of selling bleed kits for bikes, motorcycles, and other vehicles? It involves looking over a one-page ...Read more
Greetings all, Looking for a little advice on why and how to fix the Presta air valve on my Park Tools floor pump. It’s a dual presta Schrader attachment (that in not removable) on the pump and air flow simply stopped flowing into the presta despite lock being on to block Schrader flow. There has been some lead up warning as it became harder to pump and would ‘pop’ when whatever was blocki...Read more
I'm looking for a compatible thumb or bar-end shifter for a Campy 9-speed derailleur. The Jtek ShiftMate 3 looked like the perfect solution as it would allow me to use a cheap Shimano-compatible shifter, but they're only sold by SKS Cycles in the UK and I'd prefer not to ship back to the US from overseas. Does anyone know of other solutions out there (besides friction shifters)?...Read more
All, Just had my brakes replaced and repaired. I noticed that my rear v-brakes were skewed to one side. Not sure how to fix or reconfigure this. Any help is appreciated. The attachment shows the skewed v-brakes leaning to one side. rear-v-brakes.jpg (Size: 57.44 KB / Downloads: 129) Thanks....Read more
I am building my dream bike and I want to put a Chris King bottom bracket in it. It is just very hard to figure out which one is the right one. I plan on getting a Sram DUB crankset because it has the look I´m going for, with a decent price tag. I have a Cinelli Vigorell disc frame. I believe that in order to put the DUB crankset on I would need the King Threadfit 30. I don't know what the differ...Read more
Hi, I followed the park tool instruction for the front and rear derailer alignment but the Front Derailer moves to the bigger cog only when I'm not riding the bike. On the stand, it moves to the bigger cog just fine but whenever I ride it doesn't move. It shifts perfectly on the stand but seems to hit the h limit screw when sitting and actually riding (the cables are not being clamped in any way ...Read more
I've watched the Park Tool video on removing and installing a new crank. I've completed the removal/install and torqued to 45Nm (hoping this is correct for a cheap SR Suntour XCT since I can't find manufacturer guidance). I used a tiny bit of grease (but let's not go down that rabbit hole for this question). Here's where I'm starting to find conflicting info. This document on Sheldon's siteexpla...Read more