Jim’s Tech Talk
By Jim Langley
Rating: 
Hot
Game-changing derailleur hanger alignment
Easy to use – sight across rods then adjust hanger until rods are parallel
More accurate alignment
Affordable
Small and light to take along as a ride-saver
Not
None
Price: Quick Release Kit: $59.95; Thru Axle Kit: $99.95; Quick Release and Thru Axle Kit: $119.95
Weight: Quick Release Kit: 175 grams; Thru Axle Kit: 297 grams; Quick Release and Thru Axle Kit: 324 grams
Materials: 7075-T6/6061-T6 aluminum and 303 stainless steel
Made in the USA
Compatibility:
Frames with standard M10x1 threaded derailleur hangers
Frames with 12mm thru axles or 5mm quick releases
Frame spacing: Quick release: all widths; Thru axle: 12×142 to 12×197
How obtained: Company sample
RBR advertiser: No
A Brilliant New Tool for Aligning Bent Derailleur Hangers
I think this new derailleur hanger aligner from Wolf Tooth is one of the most impressive cycling inventions to come along in years. It’s a completely new take on a tool that’s been around – essentially in the same form, for at least 60 years, maybe even longer.
And here’s the thing, that old tool became the only tool available for the job. Lots of companies have made improvements over the decades (since 1971, I’ve owned five of them). Yet no matter which one you used – it was always a difficult tool to operate and it didn’t align hangers very accurately as a result. In the photo the two tools on top are of the old design and Wolf Tooth’s is at the bottom.
That’s why it’s so exciting to see Wolf Tooth’s ingenious solution. Unlike the old standard tools, theirs is easier to use, makes more accurate adjustments, is only $59.95 for the quick release kit ($99.95 or thru-axle), and is even small enough to fit in a pack and take along on rides. I like it so much I’m giving it 5 stars, our highest rating.
Perfect Timing
A better mousetrap for derailleur hanger straightening and alignment couldn’t have come along at a more appropriate time. Now that our bikes have tightly spaced 10-, 11-,and 12-speed drivetrains, it’s essential for rear derailleurs to be properly aligned to the rear cassette for crisp, consistent shifting. Perfect alignment is even more important with electronic drivetrains that rely on exact steps of a motor for each shift (versus cables that develop play).
Yet, just when it’s so important to have perfect hanger alignment, the majority of bicycles today come with easily bent aluminum derailleur hangers. Something as seemingly harmless as your bike falling over can result in the rear derailleur hitting the ground (or if the bike itself falls over, such as when it’s precariously parked). Crashing and hitting the derailleur will bend the hanger worse, as can getting something stuck in the derailleur.
What’s more, lots of roadies are discovering the dirt, and long gravel rides. Meanwhile, touring, randonneuring and bike camping are becoming popular again. These types of riding increase the chances of bike-dropping, crashing and bending a derailleur hanger. So Wolf Tooth making a pro tool that actually works and gets small enough to carry is genius (all the pieces fit inside the handle).
Is a bent derailleur hanger that big a deal?
Whether or not you should worry about a bent hanger depends on how badly bent it is. Sometimes it’s bent even on a new bike, and you may not notice the occasional shifting hiccup or a bit more noise than there should be. But ideally, your bike wouldn’t have these issues and straightening the hanger would fix them.
With worse bends, you also might not realize anything’s wrong. But in that case, the hanger is badly bent and now angled in too close to the rear wheel. This usually causes shifting into the spokes. If you’ll pardon the pun, that can create a chain reaction, the rear derailleur diving into the spokes, getting mangled by them and probably tearing some of them out. Obviously you want to avoid this.
Hangers are supposed to bend
The ironic thing is that because the derailleur is so much longer than the hanger and can exert so much leverage on it, hangers are actually designed to bend so that they don’t break. That design originated with steel frames on which a broken hanger might require a difficult and costly repair (replacing the entire dropout plus repainting).
Today’s mostly aluminum hangers are almost always replaceable, but you still don’t want to risk breaking them. Because it might ruin the attachment point, which could wreck the frame.
All these reasons are why I think a lot of roadies would like to own a hanger alignment tool, and especially one as revolutionary and easy to use as Wolf Tooth’s.
Using Wolf Tooth’s Aligner
Because this new tool checks alignment by referencing the rear axle (instead of the rear rim like all previous designs), Wolf Tooth has two kits. One is for bikes with quick-release axles, and one is for thru-axle bikes (you can purchase a combined kit and you can upgrade a thru-axle kit to add the quick-release option, too).
Whichever axle type you have, when the Wolf Tooth kit is in place on the bike, it gives you two protruding rods. One extends from the rear axle and is fixed in position for reference. The other rod extends from the hole in the derailleur hanger (you remove the derailleur first).
Once the two rods are in place, you’re ready to both check the alignment and fix any issues. To check, you simply sight from all angles and ensure that the two rods are always parallel to each other. If so, you’re good to go – nothing to straighten or fix.
If the hanger is bent like the one in the photo, it’s easy to see. And to align the hanger just takes gently pressing on the hanger rod until it is parallel to the fixed axle rod. You sight from every direction and keep fine tuning until you see parallel lines looking across both rods.
This is much easier than the way it’s done with all the “old” conventional hanger alignment tools, which use multiple reference points on the rim. And, comparing my results with both tools, Wolf Tooth’s better mousetrap gets more accurate results. That’s the most important part and why I’m err.. howling with excitement over Wolf Tooth’s terrific new tool.
Comparison of Wolf Tooth’s and a convention hanger alignment tool
In this video, I show how both tools work to demonstrate why I think this new design is such a game-changer.
For step-by-step video instructions on tool setup and use, watch Wolf Tooth’s videos:
Quick Release: https://www.youtube.com/watch?v=IpWoySCg0BA
Thru-Axle: https://www.youtube.com/watch?v=Kd66PAulUR0
Ride total: 9,310
This sounds like a terrific tool to have, particularly on the road with you. One thought though, carry a spare hanger with you, either in your bag or taped under your saddle. It seems like it might be easy to go “GODZILLA” with this tool and break an already weakened hanger particularly while stressed on the trail.
You can always count on Wolf Tooth to come out with another innovative quality tool! I have their rear derailleur (RD) roadlink dropper which allows you to go to a larger cassette without having to change to a longer cage RD. Brilliant. I also have transformed my ULTEGRA 6800 equipped Giant TCR Advanced into a 1x gravel bike using a Wolf Tooth 110 bcd asymmetric 4-bolt chain ring with an 11-46 XT cassette. In order to get this gearing to work, I swapped out the ULTEGRA RD for a long cage XT RD. Since they have different shifting
pull, I added a Wolf Tooth Tanpan which converts the ULTEGRA shift pull to an XT/XT shift pull. Everything works flawlessly. I highly recommend Wolf Tooth for any special projects and/or replacement parts. Top Notch Quality!
JPS, Jim, when you are done with your alignment tool, send it my way!
RIck
That’s slick! I love my Abbey alignment tool, but I’m going to get one of these to take on my trips as my Marinoni hanger bends very easily.
Thanks
(Bryan, read my reply below)
The RD mounts to the hanger with a 10x1mm bolt, which is the same thread as a typical threaded rear axle (e.g., Shimano). So an old method, in the absence of a fancy alignment gauge, was to screw a spare axle into the hanger and eyeball it for alignment. Seems like Wolf Tooth has taken an old concept and done a very nice job of making a new, improved version.
This tool looks smart, and I’m sure it produces a result with less fiddling about. I have a Park Tool aligner, and it always takes several iterations before I’m happy. But .. I am wondering upon what basis you say it produces ‘more accurate’ alignment? Have you conducted a shoot out?
Thanks, Don. Yes, I compared the results of using a standard tool and using Wolf Tooth’s new hanger alignment tool and Wolf Tooth’s was both easier to use and more accurate. This is apparent as soon as you use the new tool. I tried to show this in the video in case you missed that.
But to explain, with the “old” tools, you are trying to take a measurement with a moving pointer/indicator. Yes, you can set the indicator at each point where you take the measurement at the rim. However, because the hanger hole is not at the same height as the axle, you have to keep moving the indicator’s holder up and down so that the indicator is at the same height as the rim.
You also have to move the indicator so it doesn’t hit the seatstays or chainstays. These adjustments to the indicator make it difficult to get truly accurate measurements. Shimano made an alignment tool that had a ruler as the indicator – see it here – .https://tinyurl.com/y6tmcy4f but even that tool didn’t make it easy to get accurate measurements.
When you use Wolf Tooth’s tool it’s a no-brainer comparison of 2 parallel lines formed by the 2 rods extending from the hanger and axle. You don’t have to move tools, worry about whether the rim is straight or not, or measure anything. And, you are looking at indicators that are right next to each other, they might even be touching with a badly bent hanger. This is very different from the old tool where your point of reference is far away from the hanger and on a line 90 degrees to the hanger not in line with it the way Wolf Tooth’s is.
You will see straight away with Wolf Tooth’s tool if the hanger needs aligning or not. And then to align the hanger you will love how accurately you can fine tune the hanger’s position with the straight rod attached to it, versus the old tool’s long arm attached to the side of the hanger.
If you get to give Wolf Tooth’s tool a try I’m willing to bet your old tool becomes a dust collector. Hope I explained. Let me know if there are more questions.
In cycling,
Jim Langley
I thought most, if not all frames today come with a replaceable derailleur hanger? I know all my frames have them. I do know that it is risky bending a replaceable hanger and most manufactures of said hangers strongly recommend not re-aligning them. I just carry a spare hanger in my rattle bag and it’s a quick easy fix on the road or trail. Been doing this for years and it is really needed mostly on long all day MTB rides as rocks and roots seem to just jump out and grab that derailleur. And with the newer derailleurs that sit under the chain stay and help protect it from damage I think carrying a alignment tool on every ride is kind of over doing it a bit. In my 30+ years years I’ve not see too many riders break or bend a rear hanger, and if you hit hard enough the hanger is meant to break instead of damaging the derailleur so you’ll need a replacement hanger anyway.
Thanks for the feedback, Kenneth. Yes, most modern bikes have replaceable derailleur hangers, yet when a hanger gets bent you never know if the replacement hanger is aligned perfectly or not because whatever bent the old hanger could have damaged more than the hanger. So, it’s always smart to check the alignment even with replacement hangers once they are in place on the frame.
Hangers are the Achilles heel of the bicycle. It’s great that companies are trying to save the hanger with improved derailleurs. But there are millions of bicycles out there in use and not all new bikes with replaceable hangers or the latest derailleur designs. So, I’m sure Wolf Tooth’s new packable tool will be popular with many riders who like to be equipped to help friends on rides with whatever goes wrong with their bikes. But, it’s definitely a good idea to carry a replacement hanger for your bike if it takes one.
Thanks,
Jim
My first three bikes did not have them and my Shimano TL-010 worked very well on them. I think too, that when steel was falling out of favor for aluminum that the alloy was too brittle for the repeated bending and torque of regular hanger alignment so they came out with the replaceable hanger. I must admit that I do re-align replaceable hangers on mine and friends rides if they aren’t bent too badly. I know when I first started riding I felt like I had to carry every tool that may be needed for a trailside repair. But as my wrenching became better my need for certain tools declined. I trusted my maintenance and now I’m a minimalist. Tube, tire lever, glueless patches and a 4 and 5mm wrenches. I try to make sure all significant bolts are either 4 or 5mm so I don’t need to carry a multitool. 6mm is all but dead, I think…. I’m strictly road now so I don’t know what’s happening in the MTB world. I’m all for carrying tools needed on rides but I also weigh the odds of needing that tool on any particular ride. If I’m staying within 50miles I’ll go light, I can always call a cab or friend. If its a solo all-day affair then it’s a chain tool and compact spoke wrench. I think experience and learning from mine and others mistakes is the best teacher, and it makes cycling so much more fun for me, and the group, And it ‘s great for your confidence too!
Thanks, Kenneth. Yes, it is great for your confidence. Excellent point!
Jim
I see the derailleur hanger as a sacrificial component, that is it’s designed to deform and possibly save the derailleur itself from damage. So if it’s the Achilles heel of a bicycle, that’s by design. And it’s meant be be deformed back again, ie straightened.
Jim: I bought the Wolf Tooth derailleur hanger tool on your recommendation and, many months of use later, I am happy to report that its ease of use and accuracy are exactly as you described. It has replaced the EVT tool in my home shop and the Abbey tool in my travel kit. In the shop, the distance between the two tubes can be even be checked with a vernier caliper!
Thanks again for your consistently outstanding tech advice!
Dan R.
This tool is not precise enough to work with my 12 speed Campy groupset. Not even close! I finally broke down and bought the Abbey Bike Tools HAG, and was blown away at how off my previous adjustments had been having used the Wolf Tooth tool…and I was using a digital caliper and magnifying glasses with the Wolf Tooth to get the measurements exact (down to 1/1000 of an inch!) . . . so you know.