The best derailleur hanger alignment tool: 9 tested
Once thought to be only for workshop use, a hanger gauge is now a commonly needed tool to achieve perfect shifting.
Once thought to be only for workshop use, a hanger gauge is now a commonly needed tool to achieve perfect shifting.
Sticking out in the wind, controlling your rear gears and just waiting to be bent, the rear derailleur sits in a precarious position. As a result, it’s the little hanger the derailleur’s bolted to that is commonly designed as a weak point. Best ruin a replaceable piece of aluminium than write off an expensive derailleur, or worse, the frame.
But because derailleur hangers are designed to be sacrificed, that also means they’re prone to bending. That manifests as dodgy and inconsistent shifting that no amount of cable-tension adjusting, limit-screw fiddling or chain cleaning will solve. A derailleur hanger alignment gauge tool is not only extremely useful for diagnosing that your hanger is, in fact, bent, but also for making it straight again.
In this updated version of a feature first published in 2016, we investigate, review, and compare the best options when it comes to derailleur hanger alignment gauge tools.
A hanger tool was previously thought to be a shop-only item, especially as it only requires occasional use. However, as cassette sprocket spacing has become progressively tighter, and frames have become lighter, such a tool has become all the more necessary.
In fact, I’ve worked in shops where the policy was to check every single new bike sold, and any quality bike being serviced. Truthfully, about a third of new bikes straight out of the box would display hanger alignment issues, which were then carefully rectified. Similarly, hanger alignment can be impacted by simple things such as a bike being badly transported in a car, or bumped while awaiting its rider at a café.
Derailleur hanger gauges may seem complex, but their function is quite simple. Typically, the tool threads in place of the rear derailleur to provide a pivoting gauge that is used to measure the distance between the tool arm and the rim of the rear wheel.
As long as the derailleur hanger is tight, the wheel is true, and the hub axle is straight, the hanger tool effectively measures how perpendicular the derailleur hanger is to the rear hub axle. When the gauge is equidistant from the rim at the six, nine, and 12 o’clock positions, the hanger is perfectly aligned.
Using a hanger alignment tool is therefore a matter of lining up the gauge with the rim at the 6 o’clock position, then swinging it up to 12 o’clock. If the gauge doesn’t line up with the rim then the hanger is bent. The arm of the tool provides plenty of leverage for gently “persuading” the hanger back into alignment. Once the 6 and 12 o’clock positions line up, check the 9 o’clock position and bend as needed until these three positions line up evenly with each other, as shown in the sequence below or in this video.
Both Park Tool and Shimano state that a variation of up to 4 mm at the rim (equivalent to ~0.75° deviation from true) is acceptable for properly functioning shifting. Others, such as Jason Quade of Abbey Bike Tools, state that top-tier drivetrains can benefit from being more accurate.
There are a few common things to be wary of when using a hanger tool. First, always make sure the rear wheel is perfectly seated in the dropouts and is tight. Make sure the hanger itself is tight as well. And if your wheel isn’t perfectly true, then simply use the valve stem as a consistent reference point, rotating it around with the derailleur hanger tool’s alignment gauge.
The hanger tool can be used to gently bend the hanger. I’m typically happy to do it as long as the hanger is still in good condition and is attached in a way that won’t damage the frame. Be extremely careful to not overstress the material you’re working with. Aluminium work hardens with repeated bending, meaning it becomes increasingly brittle the more you fiddle with it. If the hanger requires anything more than the gentlest tweak, you’re likely best to replace it entirely – preferably with a high-quality machined unit (from a third party, if necessary) if the stock bit is noticeably soft.
Be cautious of the frame material, too. Some recommend, and most caution against, using a hanger tool with certain carbon frames. If in doubt, check with the frame manufacturer.
Perhaps the most important aspect of any alignment tool is its accuracy, and for hanger tools, the difference between the cheapest and most expensive tools is often obvious due to the amount of lateral play at the pivot point of the tool. The cheapest hanger tools tend to wiggle, making it more difficult to accurately measure the alignment of the hanger. Remember, you’re aiming to be within 4 mm for adequate shifting, so even a small amount of lateral play at the pivot point becomes quite exaggerated at the opposite end, and it can undermine the accuracy of the tool.
Frame clearance is another important aspect to consider, especially if the bikes you’re working on are fitted with racks or fenders. Here the indicator rod of the tool will need to get around these obstructions without losing the setting. Some tools (such as the Park Tool DAG-2.2) achieve this by simply using an O-ring to mark the position, while others (such as the Abbey HAG) can be rotated around such obstructions for faster and more accurate use.
Modern bikes with thru-axles can also challenge the utility of older hanger tools and new designs help overcome such clearance issues. The HAG from Abbey Bike Tools was perhaps the first to address this issue with a longer, narrower tip that can clear virtually every dropout arrangement, while all the other brands tested here have followed with a similar solution (see example in gallery below). I consider open compatibility a critical feature and so tools that are dated in this regard were left out of this test (such as Cyclo and Cyclus).
What’s extremely encouraging is that the newer versions of the tools tested here versus those tested back in 2016 show that tool makers are well aware that the above elements matter. For example, both Park Tool and Lifeline have greatly improved both the accuracy and compatibility of their respective tools.
If you plan to work on smaller-wheeled geared bikes (such as folding bikes or geared kids bikes) then you may want to pay attention to the minimum useable length (listed at the bottom of this article). For example, a 20″ wheeled bike needs a tool that has a minimum useable length down to approximately 200 mm, and so the Abbey HAG and ZTTO HAG won’t work in this case.
It’s also worth noting that such smaller-wheeled bikes typically only have 6-7 gears, and so ‘close enough’ hanger alignment can often be done by eye and without the need for a dedicated tool. It’s mostly newer 10-, 11-, 12- and 13-speed drivetrains that need precise hanger alignment.
There are other issues to consider with a derailleur hanger tool, too. Ease of use is always something to keep in mind. Also be aware of a tool’s size and weight if you intend to travel with it.
It is difficult to judge the accuracy and utility of any tool without putting it to use, so I’ve gathered what I feel are the best and most popular hanger tools that cater to the varying needs (and budgets) of home and professional mechanics. This includes tools from Lifeline, Park Tool, Abbey, Unior, ZTTO, Shimano, and Wolf Tooth.
It’s worth noting that there are a number of other hanger tools on the market, including DIY and low-cost copy options. As noted, a number of the cheaper options suffer from significant play at the bolt (such as some Park Tool knock-offs) or poor frame compatibility as a result of low bolt clearance (such as the well-priced Cyclus and Cyclo hanger tools, or the simplest eBay options). Meanwhile, there are absolutely DIY options that will correctly perform the task of straightening a derailleur hanger, but many of these rely on skilled creation.
The free-play in many of these tools can be mitigated with care by applying consistent pressure to the tool in use, however in reality you’ll always achieve greater accuracy with a tool that offers tighter tolerances and less wiggle – and such a tool also happens to be easier to use. Meanwhile, there’s no great or easy hack for overcoming a tool that lacks clearance to fit on newer style dropouts.
The hanger tools are listed below in order of my preference (most preferable to least).
Based in Bend, Oregon, Abbey Bike Tools creates a limited range of cycling tools that are commonly spotted in the toolboxes of many WorldTour mechanics and ToolBoxWars enthusiasts. Of all tools tested, the HAG is my absolute favourite to use, but of course, such quality comes at a price.
This telescoping tool offers an easy locking indicator rod that freely pivots. The result is a tool that’s quick to use regardless of the bike it’s being used on. Of all the tools tested, it’s the one most obviously built with tolerances that remove all detectable movement and in return, you have absolute confidence over the measured alignment.
It’s built for daily workshop use, but it’s also compact in size and low in weight which makes it a top choice for stashing in a portable tool kit, a tool roll, or where space may otherwise be limited. Abbey has tweaked this tool subtly since I first bought my Abbey HAG some seven years ago (which still functions like new). The latest production version is built with even tighter tolerances than before that stop the body from sliding off under its own weight if left attached to a bike unattended, the head is chamfered to clear the fussiest (worst) of frame fitments, and aesthetically it now wholly matches the asking price.
Yes, this tool will be beyond the budget of many, but excluding the Shimano, it’s so clearly better than the others tested. If you value quality products that last a lifetime, this is the one to get. Just be warned that it won’t work on wheel sizes smaller than 24″.
Highs: Accurate, easy to use, compact, built to last, availability of spares.
Lows: Price, too long to fit smaller-wheeled bikes.
Price: US$185 / €185 / AU$317
Manufacturer page: abbeybiketools.com
There’s arguably no hanger tool more commonly owned and used (and copied) than Park Tool’s DAG series. Over recent decades the form factor of this tool hasn’t changed, but Park has steadily increased the operating tolerances and dropout compatibility. The most recent update is the DAG-2.2.
This tool continues to do everything it needs to and does it without fuss. The somewhat agricultural build is solid and reliable, and it’s certainly up to bending whatever dropout you dare.
It’s worth noting that it lacks a quick pivot or similar feature for the secured indicator rod. It does also have some measurable movement at the head (1.1 mm), and it’s not all that friendly to storing in a portable or compact toolbox. Still, this is a safe purchase for many and is what I’d suggest for those needing a reliable workshop tool and who can’t justify something like the Abbey HAG.
As a final note, Park Tool offers solid warranty and service parts support of older products. I personally think that justifies the higher asking price of this over cheaper copy versions.
Highs: Price, no-nonsense build, fairly easy to use, availability of spares.
Lows: Does not pivot around obstructions, average accuracy, not compact.
Price: US$80 / €80 / AU$150 (often found for less)
Manufacturer page: parktool.com
Lifeline is the house brand of Wiggle/CRC, and many of the company’s tools can often be found under other names, too. In this case, the Lifeline Hanger tool is almost identical to the SuperB hanger tool (the likely manufacturer, too).
I was quite pleased to get my hands on the latest version of this tool and see its development progress from when I last reviewed it in 2016. The new version no longer suffers from limited hanger compatibility and the tolerances have been greatly improved, too.
Overall the functions (and limitations) of this tool are closely comparable to the Park Tool DAG-2.2, albeit with slightly more measurable movement (1.5 mm) in the head that will impact its absolute accuracy. Likewise, the indicator rod, while pretty secure in use, isn’t physically locked and so accidentally bumping it against the rim or tyre will require you to restart your alignment.
Still, for many home mechanics, this tool (or the SuperB equivalent) remains an affordable and perfectly adequate option and is exactly what I’d suggest for those unable to stretch for the Park Tool DAG-2.2. Just beware that long-term availability of service parts for this tool is unlikely, something the Park clearly has it beat at.
Highs: Price, no-nonsense build, fairly easy to use, availability of spares.
Lows: Does not pivot, so-so accuracy, not compact.
Price: US$67 / €48 / AU$93 (often found for less)
Manufacturer page: wiggle.com
The Shimano TL-RD11 is rarely seen, and yet, its function is quite brilliant. The design is closely comparable to the Abbey HAG but the Shimano tool is built with a keyed telescoping design and a pivoting indicator rod that locks into a consistent square position via a detent ball. This clever pivoting indicator design is licensed from Efficient Velo Tools.
The indicator rod is in fact a small steel ruler, and while it doesn’t lock in place, it’s held securely enough to be confident that you haven’t accidentally changed its position. However, some care is needed to not scratch rims with it.
Overall the tool is an impressive mix of a solid build, compact sizing, and ease of use. Keeping in mind that the sample I tested had a hard life prior to my trial, it, unfortunately, did still exhibit some noticeable play (something that isn’t the case with my seven-year-old Abbey). Add in that the tool isn’t quite as compact to store or as easy to source replacement parts for as the similarly priced Abbey, and my choice for the overall best option remains with the green one.
I’d happily own one of these, but only if the price was noticeably better than the Abbey HAG.
Highs: Easy to use, fair accuracy, built to last.
Lows: Price, needs minor disassembly for compact storage, worn sample exhibited some play.
Price: US$300 / €200 / AU$310
Manufacturer page: N/A
A new addition to Park Tool’s extensive range, the DAG-3 is designed as the premium version of the widely used DAG-2.2. The intended benefits of this tool include a noticeably improved build quality, smoother operation, and an indicator rod that pivots out of the way to get around fenders and frame tubes. And in measuring the play in the tool, the DAG-3 finished a close second behind the Abbey Bike Tools.
Overall this new hanger tool works well but I personally didn’t get on with the new indicator rod design that uses small wave springs to hold it in place. Here the tool lacks the ability to lock the indicator rod setting in place and I often found myself accidentally touching the indicator rod to the wheel’s rim and then losing my starting position. As a result I’d have to start the alignment process again.
The Lifeline Pro hanger tool exhibits the same issue, but the Park DAG-3 is worse due to even lower spring tension. This will become a truly great option if Park adds the ability to lock the indicator rod.
Highs: Accurate, pivoting design, availability of spares, handle end caps can be replaced with any Schrader valve cap (fun).
Lows: Indicator rod cannot be locked and makes tool fiddlier to use, not compact.
Price: US$117 / €TBC / AU$200
Manufacturer page: parktool.com
Search for bike parts, tools, or accessories on AliExpress, eBay, or Amazon and you’ll most likely come across ZTTO on the first page of results. This low-cost hanger tool clearly takes inspiration from the Abbey HAG, but its design is actually noticeably different (worse).
The predominately aluminium tool offers a keyed telescoping design, while the removable indicator rod is free to swivel at the end of the tool. This tool is impressively lightweight and cheap, but it suffers from some fairly major design flaws. For example, while the head is fairly free of movement, the keyed telescoping design isn’t and the play gets noticeably poorer once extended out to reach a 700C/29er rim.
Similarly, the indicator rod can’t be locked into place and instead relies on o-rings for keeping the measurement. You’ll certainly want to be triple-checking your measurement prior to making any bends with this one. And similar to the Abbey HAG, the minimum useable length of this tool means it’s no good for smaller-wheeled bikes.
The pricing of this Abbey lookalike is no doubt attractive, but the indicator rod needs to be more securely held before I can recommend this tool to anyone. Skilled makers will be able to drill/tap a screw in to fix this very issue, but you shouldn’t need to modify a new purchase to make it work.
Highs: Price, portability, pivoting design.
Lows: Accuracy, indicator rod sits loosely and can’t be locked, availability of spares, won’t fit smaller-wheeled bikes.
Price: US$52 / €49 / AU$75
Manufacturer page: AliExpress.com
The Unior Hanger Genie arrived on the scene a couple of years after the Abbey HAG and clearly displays some similarities. The tool is compact, it offers an indicator rod that can be both locked into its setting and rotated around obstructions, and it’s built to take a knock.
Sadly, in use, the Unior simply feels like a less refined version of the Abbey HAG. Compared to any other tool on the test, my sample suffers from the most amount of movement at the head (which can’t be adjusted) and therefore lacks confident accuracy. Meanwhile, the sliding surfaces aren’t all that smooth, and the steel construction is prone to surface corrosion.
And to add to those issues, the Unior’s limited telescoping range means the tool comes with a second offset indicator rod to work with extremely small or big wheels. It’s an addition that honestly just feels like an afterthought.
Unior makes a number of professional-quality tools but this one, unfortunately, falls short. There is still a decent amount to like in this tool, but fundamentally the price is too high given the tolerances don’t allow for benchmark alignment accuracy.
Highs: Compact size, easy to use, pivoting design, indicator rod can be locked in place.
Lows: Poor tolerances impact accuracy, susceptible to corrosion, price.
Price: US$130 / €90 / AU$220
Manufacturer page: uniortools.com
Wolf Tooth’s approach to hanger alignment is like no other. Designed to be rugged, lightweight, and packable, this hanger tool is a part of Wolf Tooth’s clever Pack Tools range. And unlike all the others covered above, this hanger tool doesn’t use the rim as a reference point for squareness but rather uses two parallel rods at the axle.
Our previous coverage of this unique hanger tool shows the function: you thread a large rod in place of your rear derailleur and then replace your thru-axle (or the end cap of your quick-release skewer) with the second rod. Wolf Tooth offer fitments for the three most common thru-axle thread pitches and the tool is impressively packaged together in a wonderfully compact and high-quality assembly.
Functionally the tool solves common issues such as concerns over axle or rim straightness, compatibility with both big and small wheels, and it also suffers no measurement wiggle. But the design introduces other issues such as requiring a keen eye to achieve perfect hanger straightness, it can be slower to use if you need to adjust it between multiple bikes, and then it simply can’t be used at all on some closed dropout designs (e.g. many Canyon bikes and the new BMC SLR01). Those intrigued by the simplicity of the design should also check out this DIY version.
I truly questioned the low placing of this tool in this test, especially given how well made it is. Perhaps straightening derailleur hangers one way for nearly two decades has caused some bias over how I think the task is best done. I personally found this tool slower and harder to use, but those coming to the task with fresh eyes may have a different opinion.
Highs: Intriguing design, lowest weight, no play or wheel issues to throw-off alignment, availability of spares.
Lows: Fiddlier to set up, requires a careful eye for accuracy, won’t fit certain frames with closed dropout ends or weird axle thread pitches.
Price: US$120 / €125 / AU$190
Manufacturer page: wolftoothcomponents.com
A sibling of the Tune Spurtreu stem alignment tool, this laser-based tool is less of a hanger alignment tool and more something designed to assist with aligning your derailleur limits and cable (or electronic) tension. It simply works by sticking the tooled bit into your derailleur and aligning the laser straight to the chain on the cassette – from there (at least in theory), the laser should show you where the centre of derailleur pulleys should sit.
Admittedly I bought this tool in the hope of it being a quick way to diagnose bent derailleurs/hangers, something it doesn’t do so well. And similarly, it’s most certainly not intended to be used for bending a bent derailleur back to parallel. So while it doesn’t truly belong in this test, I thought I’d include it just in case you were thinking of buying it over the options above.
Even when used for its intended purpose it has some significant issues. Just stick a hex key into the mounting bolt of your rear derailleur and you’ll likely have some wiggle in the tool interface – now pretend you have a laser mounted to the opposite end of this hex key while it is wobbling – not exactly precise, is it?
I also found it far more time consuming to dial in the tool than to adjust the derailleur by ear or eye. And on more than a few derailleurs I couldn’t get the tool with its stock short bits to fit. And then you need to deal with tiny precision-sized screws to solve that. I could go on, but I’ve already used too many words on a tool that won’t help you correctly diagnose a bent hanger nor fix one.
There’s no denying this thing is impressive to look at with its lush green anodising over an intricate machined tool. And who doesn’t like lasers? But I simply did not get on with this tool and wholeheartedly cannot recommend anyone buys one (unless you want to buy mine. Just joking. But also not).
Highs: Works with derailleur in place, lasers are cool.
Lows: Almost useless for diagnosing hanger alignment, reliant on derailleur bolt tolerance, delicate, fiddly to use.
Price: US$200 / €130 / AU$250
Manufacturer page: tune.de
While I stand by the choices above for both the home user and professional mechanic, there are other even more premium options. The most notable one is from E.V.T, which arguably stands as the very finest available provided cost, weight, cost, storage space, and cost are of no concern. Did I mention it’s US$600 and with limited supply?
Meanwhile, many veteran mechanics will swear by the classic Campagnolo hanger tool. While I can’t deny its function on a classic road bike, it certainly lacks the wide bike/frame compatibility and ease of accuracy found in the latest tools tested. It’s for these reasons it was omitted from this shootout; likewise for the well-priced tools from Cyclo and Cyclus.
Got a hanger tool that’s served you well? How about a DIY hack that gets the job done? Let us know in the comments below.