Abbey Bike Tools Hanger Alignment Gauge Tool

The Abbey Bike Tools Hanger Alignment Gauge (HAG) is a stupendously accurate (and commensurately expensive) way to ensure your rear mech is given the best possible chance of achieving shifting nirvana. Relatively small, light and rebuildable, it really is 'The last hanger tool you'll ever have to buy'.

• Pros: NASA-grade accuracy, light, compact, rebuildable, used by the pros
• Cons: Price, practice needed to perfect measurement, won't do 20in or smaller wheels, you won't want to put it in your toolbox and it's likely to get nicked from a shadowboard

The motto of Abbey Bike Tools is 'Precision is our religion'. Owned and operated by Jason 'The Friar' Quade, the Abbey name stems from a love of the spiritual home of cycling, Belgium, and its indescribably good beers. Bend, Oregon is where Abbey started in 2010 and is still based today.

> Buy this online here

Let's get something out of the way first: the price. It's One Hundred And Seventy British Pounds, for something with five parts that is ostensibly a stick to bend your derailleur hanger with. Those of a nature that upon reading such a description find their pulses racing with indignation can turn to the latest Aldi catalogue, I'm sure there's a bike tool special buy due any day now. This will not be the review for you.

Let's set the scene for the HAG, because beginnings are very delicate times. The ethos of Abbey Bike Tools reads thus:

'We design new tools without concern for the final price. This doesn't mean we aim to build expensive tools. Rather, we aren't willing to cut corners in the name of price. This is the reason that we have such a loyal following among professional race mechanics across all disciplines and around the world. When time matters and results pay the bills there's only one tool company that you want in your hand, sponsors be damned'.

And just as pro teams will use tyres from non-sponsors with logos Magic-Marker'd out, pro mechanics will use whatever they think will do the job best – 'sponsors be damned'. In many drivetrain cases, that tool is the HAG – but not just any HAG. From time to time The Friar goes all-out with a titanium version – it's 160 hand luggage-friendly grams lighter than the steel version and costs $325, with custom engraving and, one assumes, its own green velvet cushion included.

But we digress.

Small is good

Physically the HAG is smaller than any other hanger tool – for good reason. This is a pro tool, designed to be carried in toolboxes onto planes by pro mechanics. So every gram and millimetre is critical, as is the ability to rebuild if worn or damaged. As the measurement point is at the end of the arm, there's an inherent limitation to the size of wheel you can measure, in this case nothing smaller than 24in. But hey – this is a pro tool and the use case isn't truing Bromptons or kids' bikes.

A good frame of reference at this point would be the alternative, and that's really the £63 Park Tool DAG-2.2. Since reviewing the 2.2 a few years back, I've owned one and used it hundreds of times on my own and customers' bikes. As reviewed, it's fine – I stand by my assertion that it will meet the needs of all but the pickiest of home mechanics. As I highlighted in the review, you need to shift the measuring arm out of the way and use the rubber gauge every time – which, as you'll see, is a step and possible inaccuracy the HAG does away with.

The premise of the HAG, as with any hanger tool, is thus: remove mech, screw tool into hanger, spin wheel so valve is at 12, 3, 6 and 9 o-clock as viewed from the drive side, and check at each point that the 'gauge' rod is just touching the valve. That's it.

When you find that at 180-degree opposite points the gauge reads closer or further away, you use the arm of the tool to carefully bend the hanger, so that on a repeat of measuring everything's equidistant. This may well take three or four goes to get it just right, necessitating repeated movement of the gauge as needed. Once done in, say, the vertical plane, repeat for the horizontal. Then check that the subsequent adjustment didn't muck up the first one – so as you can sense, there's a fair bit of back-and-forth.

Chainstays, seatstays, racks and mudguards complicate this process by getting in the way, necessitating a fair bit of faff if the measuring rod needs sliding and locking – as the DAG-2.2 does. And if you knock the little rubber ring gauge, start all over.

The part of the HAG that screws into the hanger is functionally the same as the DAG-2.2, but the execution is exquisite. The first turn of the T-handle inside its replaceable brass bushing tells your fingers that this is special – the threads engage with a silken action that I've rarely felt on any tool, bike or otherwise. The precision is such that when tight, the T-handle stops dead – no play, no ability to force it further belying a slightly sub-perfect thread cut.

Once screwed in place the HAG is free to spin on the hanger, and the measuring begins. The green alloy body can slide in and out and rotate freely. At its head is a threaded cap, with the actual measuring rod stored inside. The rod is removed, and inserted at 90 degrees through the cap. The body then screws further into the cap, locking the measuring rod in place, and allowing the whole setup to move in and out and spin.

Genius

This is the genius of the HAG – once you've set the first measurement, it is very quick and one-handed to spin and shift the tool around the stays to measure further points while the other hand rotates and holds the tyre. If an adjustment is needed, the rod can be easily shifted and resecured, which is a two-handed operation.

My only gripe – if you can call it that – with the HAG is that if you let it swing down and let go, then sometimes over a dozen or so seconds the body will slide off the bit that's threaded to the bike and end up on the floor. Does it need some sort of stop, or should the expectation be that if you've invested £170 in such a tool you are 100 per cent focused on its use and care? Either way, the fact that it takes that long to slide apart gives you a hint at the tolerances (down to 0.0063mm) the parts are machined to.

The Shimano derailleur hanger specification allows for less than +/- 4mm deviation as measured at the rim. Your rear mech's top jockey wheel feeds the chain onto your sprocket at a radius of between 30 and 50mm from the mech hanger (as viewed from the side), depending on what gear you're in. So that 4mm maximum hanger deviation spec at the rim 300mm away translates into a possible 0.4-0.8mm departure from vertical at the jockey wheel.

This might sound like a tiny amount, but if you have an 11-speed cassette, the clearance between the chain’s outer plates and the neighbouring sprockets' teeth either side is about 0.13mm. So you can see how a jockey wheel out of place by 0.4-0.8mm when your chain only clears the neighbouring sprockets by 0.13mm can lead to shifting problems. The issue being, the error of 0.4mm in your smallest sprocket is amplified to 0.8mm at your largest sprocket as you shift across.

This is why, if your hanger is bent, you can index the smaller sprockets fine but the shifting goes to pot as you move up the cassette. Jockey wheels have side-to-side play built into them to try to accommodate these tight tolerances, but if the hanger's bent the increasingly-wider gap can't be taken up.

At 90rpm in a 50T chainring your chain is contacting new sprocket teeth off the derailleur jockey wheel at a rate of about 75 links per second. And you're likely putting 200 watts plus through it, if you're going for it. Frankly I'm amazed bicycles work at all, but again I digress.

Measuring the valve gap on my good bike with the DAG-2.2 I got about 2mm, which was pretty good I thought. Historically if it were that close I usually stopped there. Measured with the HAG, the gap was 1.5mm – but with no reference ring like on the 2.2 I had to use a feeler gauge to confirm.

Aside from measurement, the other role of the HAG is brute force bending, to adjust the hanger. With zero play in the body or thread, this felt tighter and more controlled than with the DAG-2.2, meaning adjustments were made quicker and with less to-and-fro and repeated bending likely to lead to a stress fracture in the future.

After a bit of fettling I was able to get the variance down to about 1.15mm difference between the HAG and DAG-2.2. But there the DAG-2.2 ran up against its inherent lack of precision – in addition to the 1mm or so of play in the main bushing, spinning between measurement points the DAG-2.2 wouldn't true completely, leading me to suspect something in the geometry of the threaded section was out, thereby condemning it to forever swing in an arc out of true with the wheel itself.

Using the HAG, my hanger aligned perfectly, referencing all the way around the wheel. And I mean perfectly – like, no space for any of my automotive feeler gauges to fit betwixt rod and valve. I got to slowly spinning the body back and forth with the rod merely scraping the valve stem, more barely-audible than tactile, to confirm the contact.

Purr-fect

The proof's out there on the road, and the HAG's work gave me a sound from the Shimano Ultegra groupset I've never heard before, but easily detected on new smooth tarmac – I can only describe it as 'purring'. After you've put many thousands of miles into a bike you become acutely attuned to changes in sound and feel, and that's what I picked up after aligning things with the HAG – the experience of shifting and pedalling was notably quieter and slicker.

I had the same experience aligning my turbo trainer bike's Microshift 11-speed groupset: quieter, tighter, across the whole cassette.

For what it's worth…

Now £170 is indeed a pretty penny to spend for 'tighter' and 'quieter', and here's the nub of the HAG-vs-DAG debate: is it *worth* an extra £110? As with so many things bike, that depends entirely on your optics – where you sit re budget, precision, size, weight, performance, design and so on. If you're on a limited budget and need to get your bike functional, the DAG-2.2 will do the job just fine, and more power to you.

> Beginner's guide to bike tools

I asked Mark Legg, pro mechanic and husband of cyclo-cross star Katie Compton, for his thoughts on the HAG: 'I've bought two of them. One for the US and one for Belgium. Functionally they are fantastic to use. I often keep one in my pit bag for CX. I love the craftsmanship of the HAG. Definitely a must have tool to own for the races or the workshop.'

So yes, you can get close to perfect for one third the cash. But if you're working at the pointy end of cycle racing, frequently bend bikes while travelling, are after a psychological boost from knowing your ride is as tight as it can be, or maybe you're just a fan of exquisite engineering and the beauty of a near-perfect tool, the Abbey Bike Tools HAG might be one for your Significant Birthday wish list.

Verdict

The last word in derailleur alignment precision: a tool you'll love for life