As I’ve discussed in previous Debatable articles, I spend a lot of time working on the various bikes that pass through our hands for reviews. I also used to work as a bike mechanic, once upon a time ago, and I can’t help but think that there has to be a better way to address the most irritating, difficult, impossible-to-get-right-the-first-time bike repair task out there (with the possible exception of routing cables internally).
I’m talking, of course, about aligning stems on steerer tubes. Especially with the advent of short stems on mountain bikes, it’s exceedingly hard to do precisely. Long road bike stems are far easier, since you’ve got a much longer stem to sight down, and any misalignment is far more obvious. On modern mountain bikes, though, I absolutely never get it right on the first try, and any time I’m removing a fork or stem or swapping headset spacers around, I invariably need to go through a couple of iterations of riding and re-adjusting before everything is dialed.
I’ll also admit that I don’t know what the right answer is. Making the stem / steerer tube interface keyed might sound like the obvious solution, but I spent enough time working as a mechanical engineer to gain some appreciation for what a tricky manufacturing challenge that would actually be — it’s a lot more complicated than it sounds. For one, making a keyway in the steerer tube without adding a ton of weight isn’t trivial. Neither is making sure that the steerer tube gets pressed in straight so that the keyway is actually aligned correctly. And even if you nail all that, now you have a totally new steerer-stem standard that isn’t compatible with the current parts you have lying around. Surmountable obstacles to be sure, but they would add significant complexity and cost to already not-cheap parts.
And so my best idea is to just laser etch a line up the back of the steerer tube after it’s been assembled into the crown. Granted, that’s another operation that doesn’t need to be done currently, and it would require some fixturing to make sure that line gets put on straight. But it’s a whole lot easier than making a mechanical interface, and wouldn’t require a change to the millions of stems that are already out there in the world — the vast majority already have a pinch bolt slot straight up the back of the stem, which you’d align with my newly-added etched line on the fork. Those that don’t would still work fine, you just wouldn’t get the alignment benefit.
Of course, another solution would be for everyone to just use dual-crown forks and direct mount stems, but that’s got its own, obvious downsides — especially for applications where weight is more of a priority. A Debatable article for another time, perhaps. And so I think my etched line idea is a good one — relatively easy to implement, no real downsides — and I frankly can’t believe I’m giving this one away for free. Fork manufacturers, you’re welcome.
So What Do You Think?
Am I just either cross-eyed or overly OCD about my stem alignment? Or would you like to see that interface improved too? Do you have a better idea of how to go about it? Is there another common bike maintenance task that’s even more annoying? Let us know in the comments.
I worked as a bike mechanic for over 15 years. Aligning a stem? Piece of cake. You know what’s really hard? Getting the rear wheel out, and back in, to change a flat tire, in an old, beat down, dirty, miss-aligned, three-speed type bike, with a threaded cable adjuster for the hub, those weird, narrow axles with flats on them, different bits added to the dropout, and, of course, just the heavy, cheap, unwieldy nature of everything. I also nominate anything to do with gluing and repairing tubular tires. Yuck! What else? Adjusting an old threaded bottom bracket, really adjusting it, so that the fixed cup and lock ring are tight, and the bearings spins freely with no play, which you often can’t tell until you get a crank arm on (!). Hard to get it right the first time. And…I could go on and on. Bike repair: incredibly rewarding, but also extremely frustrating at times.
I’ve never found the job to be harder with a shorter stem because I make the handlebars perpendicular to the front wheel, not the stem perfectly inline with the front wheel.
Unsticking a seat post that’s fused into the seat tube. Impossible.
Line the handlebar up with the fork crown.
I generally find it easiest to go off the arch, but how well that actually works varies a fair bit based on the geometry of the specific fork in question. The RockShox ZEB, with its very straight, boxy arch is great. The newer Fox forks with their rounded arch, less so. Manitou forks with a reverse arch? Pretty much useless.
Diagnosing Shimano hydraulic disc brakes after a crash. I find myself spending hours trying to find the cause of problems. Before COVID I’d have just trashed the brake, but now I’m invariably spending the time because I can’t get parts
Preach.
There are a couple ways to do this, but get a straight rod extending out to the side, parallel to the axle. You can use something like Wolf Tooth’s pack hanger alignment tool or just a plain old rod that fits through the tool socket on the front axle. I’ve even heard of sticking a rod between the spokes and jamming it against the fork legs. It just needs to be parallel to the axle
Then once you’ve got the rod in, use it as a guide to align the bars. Human eyes are absurdly good at seeing whether lines are parallel or not, so if it looks aligned then it is aligned.
I say all this because the actual worst bike maintenance task is road tubeless setup.
Diagnosis of something loose on a full suspension bike: fork bushing play, DU bushing play, bearing play, loose hardware, ext. That job sucks, even more so when doing it solo.
You can buy handlebar alignment jigs if you really want to get it perfect…
DNR Designs makes one if you want, but it would not be hard to fashion your own simple jig. 3 pieces of flat aluminum (or wood) bolted together in a \_/ shape. Snake it through the cables, lay it flat against the fork, and then twist until the bar hits both sides at the same time.
Brakes.
Centering caliper on the rotor. Truing rotors. Bleeding AVIDS. Why are my brand new parts squealing again after 3 rides?
Brakes.
It’s always brakes.
I clicked on this article just so I could tell you that whatever your opinion is, is wrong, and that aligning stems and steer tubes is the worst part of working on bikes right now. You nailed it though! Great article, couldn’t agree more.
I few mentioned the technique above, but I simply sight down the near side of the handlebar to the fork crown. I actually find this method easier and more accurate than aligning a long stem with the front tire, especially with wider tires. Wedging the front wheel against a corner in the garage or shop also allows you to fine tune the stem alignment without front wheel/fork movement. My personal most hated task is full rebuilds of rockshox rear shocks, mostly because it’s something I only do once per year, and it is so tedious. Also bad internal cable routing – never thought string and a vacuum would be necessary just to change cable housing!
To everyone who suggested something other than aligning the stem: all your stems are misaligned, you have bad eyesight and you tend to ride veering off in one direction or another! Just kidding, I hate centering rotors and am currently putting off rebuilding my rockshox rear shock. I was definitely laughing when I read down to find aligning handlebars was the subject here, it is absolutely maddening but I can’t wait to try jamming a rod through the wheel to eyeball the bar.
I’ m a retired Mechanic with may years experience of bike repair.
Without doubt the worst problem I’ve ever had with a MTB, came about whilst building a MTB from scratch. It came as a bare frame with no forks or crank set but it did have a BB fitted., Finding a suitable pedal crank which lined up was a nightmare also finding a suitable front mech took me over a month and a load of money to sort the problem. I decided the bike I had built just wasn’t worth the cost.