Like several other jobs on the bicycle, straightening the handlebar is vexingly subjective. When do you call it good?
The difficulty lies in judging a right angle between the handlebar and the plane of the front wheel as seen from above.
In fact, the eye is better at judging parallelism than squareness. You may have noticed that and tried to align the plane of the front wheel with the stem instead. And that can work fairly well. Still, precision is low because the stem is short … although not short enough to hide an error 50 km from home.
The stem-alignment method works better if you turn the handlebar off-centre to get a clear line of sight to the tyre at both ends of the stem. Like so:
Beware of features on the stem that aren’t quite centred or symmetrical, such as the clamp ears of my Nitto UI-86EX above.
Good enough?
If the handlebar points the wrong way by a smaller angle than can be detected while riding, the problem resides in the theoretical domain. But that’s no comfort to theoretical cyclists.
Periodically someone invents a tool to solve this problem. One example is the Tune Spurtreu. It’s German, like many theoretical problem solvers, so it has a laser for more Exaktheit. As long as your handlebar is round (and free of clutter), the tool self-aligns by gravity and projects a laser pointer onto the front tyre. The goal is to get that red dot onto the tyre’s centreline.
All good, but the Spurtreu has a fundamental weakness: for a given alignment error in degrees, the end of the handlebar moves farther than the red dot on the tyre, since it has a greater radius of rotation about the steering axis. And it is the handlebar ends that are the source of anxiety.
Moreover, the tyre is not an absolute reference point. It’s difficult to be sure that:
the rim is true and correctly dished
the tyre is centred on the rim
the wheel is centred in the drop-outs
the handlebar is perfectly orthogonal to the plane of the wheel
the laser is accurately aligned with the Spurtreu’s frame.
This brings to mind the scenario of hanging a painting with a spirit level or tape measure and then needing to straighten it by eye at the end anyway. Many sources of measurement error and perception error are not obvious to the uninitiated.
Is there a better way?
There’s at least a way with less shopping. And this method, below, exploits the eye’s strength at detecting parallelism while using the length – and therefore precision – of the handlebar.
Start by removing the wheel and setting the bicycle upright on the ground. It will stand on the tines of the fork drop-outs, typically the front tines.
Place a straight object of suitable dimensions, e.g. an aluminium metre rule, on the ground, butting up against the axle-facing sides of the tines that touch the ground. Like this:
The ground in the vicinity of the tines should be flat, so that the rule strikes both tines at the bottom. But even an ancient wooden floor is fine if you avoid the worst planks.
You can guess where this is going. You now have a rule aligned with the axle of the front wheel, against which you can compare the handlebar for parallelism.
(This method requires the drop-outs to be symmetrical, which they usually are for useful purposes. If the rule touched the tines at the height where the axle sits, more than a centimetre off the ground, drop-out symmetry would not matter at all.)
Then stand above the bicycle and close an eye. Sight over the handlebar to bring the edge of the rule close to the edge of the handlebar. The closer the better for accuracy. Things will look like this:
Now compare the gaps between the ruler and handlebar on the left and right sides. They should be equal. Any error is indicated by a doubled difference in gap size, revealing small errors with precision like a dishing gauge does while building wheels.
A closer look at perfection:
You can also sight over other features of the handlebar, such as the ends of the drops. My Nitto Noodle happens to be nearly symmetrical, but some handlebars have a longer drop section on one side than the other. Even a millimetre or two matters.
If the gaps are not the same, fix that by loosening the stem’s clamp on the steerer tube and turning the handlebar. By pushing down on the handlebar while making this adjustment, friction with the ground prevents the fork from moving relative to the rule. With a little coordination you can sight and align at the same time, live. That makes the job a one-step process, avoiding the usual check-adjust-check-adjust rigmarole.
Yes, this method only works if the fork has open drop-outs as Tullio intended. Sorry about that. Maybe you can rig up a 12 mm wooden dowel or something?
Bob Jackson quits
The British frame builder Bob Jackson Cycles will shut shop on 18 December 2020 after 85 years of brazing.
This news will not surprise anyone who has visited their website in the last decade. Still, it’s a loss to those who appreciate brazed-steel frames not for esoteric reasons but because they’re cheap, functional, and reliable. For Bob Jackson frames were cheap, functional, and reliable … and sometimes fairly beautiful, not that you’d guess that from the website.
There used to be a photo of paint colour swatches on that website. It’s gone now, but you can still see it on the Wayback Machine.
When I came across this around 2015, I was shocked (not really) to discover the JPEG was not tagged with an ICC colour profile. That mistake made me doubt the swatches had been photographed suitably (i.e. under daylight-balanced light with a profiled camera), processed suitably (i.e. with colour management throughout), and exported suitably (i.e. in the sRGB colour space).
However, a web browser must assume all of those things to display the colours correctly. Browsers have got better at assuming sRGB for untagged images, and computers (and phones) have started coming from the factory with better profiles, but back in 2015 – or worse, 2002 when the image was first uploaded – that was a lottery.
All of this meant you would have been better off talking about colours down the telephone than looking at this image in Internet Explorer. And no doubt Bob Jackson would have preferred talking on the phone. Tel: 622088.
The world has changed profoundly since Bob Jackson set up shop in 1935. It’s no longer enough for a frame builder to make good frames. Indeed, that may not even be strictly necessary. But a successful frame builder must be good at photography (at least good enough to know when to hire a photographer), graphic design (at least good enough to hire a designer), social media (at least good enough …), Google Ads, YouTube, the trade-show circuit, trend spotting, and more along these lines. Expertise in self-promotion matters more than expertise in the notional field of business. Maybe it’s different if you’re building airliners or bridges, but if you’re building steel bicycles, you gotta hustle.
That’s a change I regret, and one the whole world is slowly coming to regret, but we’re all trapped in its reality. The demise of Bob Jackson proves it.
Bob Jackson’s main competitor in the UK, Mercian, has navigated these new waters slightly better. But Mercian’s prices are more Shoreditch than Leeds. So it goes in the age of shopping.
What is the appropriate response to these trends if not to become a grumpy old man (or woman)? I’m not sure, and get off my lawn.
Bike rides seem to help. They help with other topical anxieties, too.
In other words:
Ride bike!*
Samuel
*Within 1 km of home if you’re in France, as I know some of you are. Ack.