islandix.com
I'm a bicycle mechanic that figured I could make the process of bicycle wheelbuilding faster, more accurate and more satisfying. I do it by sampling digital indicators, rendering the data in useful ways, and injecting domain-specific insights. The UI interaction happens by foot pedal so my paradigm retains the traditional way of working with your hands.
I think for most people this isn't needed (I don't even own a proper truing stand, just spinning my wheels while mounted somewhere), but for those building wheels daily (manufacturers, specialty shops) it can be a nice addition.
What I like about is that it doesn't replace the knowledge or process. Just enhances it. So one can do as before, but probably faster thanks to the additional info.
[0]: Discussed here at the time https://news.ycombinator.com/item?id=10410813
Just remembering this and writing it down here has me thinking I should pick that up again during high-stress times like the present.
This is a super cool project, OP. Very nice work.
You are 100% right that tension is a critical wheel dimension.
Interesting tool, although I`m not a wheel builder. Its a real craftsmanship ;)
I think the big difference between your use case and mine is simply that I don't have the luxury of rebuilding my wheels every three weeks but they have to last for years. I'm sure that if you treat them as disposables that you can get much closer to the limit, but the bike shop where I worked built ordinary bikes for ordinary people, and then long term reliability is far more important than to squeeze the last little bit of stiffness out of a wheel, though I can see that even in that case there might be some gain from being able to do that.
Keep in mind that this was - and in many places still is - a pretty low tech affair and broken spokes on a bike through normal use on a properly maintained bike in principle should not happen. Usually that indicates that either something got abused, badly mounted or left without maintenance for too long.
Higher tension is related to higher ultimate load capacity and better fatigue resistance.
Sure, but when they go slack you've lost the plot somewhere along the line. That should - in principle - never happen.
> Properly functioning wheels operate in the linear elastic region.
Yes, more simply put: they are non-deforming springs.
> Higher tension is related to higher ultimate load capacity and better fatigue resistance.
Up to a point!
If so I'm really curious what particular numbers you were chasing to determine what the 'better' wheel was. I have my own ideas on this which is why I'm interested.
Its benefits reside chiefly in the process and I argue better process leads to better wheels. Wheel quality depends on knowledge, time allowed, and concern. By capturing and presenting wheel information this way, you can get the most from your knowledge and skill. By working faster, you can do a better job in the same amount of time.
So there are some objective qualities that you could judge wheels by. Consistency is key, and knowing where the limits of the materials used are and how far away from those you are. An under-tensioned wheel is safer than an overtensioned one, the undertensioned wheel will fail gracefully, the overtensioned one will desintegrate.
If you are optimizing for speed of building that's another matter altogether, I was hoping for a clear and objective difference in quality of build.
Well...an undertensioned wheel is a recipe for broken spokes. Why not correctly tension a wheel? The correct tension is quite a lot higher than most builders go. An overtensioned wheel is not very easy to produce, at high tensions truing the wheel becomes super-critical in that tiny changes move the rim absurd amounts, and that is the point to back off.
I have heard of top level downhillers using minimal spoke tension for better compliance and traction. They also have professional mechanics and piles of wheels to use for a race weekend. Meaning their wheels have to be just reliable enough to hold together for a 4 minute race run.
But they do lose tension over time, so it doesn't hurt to periodically check. That's also a good way to spot cracks in rims, which and do happen especially on bikes that are built once and then used for years.
Paul Aston (World Cup pack fill, former Pinkbike journalist) also made note of experimenting with extremely low tension and implied it worked pretty well: https://www.downtimepodcast.com/paul-aston-2021/
Really though, where you have the resources to experiment with something like spoke tension, you are likely to end up with a couple outliers.
Overtensioning is actually pretty easy, and I've seen more than one wheel respoked by novices that were overtensioned to the point that they were simply dangerous (because when one spoke goes the wheel will immediately respond and if you're unlucky it could even break).
Not quite, but it is engineering.
> Overtensioning is actually pretty easy
Again what materials are you using? When at optimal tensions in a mtb wheel from mavic, you would already be turning really hard and in danger of damaging the nipples before overtensioning. It really is not that easy if you tensioned the wheel evenly
Engineers will use math to get to their solutions, and will then back off from that 'perfect' solution to give them a safety margin to take into account excursions into borderline overload, material defects and so on all balanced against costs.
That does not add up to me.
You can go by tone to a pretty high degree of consistency.
Still, I trust my ability to read a tension meter more than my ability to match pitch. Props to anyone who feels otherwise - pitch pipes are much cheaper than good tension meters.
e.g. https://apps.apple.com/gb/app/spoke-tension-gauge/id51887082...
There are three failure modes that I've seen for an over-tensioned wheel:
1) The wheel will buckle in a potato chip shape - This is generally something that will happen at build time, and can be recovered from. 2) The inner wall of the rim will pull away from the side wall. This was particularly bad with the old Mavic MA single eyelet rims, but I've seen it on at least one other rim as well, a lightweight MTB rim laced as a tandem rear. (Completely inappropriate choice of components) 3) Spokes can be improperly tightened without lubrication in the threads, causing windup which later (when unloaded under tire pressure and rolling loads) causes the pinging sound of the wheel going out of true. This is not a structural failure, but it does cause the wheel to require attention.
For the buckling limit case, the ultimate load depends on the torsional stiffness of the rim, and a few other minor factors. Box or closed section rims are much better, U shaped rims are bad. Paradoxically, thinner spokes are better, and you need to lubricate the nipple threads and the contact with the rim. I used to really like the Mavic Open4 rims with the double eyelets, but that's gone out of style now.
Yes, I've seen a couple of those, typically mail order or equivalent bikes sold without a mechanic involved in the sales process. Guess who gets to fix them :)
> They're a lot easier to build, because spoke windup and nipple galling don't start to be an issue until you get to decent tensions.
Lubrication during build is the key I think.
> The wheel will buckle in a potato chip shape - This is generally something that will happen at build time, and can be recovered from.
Interesting, I've never seen this at build time but I've seen people that build their own wheels crash terribly because of this, so far only (fortunately) rear wheels. Just thinking about having that happen to a front wheel while on the move is enough to give me views of dentist offices.
> The inner wall of the rim will pull away from the side wall. This was particularly bad with the old Mavic MA single eyelet rims, but I've seen it on at least one other rim as well, a lightweight MTB rim laced as a tandem rear. (Completely inappropriate choice of components)
This I've never seen.
> Spokes can be improperly tightened without lubrication in the threads, causing windup which later (when unloaded under tire pressure and rolling loads) causes the pinging sound of the wheel going out of true. This is not a structural failure, but it does cause the wheel to require attention.
This is the main thing I've come across frequency wise. I suspect some manufacturers don't particularly care about what they ship as long as the customer pays and it makes it out of warranty.
> For the buckling limit case, the ultimate load depends on the torsional stiffness of the rim, and a few other minor factors. Box or closed section rims are much better, U shaped rims are bad.
Yes, logical too. Box or closed section rims can be ridiculously stiff.
> Paradoxically, thinner spokes are better, and you need to lubricate the nipple threads and the contact with the rim.
Can you explain the 'thinner spokes are better' bit? I use thicker spokes on the gear side if a cassette is very high so the wheel is almost flat on one side to get symmetrical tension, but otherwise equal on both sides and thicker for heavier loaded bikes (such as tandems). Would love to understand this bit.
> You need to lubricate the nipple threads and the contact with the rim
Yes, this is key. You won't be able to get the spokes properly tensioned if you don't do that (or you end up eating up the hole around the spoke nipple). That's a great way to ruin a rim or to end up with busted spoke nipples.
Oh, and also important: use the proper key! (not those round ones but the ones that go over and on, obviously sized exactly for the nipples you use).
The rim deflects inward as it contacts the ground. This is controlled by the stiffness of the rim. The deflection untensions the spoke. The cycle of tension/untension as the wheel rotates causes fatigue and also if the tension reduces to near zero allows the nipples to unwind. A thinner spoke elongates more for a given tension, so the rim deflection reduces tension proportionally less.
For example, given a thin spoke that elongates 5mm under tension, and a thick spoke that elongates 2mm, a 2mm rim deflection reduces tension 40% on the thin spoke and 100% on the thick spoke. So the thick spoke will fatigue and fail faster.
Ideally use the thinnest spokes that can deliver the desired wheel tension. This is not commonly done in cheap wheels because thin spokes have more windup and more spokes interact when truing so the build takes more time and care.
The key is that spokes never fail from tensile overload (barring something like a branch going through the wheel), they fail from fatigue cracks. A spoke will be unbuildable before it has too little tensile strength.
The MA had 2cm long cracks in a similar location, maybe gapped 1mm or so, at most of the drive side spokes.
Another thing I've seen is rims with the spoke nipples pulling so hard that the rim material was flowing upwards, so you got all these little bulges (they definitely weren't designed like that, not all of the spokes had them).
Two questions: Is there any allowance/procedure for setting the lateral center? What about detecting angle or rotation for matching tension/run out adjustments to specific spokes? I guess you could track your input values and use those to indicate direction and approximate location.
I don’t see any reason why it wouldn’t be, just asking the dumb question. Plus this seems really valuable for mountain bikers, especially if you’re into downhill or enduro style riding where knocking a wheel out of true is a regular occurrence.
Marketing to motorcycle mechanics is one of my growth ideas but I'm focused on bicycle wheels for the moment because that's the niche I come from.
But now that I think about it, Turing Stand is a name with great potential. ;-)
It's easy to make (or buy) a shitty wheel, but if you commute on a bike, you need to invest in well built wheels
According to fairly widespread bike folklore (i.e., in the absence of real stats), machine built wheels tend to start out with insufficient tension. Correcting that one issue will result in a more stable and longer lasting wheel. I've seen this on two bikes in my family's fleet, both were new from bike shops, and of reputable brands. Our oldest bikes, with hand made wheels, have stayed put for decades.
I recently re-spoked my s-pedelec because I didn't like the spoke brand and nipples used, that thing is too heavy and too fast to take any chances with.
Elastic deformation is not a time dependent property, and should be the regime in which the wheel is operating.
Plastic deformation is (also not time dependent) where you have gone beyond the yield point of the material, and have permanently changed the shape, even after unloading the part. All of the plastic deformation of wheel components should happen at build time.
Creep is when a constant load causes additional time dependent strain. There shouldn't be anything in a wheel that creeps, but it's possible that some plastics or epoxy/composites could creep.
I suspect this is true, except that parts being what they are (always with small inconsistencies) and the spoke nipples riding inside the rim and j bends in the spokes riding inside the holes in the hub tend to 'find their spot' after being exercised for a while. I've made it a pretty hard rule to re-check after 6 weeks and invariably something has shifted. This probably indicates that my wheel building technique could be better, then again, I've never had a wheel that I built fail - so far - and over the years have done between 100 and 200, some of them for very heavily loaded bikes (tandem trekking bikes).
Most recent wheel was actually this weekend, I'll be sure to give it another really good look to see if I missed something that might cause this which I can catch at an earlier stage.
My typical wheels: double walled aluminum rims, quality spokes and nipples (and the latter seem to be hit-and-miss, I've had bad batches of nipples more than once in spite of re-ordering the exact same kind, but I noticed it immediately during assembly), typically Shimano hubs.
Usually I put the wheel back on the stand after a week or two of riding. A really good builder shouldn't need to do this, but part of this whole exercise is to evaluate and improve my skills as I build more wheels. And I'm not building racing wheels, but trying to do the best possible job is part of the learning process.
1) Stress relieving is tensioning the spokes by grabbing pairs and squeezing them. This takes a elastic bending moment in the j-bend and over-stresses it into plastic deformation, permanently changing the shape of the spoke. When relaxed from the stress relieving, the spoke is bent differently, and the stress in the spoke is more uniform with less of a bending moment. (bending moments lead to a compressive stress on one side and tension on the other, superimposed over the tension of the spoke. If the compressive side of the spoke winds up with an actual stress reversal on every wheel revolution, it will start to crack and fail in O(1e6) cycles, or 2000km). Due to the overstress here, this also beds the spoke into the hub.
2) Windup comes from the spoke being a long torsional spring. There's friction between the spoke threads and the nipple, and if the threads aren't lubricated, the friction is enough to twist the spoke instead of tightening the thread. You'll still see some of this with thinner spokes and higher tension, but you can back off a bit on each adjustment and make sure that the spoke isn't twisted before going on. This windup causes the pinging when a new wheel is used for the first time, and each spoke is somewhat unloaded when it's at the bottom of the rotation. This reduces the friction in the threads, and the spoke springs back, changing it's total length.
Incidentally, the highest compression in the rim and highest tension ever in the spokes is in the stress relieving step of wheel building. This is where a super tensioned wheel will potato chip buckle if it's going to. Adding a tire and air pressure reduces the spoke tension. When riding, the bottom ~4ish spokes detension somewhat (depends on the spoke count, numbers are for old school 32ish/ 700c not terribly deep rims).
I believe this is one of the important steps in making a wheel stay true and not need trueing after one ride. This is described better in the Art of Wheelbuilding if you want to try it.
The tire and air pressure thing is perfectly logical and anybody can demonstrate this, as you pump up the tire the spoke pitch goes down.
That sounds like you were ripped off. It isn't hard to do and it isn't hard to do right. It takes very little in terms of investment in tools (the most important thing is a stable stand so you can rotate the wheel, an old fork with a guide attached will do fine for this, and a $15 hardened spoke key).
i guess this is more of a comment on the sort of people who would take the time to let us know how little they need help because they are so talented, when all it does is show how little they can understand others needs
This happens in any technical discipline -- two people will disagree diametrically on the amount of gear and technique needed, yet achieve identical results. And nobody knows why.
So my own reaction is that equipment like this could benefit someone who is supporting competitive cyclists (including themselves), such a person knows who they are, and has already built a few wheels. But "the rest of us" sometimes just need a reassurance that much more modest tooling will get you to a satisfactory wheel that will last a long time. Likewise for routine periodic maintenance such as tensioning and truing. My goal is decent truth, zero spoke breakage, minimal re-truing later on.
Here is a fantastic, compact and very much to the point guide on how to spoke wheels (in dutch, google translate is your friend):
I wonder if the common thread is that these activities require a high level of skill but don't pay very well and are tiny markets, so there's no way to do the R&D needed to automate production.
One recent weird thing on a brand new bike was a set of spokes that had the inside and the outside exchanged leading to all of the spokes rubbing gaps in each other. I still wonder what the story was about that one, it makes absolutely no sense at all that an error like that would be made in a mass produced bike and no sane bike mechanic would spoke a wheel like that.
By day I'm an industrial physicist, and I've designed systems for doing automated mechanical adjustment. There's an 80/20 rule, where tightening the specs can dramatically increase the cycle time. So, you can make more widgets per hour if you relax the specs.
Since this part of the thread is kind of about that question, I would like to ask: how come? Isn't machines' consistency something that could be very useful here? And if not, couldn't tools like the one presented by the original post help the machines reach a high standard?
So, and I also clicked through with a pretty skeptical attitude.
But it didn't take many seconds to say "oh, COOL!". Perhaps it is just that I now work in a field where tolerances in the thousandths of an inch are ordinary, but I would have thought this was way cool back then too.
Now, would I spend the USD$785 for it as a hobbyist? Not likely, unless I got really serious about racing again.
But if I built wheels on any more regular or professional basis, it's the first tool I'd get after the spoke wrench set and truing stand.
Of course, the first improvement I'd really want is a way to track the locations of warps on the circumference of the rim and visualize them (e.g., an angular sensor and a way to measure a starting point such as the air valve hole). I'd also want to be sure that this whole setup does not require an internet connection. Of course, I'd be happy to share data if it could create some general benefit of big data analysis and I could share in that benefit, but it'd have to be optional.
To answer your question in the last paragraph, Wheel Analytics does not require an Internet connection. There is no phone home, no telemetry, no checking for software updates, etc. There are no cloud components that can fail or be withdrawn/changed.
Also excellent news about the ability to work stand-alone / no connection!
thanks!
Good point on the tensioning - higher tension makes the trueing really finicky. I haven't done my Mtn Bike wheels, but my current thinking on tension is that I'd probably go with fairly tense on the rear wheel to minimize power losses, but on the slacker side in the front. High tension wheels are also much closer to catastrophic failure or folding, which I really don't want anywhere near a situation where my wheels are taking a big impact. I've also been surprised a few times how well my bike was riding after discovering that my spokes were quite slack - kind of like it creates a bit of suspension action. Just thoughts on things to try next...
Another way to look at it is that the higher tension gives more force holding the rim where it should be. Catastrophic failure or folding is a result of heavy impact, not tension. Unless you jump off buildings on your bike this should be very rare. Are you really seing these kind of failures with modern mtb rims from quality manufacturers. Even at downhill I would expect most wheels to be replaced due to denting or heavy buckling, not folding?!?
> I've also been surprised a few times how well my bike was riding after discovering that my spokes were quite slack - kind of like it creates a bit of suspension action
Interesting, I hate that feeling because loose front wheels deflect sideways in corners, which is kind of what you pay money for suspension not to do! Your money, your choice.
That's true, but kerb impacts are pretty common when cycling a lot in traffic, especially the rear (though, intuitively I would assume that that detensions the spokes rather than that it tensions them). For the front not so much, you can usually pull up the front in time. But on a bike heavy with shopping you may not always have that luxury.
I think I understand where you are coming from: competition MTB is a pretty interesting niche and it allows you to really max out on the bike for those conditions. But it makes me wonder how long such a very tight setup would last in everyday use over 10K km / year or so. Because that's my application, I've never done any MTB / offroading and at a guess stuff breaks and gets replaced far more frequently in that setting.
Sort of. I'm pretty sure that the situation is basically a pre-load on a spring, and the spokes are tension springs. So, yes, you pre-load a spring and it will make the mechanism stiffer upon the initial force application. But, the spring is also that much closer to it's failure limit both in available travel and available force absorbtion capacity.
What I noticed was that I've been surprised on a good number of occasions to find little noticeable deflection even when I've checked my spokes on coming home and found them looser than I expected. They aren't sloppy loose or anything, but just loose enough that a good finger squeeze of two spokes would yield a few mm of motion, instead of twanging like a piano string. And I've been lazy enough to go out after noticing that a few times before re-tensioning them, with no ill effects. Hence my thought about really tight rear, and (slightly) loose front tuning. But yeah, something to test, not just go with ;-)
The other thing that I've noticed is that one can get a wheel so tight that it will fail catastrophically if one spoke/thread/seat fails - that gap in the tension structure can cause the pull from the other spokes to be so out of balance that it'll fold the rim. Seems to be on low-spoke-count lightweight wheels. So, I'm a bit skeptical of that approach.
I think he'd like this system, as it provides a faster way to properly build up a wheel with well balanced, proper tension. The recording options would be welcomed as documentation of the wheel build.
Thanks for your contributions about wheels elsewhere in this thread (I've restricted my comments to the tooling). You demonstrate knowledge that is uncommon even among people paid to work on wheels.
And I'm sure that's only a portion of what he posted.