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A couple of Chinese stores have been selling folding handlebars:

enter image description here

At first glance this appears to be a great idea since the handlebar width is one of the reasons that carrying and storing bikes can be a problem.

From an engineering standpoint, are these types of handlebars feasible?

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    I've seen worse ideas. The plastic hinge blocks would appear to be the weakest link -- they could disintegrate or the connection with the center part could suddenly twist. The threaded connection between the two halves of the handlebar should be about as good as a S+S frame connector for folding bikes, though. (That is, pretty good.) But of course one would need to use care when securing the nut. – Daniel R Hicks Feb 5 '16 at 20:47
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    Another potential point of failure is where the handlebar is drilled through for the pivot bolts. This would put substantial stress on the bar tube and the tube could crack and fail at that point. But the design, with the threaded connector solidly binding together the two halves, should minimize stress at this point, of the materials are properly chosen and the manufacturing process is appropriate. – Daniel R Hicks Feb 5 '16 at 20:50
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    Folding pedals do exist too... amzn.com/B0013GAR6M ;-) – renesis Feb 6 '16 at 0:08
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    @ Frisbee, Yes they do look like folding pedals, that is the only image provided on Sunlite's site goo.gl/IKb7t1 – renesis Feb 6 '16 at 0:18
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    @Frisbee, I never said they did. Why do you think I linked to a folding pedal in my first comment? I said they exist. I didn't say they were on the bike. – renesis Feb 6 '16 at 0:37
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Well, from an engineering standpoint, no. It increases complexity, cost and weight. Those might be a deal breaker for the commuters who would likely use them. From a practical standpoint, maybe. @NL_Derek; you could be the first to test one!

In conjunction with other folding components (frame like a Dahon & pedals), it may suit the users need, imagine putting your bike in a suitcase.

If we assume that the design criteria are such that we need a folding handlebar, nothing here jumps out at me as anything that could not be adequately addressed with quality engineering. You could say a folding bike or folding pedals appear to be very dangerous, but if they are well engineered and manufactured with quality, there is nothing inherently dangerous about them. Whether this particular item is well made, can't say. @RoboKaren, I'd agree that something other than the threaded connection between the two halves might be better unless it has some measure preventing it from loosening unexpectedly, like a cam-lock mechanism of some sort.

Just for kicks, I modeled up what in my estimation would be a sturdy hinge assembly, if made with the right materials, roughly copying the design of what is shown in the picture. I don’t have time to do a joining detail though…

enter image description here

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    Thanks for the tip @renesis, the price is reasonable (€20) but I don't like straight handlebars so they're not for me. – NL_Derek Feb 6 '16 at 21:50
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Running through a quick list of "engineering considerations" that I've just made up:

  1. cost
    These will cost more to design, test, manufacture and assemble at point of sale than conventional handlebars. They're more complex, so I can't see any way around the extra cost. The benefit seems to be slim outside of some fairly specialised scanarios, and for many of those a conventional folding bike is probably a better choice - in a house where bikes are left in the hallway, for example, a folding bike might be able to be stored elsewhere, freeing up even more space in the hallway.
    Since most bikes are built to a price point, especially at the commodity end which the picture suggests is the target for this model, the extra cost of the folding bars has to come from other parts of the bike.
  2. weight
    For equivalent materials and design, these will be heavier. On cheap bikes and BSO's this isn't an issue, but for a bike where an extra $20 for folding bars isn't an issue, weight usually is. Again, this just means the folding bars have to be useful enough to overcome the disadvantage, but it will serve to somewhat limit the market.
  3. failure modes
    Obviously two pivots and a join mean there are more ways for this to fail. As well, since it's a new design we don't have 200-odd years if history to look back on. So it's going to require more testing and more experimentation to work out how it fails and how to minimise the extra failure modes.
  4. aesthetics/customer perception
    This is possibly more "sales engineering", but they look odd. Most people like to fit in, and looking odd means less of that. Again, shrinking the market for the product.
  5. complexity of operation
    It's a couple more steps every time you have to fold them. It likely takes as long to fold the bars as it does to fold a decent folding bike (I used to ride a Birdy and would often half-fold it just to park it). Even if they're not being folded or unfolded, that lockring in the centre should be checked every time the bike is ridden.
  6. legal liability
    Again, not a factor everywhere, and not a factor at all if you're buying from a Chinese website. But the extra failure modes, extra operator checks required, and unusual design would make lawyers in a country like the US unhappy. Or excited, depending on which side of the case they're on.

It's the sort of thing that I would happily buy if it filled a need I had, but I would also be aware of the above and take care with the folding handlebars when I got them. For my folding-bed load bike they might have worked better than the "just turn the handlebars a bit" approach I used when I parked that in a hallway. But I didn't buy a set even though I'd seen pictures of them, because I wasn't convinced that they'd work well enough to make up for the above problems.

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Other posters have pointed out that it's vulnerable to catastrophic failure, so I wouldn't use it for my 60mph racer (if I had one !-). But for an everyday getting-from-A-to-B bike, it sounds like a great idea. I have often needed to loosen the handlebars to fit a disabled (flat tyre, lost key, etc.) bike into a car (using a handy stone if I don't have a hammer), this would simplify things quite a bit.
I'd need to see and feel one to assess how sturdy it really is (@DanielRHicks apparently thinks the black bits are plastic, @RoboKaren thinks they're cast metal, in any case they need to be fairly substantial).
Do you think they're going to be available in the Netherlands? If they are any good, I predict a good market!
EDIT: @renesis pointed me to the advert which makes it clear that the black is plastic (they say: "commonly used in aviation").

  • The problem that it's hard to fit bikes in cars because the front wheel and handlebars are large and at 90 degrees to each other has already been safely solved, in a way that adds almost no weight or complication to the bike: quick-release wheels. – David Richerby Sep 1 '17 at 12:28
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At first glance, these handlebars appear to be very dangerous. There are multiple points of failure any of which would immediately render the bike not only steerable but likely not allow the operator to brake either:

  • If the center locking nut fails to secure the two halves of the handlebar or if it works its way loose by vibration
  • Each half relies on the black metal casting which is set up a lever arm and thus quite vulnerable to stress fractures.
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    The center locking nut very much resembles an S&S connector of the sort often used to hold together touring bikes. These have been in use for probably 50 years and are highly respected. – Daniel R Hicks Feb 6 '16 at 2:28
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    Note that the two "castings" need to somehow clamp the ends of that center stub. It's not clear how that works. – Daniel R Hicks Feb 6 '16 at 2:32
  • I don't like the idea, but I have to say I disagree with you: Let's say one hinge pin falls out as a result of vibrations -- most riders can steer with one hand and there's still one brake. If the handlebar failed going over a pothole, things would be much worse, as you'd likely go over/through the bars. But assuming these are going on small-wheeled folding bikes, avoiding potholes would seem to be a very good idea. I'm unlikely to buy a folding bike as I'm big and heavy and treat my bikes rather hard, similarly I wouldn't buy these bars. – Chris H Feb 6 '16 at 10:40
  • If one hinge pin falls out, the whole handlebar will pivot free from the one remaining one. I fail to see how you could still steer in that state. – RoboKaren Feb 6 '16 at 15:54
  • If one hinge pin fails, you could still pull the handle bar towards you so that it rests in the "fork" of the black castings. Or you could just grab the hinge with one hand and hold the handle bar in place. This would still give you enough control to come to a stop. I don't see why you would lose braking control, it's not like the handle bar detaches completely. It would be dodgy on a 60mph descent on a racing bike, but for the typical usage of a folding bike I don't see that this is likely to be a problem. – Stephan Matthiesen Feb 6 '16 at 19:33
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We spend a lot of effort to develop this type of folding handlebars. Our works have passed EN14766 mountainbike test. I wish you may try this one.

The innovative Smaller bicycle folding handlebar can effectively avoid the unpleasant nuisance of bicycle parking in a confined space. Without much effort, steps four take less than 3 seconds to fold the handlebar up or to fold it out.

Reliably, its material of aluminum alloy ensures its toughness and resistance,. Over the past years' tests of endurance and impact, Smaller's folding handlebar has took certification of EN14766 (Mountain-bike test).

Stylishly, the design of minimalistic line-up and the anodizing surface of black color make its simplicity without losing the concept of aesthetics.

enter image description here

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    Reading between the lines - you have something to do with this product. Please declare your association, use the Edit link to do so. But +1 for not link-spamming, which is nice. – Criggie Dec 1 '17 at 8:22
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    Could you please edit this so it looks more like an answer to the question and less like an ad for your product? The question says nothing about style, so that paragraph is completely irrelevant, for example. The rest of it is written in a style of promotion rather than information. – David Richerby Dec 1 '17 at 13:36
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    If you're using this as an example of how it should be done, perhaps it would be worth posting a little more detail on how the mechanism works. It looks like it has the potential to be more robust and/or more convenient than the one in the question (and I'm sure it's much more expensive!) – Chris H Dec 1 '17 at 16:30
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It depends on the design. I would say yes this is not that hard for someone with Engineering skills to accomplish. What I don't quite understand is why instead of having a pivot, don't they just make it with screw mounts so the ends of the handlebar can be pulled off? A safety latch could be placed on them to lock it to prevent accidentally loosening it while riding. There could also be 2 "stubs" for the handlebar ends to rest on in a vertical or near vertical position when storing or transporting. Also for times when needing to put the bike inside a car, 1 or both of the handlebar ends can be removed to take up less room and make it easier to load and unload into/from the car.

So my answer is yes if it is well designed, well constructed, and well tested. Very good idea but not for high stress bikes. Only for light duty I would say.

  • Touring? That requires some of the most reliable equipment available. I don't think you know what you are talking about. – jqning Feb 9 '16 at 5:20
  • I doubt it. A BMX stunt bike (for example) endures more peak stress than a touring bike. – David Feb 9 '16 at 12:12
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    More stress? Sure. Which is why I said some of the. Nobody is proposing that weak or fault-susceptible bars are suited for a BMX bike. However, you are identifying a touring bike as a good candidate. BMX actually does tolerate some broken parts; aside from risk of injury which exists on any bike, the downside is minimal (you can walk home). Touring on the other hand, well walking is a much less available option. Which is why I am not talking about which bike gets stressed more, I am talking about which bike should be more reliable. – jqning Feb 9 '16 at 14:00
  • Maybe generally speaking but how many bikes of a certain class are really used for that purpose? For example, I have a mountain bike and don't live anywhere near mountains so I use it as a 90% on, 10% offroad fun playbike. – David Feb 9 '16 at 15:32

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