You urgently need to inform folding bike manufacturers about that wisdom, because they keep talking about riders and dont distinct between genders. Quick!

Don't worry, all serious bike manufacturers and cyclists know this.

Then why they don't have different size charts for men and women, if the fit is not comparable and you insist females to be excluded from average height discussions? I'm wondering. Of course it has nothing to do that their average size doesn't fit your claim that most westerners dont fit on a 16" bike. You have a more important reason, right?

The height of a cyclist is only one parameter, its not enough to make a bike frame that fits.

Serious bike manufacturers ask to their customers more information to define the frame, at least inseam, or the geometry of an existing frame that fits or do a postural study to find out the needs of their customers or have several bike sizes and provide the full geometry information of these several sizes so that their customers can make an educated choice.

I never claimed that most westerns do not fit on a 16" bike, this would be totally stupid because the wheel size doesn't define the bike geometry and 16" covers several wheel sizes.

I only said that a height of 170cm or less doesn't represent the height of the majority of westerns male adults.

(above) My own unexpert opinion, male vs female sizing:

I think this distinction is more critical on large-wheel road-race bikes; Terry(?) cycles made a name for themselves by offering a woman-proportioned bike, notably with 700c rear (to use existing gearing) and a smaller front (24"? 650c?), my guess is to have the clearance with the downtube to be able to move the front axle center aft, and/or, not have toe overlap if shortening the top tube length to cope with shorter torso for a given inseam.

With typical folding bikes, this is less of a challenge; With 20"/406, for similar wheelbase, and often a bit longer than with 700c, there's acres of toe clearance in front, whereas I had some overlap issues with my old 700c road racer with tall 74 degree head and seat tube angles. With 16", the clearance is probably even better.

Further, (I am guessing on this) I think smaller wheels allow more range of horizontal stem/handlebar forward offset from steering axis. IIRC, having a long horizontal stem on 700c adds stability in turning, sometimes to a fault, feeling less agile. With small wheels, this may be less of a problem, and perhaps beneficial. Thus, more range of adjustment may be possible.

I welcome thoughts on the above.

Terry is indeed specialized in women cycling and was using 24" ETRTO520 wheels for the smallest women frames.

Bikefriday has a sizing from in which they ask for inseam and for the geometry of an existing bike that fits the customer.

Trek has women bikes of all kind.

Giant has Liv a special brand for women...

Now its a fact that there are less female cyclists than male cyclists and that the market for women bikes is smaller than for men bikes, especially in high end bikes (its less the case for utility bikes, city bikes, cargo bikes...).

...yes totally

I wrote "For the ETRTO305 folding bikes, you are right they have usually a very short frame that doesn't fit for most US and European cyclists".

Usually, doesn't mean that all ETRTO305 bikes have all a short frame!

But many have a short frame because originally, ETRTO305 was a kid bike wheel size.

And I wrote ETRTO305, not 16" that cover two common rim diameters, ETRTO305 and ETRTO349. ETRTO349, a wheel size used originally for the Brompton, is mostly used for adult folding bikes (some trikes and velomobile also use ETRTO349 for their front wheels).

AliExpress, in my experience will not accept returns, even when the wrong item is sent. I suppose you can challenge this if you pay by credit card. I still buy from them.

I suppose bikes could be designed by computer programs by knowing your proportions, and even built by programs to automate the construction of them.

Another variable in sizing the bike is flexibility of the individual. This often accounts for why some people can ride a bicycle that seems would be under-sized for most. For most of us, we lose flexibility as we age, unless we use that flexibility, a use it or lose it.

The original assertion, before the moving of the goalposts and the backtracking started, was that 16" bi-folds of the Litepro, FnHon, etc. pedigree, do not fit most Europeans (and US Americans) due to their taller stature. I have said -- it's part of the forum record -- that they are only appropriate for people up to about 180cm. Pinigis claims the Origami Lotus fits riders up to 190cm (6'3"). A European forum member, a German who rides a 16" bi-fold FnHon Zephyr without apparent problem is 180cm in height. So, let's test the original assertion. What does the data say about these folding bikes fitting Europeans and Americans? What percentage of European and U.S. adults are of stature 180cm or below?

The data, in fact, show -- contrary to the original assertion -- that the majority, more than 50% of adult Europeans -- males and females-- are of no more than 180cm in stature, and therefore can potentially fit in 16" bi-fold. The data show that 61% and 99% of European adult males and females, respectively, and 66% and nearly 100% of U.S. adult males and females, respectively, are no taller than 180cm.




The results are illustrated in the following graphs:





Source: publicly available data on the mean height and standard deviation of European and U.S. adults.

What do these percentages mean in absolute figures? In the case of Europe, they represent a good half a billion people. Yes, billion. I didn't calculate it for the U.S, but it's gotta be -- a guesstimate -- around 200 million folks.
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Naturally, there are regional and country variations. We know that. You are welcome to carry out similar calculations for individual countries. But the original assertion was about Europe/Europeans (and the U.S), not about specific nationalities or countries, and variability among countries does not disprove the overall aggregate finding, or prove the original assertion.





For U.S. Americans befuddled by metric, an inch is 2.54cm.

(above) Bravo. Well done.

Question: Those who are too big for a typical 16" bifold, is it because
- the seat and handlebars don't go up high enough?
- the reach with standard handlepost forward tilt, is not long enough?

Height I think can be solved, if the parts are available.

Reach is tougher, as too far forward of the steering axis, handling may get funny.

In order to demonstrate that you are right, you continuously increase the maximum height for which these short frame bi-fold fits.

The initial claim was that they are OK for you and since you are 170cm, they are OK up to 170cm meaning they fit for most people.

But 170cm max is only a minority of westerners.

Then, without any explanation, you increased the max height OK for bi-fold to 175cm.

Unfortunately, this is not enough to claim that they fit for the majority of western male adults.

So, now you increase the max height to 180cm based on the claim of we don't know who, that 180cm fits on those short wheelbase bi-fold.

What I can say based on my personal experience is that its not true for at least one of those short bi-fold, the Btwin Fold Light, on which the position is too upright due to the frame shortness.

The picture below is an official picture of Btwin/Decathlon published by Btwin to promote this bike.


Some more showing the same upright position:

Well that seems to confirm my suspicion that the issue for tall is not height, but reach. This reminds me of my first-gen Dahon, my knees would sometimes hit the handlebars when standing climbing. But notice in the above bike, how close in angle the handlepost is to the steering axis; I think that has room for at least a vertical post, possibly forward-canting. The head tube may be a bit laid back in angle, hard to tell because the frame monotube intersects at a much different angle than my bike, but Bromptons also have a similar head tube angle I think, and they steer fine with more forward handleposts.

Is it me, or does that bike have a double-folding handlepost with two hinges?

Note that the image is a red-herring for it is not of the type, make or geometry of the bikes under discussion. Moving the goalposts again. I wouldn't ride that bike either!
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Read it again. The rationale for the threshold is explained in the post. You are either not able or willing to understand the thresholds chosen. 175cm was a conservative threshold, and even that one disproved your original assertion. The more realistic threshold of 180cm -- one supported by user testimony on the channel, including my own going back several months -- blew it out of the water. I am 170cm, so what? These bikes fit even taller folks. How much taller? Up to 180cm. As attested by actual users!

​​​​​​I have shown with actual data that a good half a billion adults in Europe are no taller than 180cm, and therefore could potentially fit in one of these bikes. But you apparently didn't understand the analysis or have chosen to ignore its conclusion. It's quite understandable, I get it. You say something about your own continent, you make up stuff without thinking about it more deeply, you lack basic numeracy to know the blind spots in what you say, and a foreigner corrects your ignorance about your own home with hard data. Embarrassing, I know. And this largely explains your reaction now. Continued denial in the face of unassailable evidence that your original assertion has been disproven.

Thank you very much. But to be fair, the credit belongs to de Moivre, Gauss and Laplace.

Ever hear the story about the time Napoleon questioned Laplace?

Geometry on a folder is often compromised; I find my helios compromised compared to my smooth hound and other bikes.

One thing to consider too when it comes to tall rider is the mechanical integrity; unlike classic bike, folders tend to be 1 frame set fits all so, when a tall rider (180cm, likely ~85cm leg length) extends the seatpost, the loads are greater the a 165cm rider ( ~75cm leg length).

I always wonder how do they define their worst case when sayin 105kg max? is it 105kg and 180cm mannequin?

Note: I know this is a "original subject topic" wonder...

Yes, the issue is that due to the short frame (chosen to obtain a short folded length), the reach and distance between the saddle and handlebar are short with as consequence a very upright position and the knees coming close to the handlebar.

An upright position on the bike is uncomfortable for the back, all the shocks are transmitted to the spine.

For short rides and a short ride time on the bike, its usable, but not for longer rides that take a longer time.

An upright position provides confidence for inexperienced cyclists, there are often relatively short inexperienced people who choose an H stem Brompton because they feel more confident on it and after a while complain about back/spine pain.

Worst case is (factory OEM) seatpost at maximum extension, with maximum rider weight. The seatpost extension matters more than the rider height per se, but is due to rider height. Due to rider weight, that will exert worst-case aft moment loads on seatpost and seat tube, stress is an issue. Lateral loads there are not as big an issue. Pedaling loads will input to the frame slightly different based on seatpost extension and assuming a seated rider, but not as much a factor, because: The other frame tubes, handlepost, etc, are designed more based on minimum stiffness required, so stresses tend to not be max allowed for material.

In cyclic fatigue testing, there will be a lab test devised based on max weight and max peak G-loading, and may be a constant load cyclic test, or a histogram of loads. Sometimes this is calculated, sometimes the manufacturer has data from instrumenting a bike with accelerometers and riding it over roughest anticipated terrain. Lab tests are faster than road course testing, but are only valid if well-correlated with real-world tests. That data and correlation are closely guarded proprietary information. Which is why, when you see on aftermarket part packaging, "Meets or exceeds OEM specifications!", it's usually a lie, because that aftermarket maker does not have access to the OEM specs unless they are provided, such as if the OEM wants the aftermarket maker to produce service parts because the OEM doesn't, and they don't want their customers left high-and-dry because no repair parts available. Usually the aftermarket parts maker obtains the OEM part, and pulls it apart and copies as closely as possible, the dimensions, and material specs through material testing. The most difficult thing to copy are the manufacturing processes, which are not visible on the finished part.

But Jipe remember that you posted that the beaches in Korea were crowded. Don't forget that. Also, Decathlon or Btwin says the bike can accommodate riders up to 195 cm. and they say they tested this on real human riders. And also keep in mind that the goal post keep shifting to suit the ego of he who must never be shown to be wrong. Besides, 750 English for this bike and no disks.

Yes, like almost everywhere, the beaches in Korea are crowded, this is also demonstrated by the tourism infrastructure present on several of these beaches.

Now, if someone goes outside the holiday time, also like almost at every holiday place, there are few people.

The max height given by Btwin is defined by the length of the seatpost that is long enough for up to 195cm.

But the position of cyclist 195cm tall will be completely uncomfortable with its knees almost touching the handlebar (look at the pictures of the two male riders on the Btwin, these were published by Btwin).

I showed this bike because the famous 16" Fnhon Gust (that Ron seem to uses seldom, most pictures of long distances ride he published show the FSIR Spin 5 with ETRTO406 wheels) is not available in Europe. The two other bikes bi-fold (Fnhon Storm and Literpro Spyder) showed by Ron were never used because still not completely mounted.

Seems that Btwin took a 305 wheel folder added long seatpost and handlebar as to sell it to Europeans. As it appears, I could probably ride it. Would I want to, though? It is designed for Europeans, except for the frame, but what does that matter? It may have been designed from the ground up for Europeans but if so, not well. Seems like the geometry angles could have been tweaked to extend the reach. It is interesting that they went with single bladed forks. Likely to save on fold space That may account for why it is priced as high as it is. I also don't like that they put a light where the luggage block should be.

Btwin has other, cheaper, bi-fold folding bikes.

You are right, the unique selling proposition of this bike is its smaller folded size, also small folded width obtained by the single side fork. This smaller folded size should make customers accept to pay a higher price.

The short frame and short wheelbase is a consequence of this goal to have a small fold: it reduces the folded length. Note that Btwin doesn't specify the wheelbase (thought, you can deduct it from the overall length and overall wheel diameter)

To make it usable for taller riders, Btwin put a very long seatpost and very high stem.

The bike has also a front block to carry a specific front bag similar to the one of Brompton.

The target customer for this bike is multimodal commuters riding short distances doing the biggest part of their commuting by train, bus, car... Therefore the importance of the small folded size, ease to fold and ease to carry folded advertised by Btwin.

Decathlon, the owner of the Btwin brand, has a lot of shops. I know several people who bought this bike and didn't liked at all. This is the reason why I could test it myself.

I thought that was a headlight not a luggage block. Weight wise they match or exceed Bromptons. I would try it for the experience, if I could.

Its easy to save weight because several easy replaceable components are heavy (pedals, saddle, seatpost, the kind of foot on which the folded bike stay...).

Many new commuting cyclists bought that bike because they didn't want to pay the price of a Brompton and eventually swapped for a Brompton!