Yes, Bromptons are expensive. But they ride like a bicycle, have gears, a stiff enough frame, luggage racks etc. There's very little compromise. The fastest I've done on mine is 45 kph and I've ridden 70km in a day. I carry it on and off buses and trains multiple times a day without issue.
In the past I had an A-bike[2]. It's a fun and cute little design but the wheels are absolutely tiny and has no gears. You feel like you're riding a folding contraption rather than a bicycle. The build quality was rather plasticky too. I like the idea of an A-shape with telescoping tubes. It's quite an ingenious fold.
I've also ridden (but not owned) a Pacific CarryMe[3]. The ride experience again suffers for the short wheels and no gears, but it could be useful for some. The fold still leaves you with quite a long package.
I'd love to try the Kwiggle bike. I don't think the strange seat will cause as many problems as people think, but I suspect the overall ride experience to be a bit bouncy and flexy. Maybe it's worth it for the small fold.
For a more out-there design I think the Halbrad/Half-Bike[4] could be quite nice but it never really got past the prototype stage. Under-seat steering is a bit of an adjustment too.
[2] https://en.wikipedia.org/wiki/A-bike
Also the fold is the most compact possible, even more compact than Brompton in terms of maximizing the use of space. It also fits in a standard airline luggage without any disassembly which few other folding bikes can claim.
The frame is full titanium including the locking mechanisms. It’s made in Canada and is the lowest cost complete titanium bike on the market, folding or not.
Full disclosure, I’m the owner/founder of Helix. Happy to answer any questions related to it or folding bikes in general.
If you have not already done so: you should transparently write up the lessons that you have learned and how you are going to address this for your electric launch to build up confidence. I remember your kickstarter and in retrospect continue to agree with my decision to not participate (I'm the happy owner of a Brompton that I can check in airline luggage instead).
A bit of unsolicited feedback; listing the seat post options based on rider height (regular for shorter than 6’3”, and extra long for taller than 6’3”) is wrong.
Seat post height is based on how long your legs are, not how tall you are. If anything, you should list that by inseam.
As it is, I would have no idea which option is the most appropriate.
Do you have sources to back that up?
In the UK, the price on your website lists it as £2,025 (or £3,003 for the higher-end model). I can get a PlanetX titanium gravel bike for £1,799 - granted it's not folding, but you specified "folding or not"!
In my experience (and maybe you'll correlate), all materials involve compromise; there doesn't tend to be a case where a material is outstandingly better in all categories.
Comparing titanium vs. the best steels, it's half the weight but also half the modulus of elasticity and half the tensile yield strength. I wouldn't expect there to be much weight advantage when comparing two tubes with roughly equal properties but maybe this is a case of "every little bit helps"?
If I remember rightly, titanium is harder to process also.
Along the lines of my other comment, have you had any problems with Brompton around your pivoting rear wheel? Your design looks very different from the Brompton but I believe it’s that pivoting rear wheel they are quite aggressive about legally (where they can be).
That single sided front fork is genius!
I really hope you have incredible success, next time I’m looking for a folding bike I will certainly check yours out.
Additionally, I saw there are some electric options coming up in Q3, would you spare a moment to share your thoughts about possible future developments (i.e. if you see belt/ebike options expand in the future)?
Major kudos for using off-the-shelf standard components. I can't over-stress this enough.
I'm not saying I'm pulling the trigger and ordering straight away (I've had this idea in my head for well over a year, so far just waiting for a good excuse / trip idea), but it's definitely made it close to the top of my list now. Even though it's pricy at around 3k Eur, given the titanium frame it's probably still well cheaper than equivalent Brompton (Chapter 3 or such).
Can you clarify what you mean by “the fold is the most compact possible, even more compact than Brompton in terms of maximizing the use of space“
The Brompton's folded size is 585mm high x 565mm long x 270mm wide
The Helix is 580mm x 635mm x 230mm.
Helix 71.12 x 63.5 x 26.67 cm
Kwiggle 55 × 40 × 25 cm
While twice as expensive the Helix looks much more like a decent bike at roughly the same weight. Like many folding bikes and scooters the Kwiggle looks like you could get seriously injured if you hit something (small). Before your face hits the pavement you would try stick your leg forwards but it has these scary looking spikes there.
You can see the Brompton influence, one pivoting wheel and folding cross bar with a 45deg hinge. But they have had to compromise in order to not infringe the design resulting in a very odd seat design.
I have spent many many hours trying to design a fold as good as Bromptons and haven’t managed too, it’s just too perfect.
Our shop has noted that Brompton bottom brackets are low quality. Often poorly aligned to the frame and the threading frequently needs chased.
The fold on a Brompton is just about perfect. It takes no time at all. I'm a little annoyed to find that they're using copyright to keep a monopoly on it, but certainly not so much that I'm going to give it up.
I tried out a Tern, a Dahon, and some random ancient thing. I've never regretted spending the extra coin on the Brompton. The fact that all the greasy bits are in the middle when it's folded means you throw it in your trunk without thinking about it. It means you put it between your legs on the subway without thinking about it. The fact that it folds in seconds means you don't miss your train fumbling with it at the fare gate.
The only downside I can see is like half the parts on the thing are bespoke. Replacing a derailleur, for instance is not something your average shop can do. Ditto the shifters.
It's the Apple of bikes: the tight integration of the components gets you an absolutely magnificent package (at a premium price), but you get some lock-in as a result.
For example, lugging it around on public transport, or bringing it on a plane, or just dragging it around a city for the day - this thing easily wins, there’s just no comparison. I haven’t rode one of these so of course I can’t say, but the fact that they rode it all around the entire IJsselmeer (one of the largest lakes in the world) - which is a serious bike ride even on a normal bike - is a pretty good sign that this bike isn’t terrible to ride on, even if it may not quite be a Brompton. So the comparison becomes “decent portability and excellent biking” vs “excellent portability and decent biking”. I think that’s a fair tradeoff. If anything, I wish it would go further - give me half the size and a mediocre biking experience and I’d buy one in a heartbeat.
I'm very happy with mine, and it has most of the advantages you list - luggage rack, real bike feel (my longest day is apparently 64km and top speed 64kph). The sensitive steering takes a bit of getting used to the first time but you adapt quite quickly. For me the simple fold (and, sure, lower price) feels like a big advantage compared to the Brompton, which is what several of my friends have.
Regarding the cost, I'm quite sure I could sell mine for more than 800 EUR while any other alternative would lose at least 50% of the value and probably require more maintenance.
Had one for a bit, very small wheels, was kindof fun but in London its just easier to have a normal bike and arrange your commute so that you use it, rather than carry a small bike around.
I also had a Strida, really nice design and a good balance between usefulness and foldyness
I have a Decathlon foldable. It doesn't fold quite as small as a Brompton, so I wouldn't want to be regularly taking it on public transport. But it's light and solid, folds easily and rides well at about one third the price.
[1]: https://fr.brompton.com/shop/bikes/a-line?color=white&handle...
That said the bike in TFA looks interesting for multi-modal commuter use in e.g. Singapore or other such cities where a Brompton likely would not be accepted on the subway.
There's also the JZ88 (https://jz88.com/shop.html) which is claimed to be Singapore MRT-acceptable but I haven't used it.
This is an interesting idea, but I wonder if it collides into the electric scooter market.
I think dahon bikes are fairly nice, but I have not tried a brompton.
I have a dahon mu n360 with a variable transmission that I like quite a bit.
https://dahon.com/bikes/mu-n360/
However recently I bought two bikes direct e-bikes - pretty versatile and go off-road/to parks:
https://www.bikesdirect.com/products/motobecane/e-bikes-elec...
I wonder how people use their folding bikes?
I am not totally satisfied, but it is OK. I'll probably change the crank gear to be larger, the very lowest gears aren't useful right now because they are so slow.
I also can't ride it without having at least one hand on the handlebars.
Having fenders is nice, but they are very flimsy.
Price was a lot lower than a Brompton.
It’s a great tool.
Although to be fair I never worked for a company where there was at least one Brompton.
Having said that there’s something very British about it IMO. But I am not British.
It would be convenient for me to have one due to lack of space in my apartment, but from an external observer perspective they all look like too small and like I would need to ride hunched and uncomfortable, so I haven't really looked into them. But maybe it's just prejudice.
I recently ordered a frame on AliExpress [0] equipped with internal cable routing and disc brake mounts, 2.25'' tire clearance. My build looks like a gravel bike. A gravel bike on 20'' with an 11 speed cassette, a drop bar and SRAM derailleur. Of course, not to miss a great carbon sear post. Including pedals and tires, the bike accounts for 10kg. In order to take it on flights, I did sew myself a backpack to fit the bike. Taking the bike apart takes me 10 minutes. It is a tiny bit too large for hand luggage but ideal for being checked in.
For me the frame is a great compromise between size, stiffness and maintainability.
Velo orange [1] does offer a lovely frameset, too. It's just hard to get by in Europe (at a reasonable price point).
[0] https://m.alibaba.com/product/1600169443757/SILVEROCK-Chrome...
So much for German engineering in this case ;-)
Half the price of a Kwiggle [1]. Seems like a bargain to me.
[1] Comparing apples to apples, the base Brompton is a 3-speed for 850 euros. The 3-speed Kwiggle is 1690.
I then moved and I lived at one end of the Central line in Essex, about a 1 minute walk, and worked a similar distance in West London.
Took about 55 minutes for the train to go, always got a seat in both directions.
However during summer I would ride on my Bromptom one way in the morning two or three times a week - took about 24 miles, or 2 hours, I'd then fold it up and take it home on the train.
My next move was too far to ride (45 miles each way), and less than a mile from the station at each end so didn't do much commuting riding then, and I moved to be a home worker in 2011, but I still ride my Bromptom around the country lanes. Occasionally think I should upgrade to something with more than 3 gears (it's relatively hilly where I live).
The bike itself I think cost £520 back in 2005, a new one of the same model is over £1k now, not sure what the second hand value is
One of my routes includes Hampstead and Highgate, a decent amount of climb. I tried the 3 speed hire Bromptons, but went for the 6 speed when I purchased one. The upgrade was well worth the money, I doubt I'd be able to get up those hills on the 3 speed.
Good on you for doing 70km! That's about the limit of my comfortable endurance on it too. My record is~100km plus two ferry rides touring on the west coast but I admittedly walked it up the last two hills in the dark and I started to wish I was done around 85km.
What do you use for checked airline travel? I have the B&W hard case but haven't tried anything else. I think it is a linear inch or two over regulation if measured but nobody has ever stopped me or charged overage.
I'm in the process of building aluminum cases for two Zizzo folders my gf and I just bought. I'm keeping them under the size limit to be safe, but because they also convert into trailers (to haul carry-on) and are relatively beefy, I'm bumping up against the 50 lb weight limit for economy seats. Right now I'm scratching my head as to how to incorporate casters and center stands with only 1 lb left to play with. :|
I have a Zizzo and bought one for each of my immediate family members. Everyone loves it.
Amazon has reasonable pricing+availability for USA people.
I bought 3 Zizzo Forte, and 1 Zizzo Urbano. The Urbano for my 9 yo daughter to make it slightly easier for her to manage.
Kwiggle is a new movement for a flexy human being. Humans have been accustomed to putting their natural flexibility into a rigid posture on a bicycle for 200 years.
If you are thinking the bicycle from the anatomically view, you should invent a bicycle, that could be ridden upright with your flexible natural movement similar to the walking.
This was the first idea of the Kwiggle. And this is an opportunity to get back to your natural flexibility. After a little get used to, Kwiggle will adapt to your movement and not the other way round.
I really love my light aluminum non-folding bike that is pedal-powered... but if I would buy a folding bike, it would be electric-motor powered.
On the other hand, if you ride 70 Km a day - why would you even need a _folding_ bike? That means you do serious cross-country riding. Use a regular bike.
I've had an A-bike in the past as well, and while I like the idea in principle, it's essentially a scam, due to the extremely low-quality materials - some components in the transmission are made of plastic, and they're bound to break rather quickly (I think it took me just a few months, even with around 20 km/week).
The Brompton is a much better folded bike (it's a lot smaller, it actually stays folded, it doesn't have exposed greasy parts when folded, you can use it as a shopping cart, etc).
High end Terns (Verge) are more like a normal bike with good components but they are nowhere near as compact when folded (likelihood of walking it into a shop and not getting yelled at is nil, unlike with the Brompton), they don't have as good commuter accessories as the Bromptons and they ride much stiffer (which is good or bad depending on what you are doing with the bike).
Source: own both
We have been developing Kwiggle for 10 years and producing Kwiggle for almost 3 years.
Every detail has been carefully designed to create a 10kg lightweight folding bike that can even be folded into hand luggage and still go as fast as a normal bike. We have selected materials and manufacturing processes for the drive unit and rims with the highest wear resistance in the bicycle market. We use high-strength aluminum and stainless steel parts for the frame and have extensively tested the stability of the frame and drive unit dynamically and statically.
Our 35 suppliers for material, components and parts manufacture according to our requirements with highest precision, because precision is another important factor for stable and durable components of a folding bike.
In the meantime, our greatest motivation is the many enthusiastic feedbacks from our many customers, who at the moment still come mainly from Germany. We are already shipping the Kwiggle all over the world and Kwiggle already is ridden on every continent.
So we are happy if you take a close look. Please assume that we have already thought about almost every little critical detail that is discussed.
So if you are looking for a very compact folding bike, feel free to take a close look.
The movement on the Kwiggle is new, but very close to your natural walk. And when even a 85-year-old man writes to us, "I can only do two things: ride a rollator and ride a Kwiggle, but I enjoy the Kwiggle more." Then you can assume that you can ride the Kwiggle very well, too.
I know you've collected some positive anecdotes but I don't see many reviews from third parties out there yet, so I really can't commit to it. Is this simply because the product is still new? Can you say how many are already out there on the roads?
There is a first test report from a journalist of SPIEGEL:
https://www.spiegel.de/auto/faltrad-kwiggle-im-test-achtung-...
Kwiggle was part of a test of folding bikes from BikeBild:
https://www.kwigglebike.com/web/image/37936?unique=b95a1aead...
There will be further longer test reports from various journalists/media this spring.
A few months ago I bought a used folding bike for €100, equipped it with a motor and battery that cost less than €400, for use on train trips.
Nothing feels better than getting out of a long-distance train trip, unfolding your bike and going about your way in a different city... No taxis, no complex public transport map to understand, nothing but freedom.
A clever way of answering the actual first question "why so expensive?"
I guess the appeal of the folding bike is more for irregular or infrequent trips.
Totally agree on the freedom aspect. Bicycles are ideal for inner city travel. Cars should be banned. I often use public bicycle shares when I travel now which is great because you don't even have to fold/carry or lock the bike up anywhere.
Yep, this is how I use it. I have another ebike for everyday use.
Not sure about the two-bikes concept though, because long-term bike parking is still a huge problem, security-wise, esp. for ebikes.
The 200€ one won't help you if you need to fly it. Even for road trips, for 2 adults in a city car, the size constraints could be enough to not bring two biggish 200€ along.
Basically, the choice comes to a 200€ bike you never bring along, or 800/1600€ bikes you can bring anywhere.
There are two Chinese brands for the engines: Bafang and Tongsheng. Bafang has a better reputation; I used a Bafang for my first conversion (a regular MTB). But Tongshengs, in addition to being a little more affordable, are true pedal assist: power is proportional to the force you put on the pedals. It's a different experience from Bafang, but pedal assist feels better on a small folding bike, IMHO.
You can buy them on Aliexpress; look for vendors who have inventory in your country, which allows for faster shipping.
Here's the final build:
https://i.imgur.com/TBHHOc1.jpeg
... and on the road in Marseilles:
http://www.velogical-engineering.com/velospeeder/produktinfo...
As bambax said - that's not what affordable means. Affordable is all about whether the target market can afford it, not whether it's good value for the materials and work put in.
The Tikit (which is closest to the Kwiggle which is linked here) is similarly quick to fold and unfold, and quite portable. Before the scooter craze people were leery of riding a bike with smaller wheels but for most things it is fine.
My general impression has been that if you are worried about how you are going to store your bike when you get where you are going, folding bikes can be a big win.
I wouldn't take it on a crowded (UK) commuter train: the fold is much larger and more ungainly than a Brompton. But you can go touring up hill and down dale on it, on the sort of route that would leave you panting on a Brommie. Plus it works great as an everyday bike even in circumstances when folding isn't important.
I gave them a serious look and realized they weren't for me because I am not a cyclist. For me, a bike is a tool which isn't to say Bike Friday bikes aren't tools, but rather that looking at Bike Friday made it clear that a Brompton would be a better tool for me...e.g. it has a bell out of the box and doesn't anticipate I own a specialized wardrobe.
There’s no good way to store a regular bicycle. All of them are compromises of convenience, security, floor space and weather protection.
It seems like the fanny pack of bikes: pretty useful but you gotta look dorky if you want to use it.
It's vain but I'd find it hard to believe I'm alone here.
The folding bicycle is bastardized version that shoehorns the concept of portability at the expense of nearly every other quality except "gets from point A to point B".
I'm likely wrong and they probably are a great solution for many but goodness.. I love normal bicycles too much to look at a folding bike with anything but cringe.
Personally, I have a folding bike with small-ish wheels; yeah, it looks quirky, but it works well and fits in my closet, trunk, etc. so I don't care. I'd maybe buy the kwiggle too if I could afford it
I care about how I look and present myself. That's not exactly unique, and it doesn't have to be strongly tied to me caring if people think I'm "uncool".
But it’s a little more work to ride than a bicycle
Citation needed
But if I would live in a big city, I might get over that feeling, since it does seem practical.
The motivation must have been that it allows the integrated rims and hubs, which are probably much easier to manufacture than spoked wheels at this size. The downsides seem significant though: A derailleur with gears this small is going to wear very quickly, and when it is time to replace it, you just have to hope that Kwiggle is still around to supply you with spares.
I have been a bike-fiddler since my teenage years, but it was only recently (40+) I tried taking apart an intra-hub gear. To my surprise, the whole gear mechanism is fitted to the axle an can be replaced in one go [0]. The only functional parts of the hub/housing is half-bearings and ratchets. The cool approach for Kwiggle would be to replicate these and just pop in a Shimano gear.
[0]: https://si.shimano.com/pdfs/sm/SM-IHG-INTER7_ENG.pdf page 43 ff.
That and the small wheels don't inspire confidence dealing with the typical curbs & potholes that one is likely to encounter in an urban environment.
What's the use-case for folding bikes like this? Is there a pervasive lack of bike racks in certain places that would necessitate stowing a bike in such small quarters?
There are none of those nice bike racks on the front of American buses here. The whole system is fairly hostile towards active travel.
And even more hostile to PLEVs. Electric scooters still illegal (beyond a few set-up-up-to-fail rental trials), a 250W limit on eBikes, and no hope whatsoever of electric skateboards, OneWheels, and so on ever being legal on roads or pavements.
Yet still people wage war on the car, without any attempt to make alternatives more viable.
And despite the roads being at breaking point, the trains being overcrowded and ludicrously priced, and road safety/bike theft/weather deterring all but the most dedicated cyclists, somehow transport isn't even a significant political issue in the UK.
(London-centric politics doesn't help. Many Londoners, particularly politicians, don't seem to have a clue about life beyond the M25)
What I've read from people who fall into this use case is the biggest requirement is a large wheel size. (This one wouldn't be great for that reason.) You'll want big wheels and fat tires to deal with, shall we say, less than optimal road conditions. The other main requirement is, of course, some kind of load carrier. Usually some sort of trailer, though several Dahons have a carrier. Dahons are the usual go-to brand.
This bike looks like it would be a decent fit, but I'm not sure I can convince myself to shell out 1500 bucks for it... So the search for a last mile solution continues :-)
Btw. In UK on certain routes or during rush hours you can only take a foldable bike onboard.
https://www.decathlon.fr/p/velo-pliant-oxylane-120/_/R-p-120...
they actually went up in price since then. swapped stock tires because they were rubbish and also bought better seatpost from upper model. removed all the unneccessary stuff like ringer or mudguards and this thing flies. im getting average speed about 18km/h on my rides and done about 4000km so far without any problems. this is perfect city bike in my opinion. if this thing had disc brakes it would be even better.
Also, the non-inflated rubber wheels I had on the thing were very uncomfortable (and loud) on cobblestone-type roads. Almost infeasible to use, really. But otherwise it was a pretty convenient thing to have.
Wheels are small, board is short, and center of gravity is high. It just takes a small pothole covered with leaves (so, not even winter), and the driver will fly forward (I did).
E-scooters are heavier, with larger wheels and longer boards, so they may be less accident-prone, but I've never tried one.
However, the limit on how good a bike is are defined by materials and geometry together. With strong, tight and shock-absorbing enough materials, you could theoretically create a race-quality bike in a form-factor like this.
When or if such things will appear is hard to say. The Bike Friday seems to be at the quality of a decent road bike but foldable into a suitcase (they've had the same basic design for twenty years so twenty years of materials improvement might create a pretty extraordinary thing).
See: https://bikefriday.com/ (relative to other comments, slightly larger than Brompton but I think more of a bike that really can be your only bike).
I've been riding Montague Bikes for years -- on the other end of the folding bike spectrum. Full-size wheels, rides so much smoother. Doesn't fold down as small but it goes in the trunk of a car or can be carried on the train and that's all I really need.
Sometimes the the problem can't be fixed with a technical solution and the user simply needs to learn to use a new tool ;)
1. Size / Portable, about 7" x 17" x 24"
2. Agility, better maneuverability around cars and obstacles
3. Speed, can go >40mph, most of the time you only need 15~25mph
4. Hands free, can carry stuff
5. Wheel size is 16" and up (better than scooters with small wheels)
Downsides:
1. Weight, 40lbs and up (my current one is 65lbs)
2. Electric only
3. Safety - if it cuts out, your falling off (has yet to happen to me)
4. No exercise like a bike (I became much weaker after I stopped riding my bike)
5. Expensive (starts ~$1300 for basic, likely will want to spend $1800-$2400)
A big advantage EUCs have is you don't have to bother with folding like a bike, just hop off, grab the trolley handle and walk on.
Electric scooters have similar advantages but they have to compromise range, performance, and compactness for their ease of learning.
The other thing is that you actually get some light exercise on a bike. Most people with desk jobs would do well to move their bodies a bit more during their days.
One thing that's nice some times about scooters is being able to stand up tall, rather than get into a slightly hunched up position on a bike. The Kwiggle from the GP allows for quite a unique upright body position. So that may be intriguing.
300km on one day with a Kwiggle.
Brompton can sorta solve this by having front and rear cargo carry (bias: I own an older Brompton and have travelled from seattle to california by train with it. see also knockoff versions of it like https://jcat.bike/ )
Besides that you can attach a standard bike pack (e.g. from Ortlieb) to the frame of the Kwiggle or carry a backpack, of course.
It's a folding bike which lives in my car's trunk. It's also easily and quickly adjustable so that I can bring one of my other bikes for me and then set the Tern up for pretty much anyone else.
It's a little small for me and with a short wheel base, there's a limit to how steep it will go without the front wheel just lifting off the ground.
One of the positives that I've found with this bike is that I like smaller wheels, 24" rather than 700C. You accelerate faster. It might not work for a road bike doing a loop ride but for urban riding, I do like it.
When unfolded, you can’t tell at all that they’re folding bikes.
Every metro area I’ve lived in allows bikes on trains and city busses have racks on the front. Leaving a bike in a secure lobby/hallway, garage has almost always been an option. That said, I don’t hesitate to chain mine up on the street either, so I’m having trouble seeing a folding bike as offering any advantage in most situations, especially considering the compromises that are often made in comfort and performance.
For this particular one, what a unique way to mount the seat.
The stability of the ride is achieved when you relax the handlebars and the Kwiggle adapts to your movement, not vice versa. That is the whole secret.
Smaller bikes may feel less stable, however I suspect this is simply because smaller wheels will be affected by smaller road imperfections that a larger wheel would simply roll over.
[1] https://theconversation.com/how-does-a-bike-stay-upright-sur...
https://www.kwigglebike.com/en_US/faltrad-vs-rennrad-am-berg
This ride felt absolutey safe.
The trade-off is that it's quite big when it's folded and fairly awkward to carry. Unlike some folding bikes, it doesn't wheel when it's folded up so you have to lug around a fairly awkward metal lump when you're not riding it. And it rarely fits under seats on public transport - it can be quite awkward in places.
I've also found it fairly tricky to lock. The narrow gaps between the spokes and the very small triangle in the frame make it hard to pass a serious lock through; I constantly worry about wrecking spokes when I try to lock it up. It lives indoors most of the time so it's not a serious drawback for me but might be something to think about based on your needs.
Overall I've been happy with the good riding, luggage options, and replacement parts story. A good option if the drawbacks don't really hold you back in your day-to-day usage.
Montague
Changebike
There is also a third that looks newer and I could not find any info on but looks promising from Finland:
Fubi
https://www.amazon.com/Segway-Ninebot-White-GoKart-Bundle/dp...
They’ve experimented from time to time with hubless wheels, which allow for a lot of flexibility in passing bits of the bike through the plane of the wheel when folded, but it’s never clear how they deal with shock - potholes in particular.
Spoked wheels have partial failure modes and those are important.
I wonder too if at these small dimensions you still want to copy the Brompton model, where a flick of the elbow practically assembles or disassembles the bike. Would a design that requires both wheels to be removed and reattached be more workable? Though removing rear wheels can be complicated greatly by the drivetrain.
This makes me want to design one. Roughly, bigger front wheel, hard (no pneumatic) tyres. Suspension on the rear wheel; a low unsprung weight would make this effective.
It reduces the use case to short distances, not commute rides. But that's ok if it's small enough folded to be taken on a train/bus/taxi.
Have you used rollerblades or snowshoes? Showshoes have a very flexible binding system, and rollerblades need to be quite stiff in order to have a hope of functioning properly, and not snaping your ankle in several pieces. In order to make such a thing, you'd have to wear some sort of plastic boot, and then have some solid binding like a pin tech binding to attach the boot to the rollers.
25 km/hour is fairly fast for a regular ’upright’ bicycle, and certainly not obtained effortlessly. I don’t see that being better for this bicycle with its small wheels.
https://www.kwigglebike.com/en_US/home-kwiggle-vorteile
I've never ridden one so I'm not in any position to judge it, but the position sounds similar to an elliptical bike.
I don't know why you'd want to actually carry it around, but surely nobody is 'comfortable' wandering around with 10kg in one hand?!
