Lean, Mean, Green Machine

This racing bike is sure to turn heads whether you’re tearing up the asphalt or carrying it in-hand. This concept by Allen Chester G. Zhang was designed to be easily transported between work and play. It can be stowed quickly as it folds at the center to create a barely-there yet aesthetically pleasing accessory. Unfold to expose it’s natural suspension shape and gear-to-gear spokeless wheels. Fluorescent copper-zinc components add not only to it’s aesthetic appeal but the rider’s safety. The color choices on this model are a beautiful combination.

Designer: Allen Chester G. Zhang


  • James says:

    The bike looks awesome. I love the spokeless design, but as said before the gear would be way too low to be efficient. And also the center of gravity for the rider is too far back so it would be awkward riding it. If possible place the wheels farther apart, especially try and move the back wheel farther back, that would help a lot. and i would also recommend making the contact points and the rail on the front tire larger so that it would be more stable and smooth. and also, maybe not market it as a racing bike, but just as a touring bike or city bike, cuz thats what it really is. As i biker, i look forward to seeing what else you come out with in the future. thanks for showing, good work

  • Sean says:

    Not plausible for the every day rider. Looks like something out of tron, and id honestly ask who couldnt design this.


    HONESTY is what im about

  • Bob the Builder says:

    What do they teach you design students? That you can reinvent something just by making some swishy lines, taking away all practical features of something and therefore making it physically impossible? Oh I forgot if you don't mention how your reinventions are "green" then its worthless. When you throw around words like "thermoplastics" and suggest materials like titanium you are just embarrassing yourself and your profession. Do you know the physical properties of these materials or their manufacturing limits? In the future don't try and explain how you think your fantasy contraptions are actually possible, call them what they are which is just a way to show off your decent computer rendering skills.

  • Bob the Builder says:

    What do they teach you design students? That you can reinvent something just by making some swishy lines, taking away all practical features of something and therefore making it physically impossible? Oh I forgot if you don't mention how your reinventions are “green” then its worthless. When you throw around words like “thermoplastics” and suggest materials like titanium you are just embarrassing yourself and your profession. Do you know the physical properties of these materials or their manufacturing limits? In the future don't try and explain how you think your fantasy contraptions are actually possible, call them what they are which is just a way to show off your decent computer rendering skills.

  • jjjjjjjjjjj says:

    This bike has a lot of problems.

  • jjjjjjjjjjj says:

    This bike has a lot of problems.

  • Ichirou says:

    I think this is the stupidest reply iv ever seen… dont you think that this is just a concept for you to say that this is the stupidest thing you ever seen? O_o??? and by the way, all design’s are not perfect, going to the “folding” its purpose is to lessen hassle or save space specially when going outdoors duh?? common sense O_o??

  • Any designer worth their weight in salt knows to never say never

  • roger says:

    I totally agree. And what happens when you stop pedaling and the rear wheel keeps turning the gear?

  • Christian says:

    Have you ever tried real street bikes and compared them to other bikes? Because honestly your bike geomerty does not seem to fit for a racing bike.

    You do understand that you can not take isulated parts of bike geometry and join them with complete different bike geometries on other parts and espect them to function just like before?

    While I love the look, your bike seem to be one of the most inefficients designs I have ever seen. Look over function seems not a reasoable way to design … but go head build a prototype. And buy yourself a few bikes to compare, I am suggesting you try some current racer, some old classic from the 80s and a current titan frame one to notice the differences. Oh, and make sure to to use a geometry compatible to your body size and shape. Makes all the difference on longer tours.

  • Plotshred says:

    Really?! How many languages do you speak fluently? None, because you wouldn’t have said something like this if you did. Your comment is petty and arrogant.

  • Plotshred says:

    I agree with the placement of the seat and pedals.

    Try putting the seat at the point of the fold.

  • Plotshred says:

    My apologies to BaoTu. I was not paying close enough attention to whom you were referring.

  • Plotshred says:

    Also the point of fold might be better if it is off-set from the frame to allow space for the wheels to fold together flush.

    Right now the fold being in-line with the frame causes the inside of the tires to prevent the bike from completely folding.

    Since I’m talking about the folding, you might also consider the seat being in a location that it does not interfere with the handle bars.

    (Thinking about the way a bicycle moves when ridden) Consider having a competitive cyclist critique the design. They usually have the best knowledge of what the bikes need and how they are used.

  • Donald says:

    When can it be purchased? Do you live near Taichung?

  • semininja says:

    I have a few suggestions that might make this a bit more practical…

    In response to the complaints about hub-less wheels, there’s an easy solution: drop the forks so it contact the wheels at the ground, or points just forward and backward of that point. Remember those things from Star Wars: Episode III?

    Gearing complaints? Planetary gears are your friends. Fix the center ‘sun’ gear, and pedal-power the ‘planets’, and that brings up your drive gear’s speed quite a bit. If you bring the drive gear down to the ground contact point as well, you get much less strain on the wheel. This means that you’ll have to do some torque routing (i.e. chain), but it also permits you to move the back wheel a bit, opening out the wheelbase and creating more stability (not that there was much to worry about in the first place).

    Granted, this makes the appearance less minimalistic, but it makes this a viable concept.

    As far as the stance of the bike, it should be proportioned so that the rider’s leg is at a little less than full extension when they are sitting on the seat, not above it as in the graphic. It doesn’t need much, just to scale up the bike so that it fits in that respect. If you do that, the aerobars will also be far enough forward to allow for a more streamlined profile. If you allow for front-to-back adjustment of the bars, it will allow for more customization and comfort when riding.

    All in all, not great initial design, but it could be made practical without drastically changing the aesthetic.

  • Phil says:

    this bike rendering was intended to draw all the ME’s away from their FEA analysis and say,,, com’on IDman!!!
    beautiful lines, beautiful photorealistic rendering tool, but no way with current manufacturing…
    but what the hey,, they say sci-fa follows sci fi and this is definitely sci-fi
    ,,,,i get paid for sci-fa

  • Eric says:


  • Ben says:

    This looks stupid. There would be no advantage to this design and would actually face much more significant rolling resistance making it useless as a racing bike and more of a neato display piece

  • James says:

    This was my first thought too, surely it would ride up and probably topple over backwards?

  • Jimmy C says:

    Now, people, if you look closely, you can see that A) there are gears embedded in the back wheel itself, B) the front wheel is actually hooked into the “single point contact” and C) the wheel wells keep the bike wheels balanced. Any questions?

  • Mr. Green says:

    That is one of the coolest bikes I have ever seen. It is the bike the Jetsons would ride if they actually had roads.

  • Hello? Basic physics? says:

    Well, a) the gear ratio is appalling, b) we already knew that, but that’s not even close to the problem, and c) balanced? What are you even talking about?

  • Karl says:

    I liked your design, the use of plastics is ok, but they are structurally weaker than metals, so a plastic bike is bulkier but lighter than a chromemolly bike, the same way an aluminium bike is from said heavy bike.

    another poster has adressed the gearing issue quite well a possible solution is that of the lunartic bike, the pedals move a gearing that revs up the wheel.

    Einstein said that crazines is to do the same thing and expect different results, and Edison said “I haven’t failed, I discovered 10000 ways it won’t work”, so you are up in a good path. forget about standard forks, gear ratios and the like and play with what is left, you will find ten thousand ways it won’t work, but when you find the one that does it…

  • JJR2 says:

    There’s no reason it would *have* to be single-speed. The value of the necessary “cleverness” would depend on the market—if there is one. Most of the design could probably be made to work, if the priority is aesthetics more than robust, simple function.

  • MiG says:

    Yes, I only have one question: are you another artist without education in the physical sciences?

  • MiG says:

    Sorry, the threading has broken down. My reply is to Jimmy C asking “Any questions?”.

  • sskx says:

    Awesome simple green design but don’t be a problem to urself tring to reinvent physics.
    The rail/magnetic design would never work under 10^x$ | x > 4, not to speak about the time it would take to make it reliable. Take one step at a time so you won’t fall from the start.

  • Silvestri says:

    I did not get a chance to read all of the comments, but a possible solution to some of the common concerns I’ve seen (seat to close to back wheel/not really a racing bike with one gear) first to solve the center of gravity issue, perhaps a design which has the seat slide up the frame, then locking into place could be a decent compromise. It is positioned so someone leaning forward (as in a racing design) can have their center of mass in an ideal location, so this would be more for a user’s preference. The functionality is still there, and you considerations, Allen, are very thought through. As for the gearing issue, perhaps including a gearing design strictly on the pedals? I’ve just now heard of this design, so I haven’t drawn anything up, but It seems you could adjust the gearing directly from the pedals, and perhaps in this way achieve the effect some of those concerned with gears would wish to see.

    I have to say, my grammatical skills are not the best, but if you would like any input at all on this bike, I would be happy to work on this.

    The point of contact on the front wheel is most likely my biggest concern though, but for what you are trying to accomplish, I think this is a good start. It has a ways to go before it could be considered a “racing bike”, but a portable bike that doesn’t go slow is still something people would want, and the looks are a plus as well.

  • Beautiful design. I would love to see this as a high-wheeler concept. The minimalist, elegant aesthetic would look stunning as an ultra-futurist penny-farthing design. A major engineering challenge would be designing the gearing inside the pedal assembly to give a proper mechanical advantage.

  • failian says:

    let me add upon this

    no dampening of motion might make your crotch, legs, hips and spine to get some of the most horrible pain ever experienced by mankind.

    then, even if therer are a lot of rails with moving balls on the top of the frame it will wobble. and get teared to pieces really quick, it can get dirt in there getting slowing and sudden stop leading your head towards the earth,

    so much more going on, better simulate it on a less than perfectly clean and even testing ground.

  • bellylint says:

    Concept bike where the concept fails. The mechanical disadvantages created at the wheel connection/gear points render these connections incredible in the true sense of the word – as in not credible.

  • Cool , Love to have it

  • del mundo says:

    It’s obvious this “designer” (stretch of the word) has no real understanding of the physics of a bicycle with a rider on it. I’d like to see how easy it would be to keep that front wheel on the ground when your butt is behind the center point of the rear wheel. Not to mention how squirrely a bike with such a ridiculously short wheel base would handle.

    As an architect, furniture designer and national caliber bicycle racer, I’m appalled that students design crap like this that looks “cool” but has zero relationship to the reality of the human form and the physics involved in designing such a machine that we need to be able to ride. I’m all for “thinking outside of the box” and love minimal and modern design but get your head out of the clouds and get grounded with basic physics and rider position before you post something this insane on the internet and make a fool of yourself in the design AND cycling community

    It’s just not about making a “thing”. Where was your research? Did you interview ONE experienced frame builder? Did you analyze current bike geometry and rider positioning? Did you find any gaps in those currently used that your freaky position corrects? Do you have idea of how that trail is going to make the bike steer? Do you even know what trail is? Did you position one humanoid on your model to see if it would tip backwards? Did you overlay the current relationship of rider and his contact point of saddle, pedals and handlebars to a known current stable, power-efficient bike geometry and do something BETTER in that regard? You’re the epitome of the “disconnected” designer who does it in a vacuum and thinks they did something “cool”. And like a vacuum, this sucks as a bike.

  • GestA4F says:

    Hrm. This post didn’t reply “inline” with PLR’s post that begins with
    “Stupidest thing I have ever seen. The bicycle is a perfect machine….”
    Apologies for the errant reply!

  • 1st,I’m shocked by this bike design,cool and fantanstic!
    2nd,I want to buy a bike like this though I don’t konw whether this design is safe enough? I’d like to own it!

  • sebastien says:

    i know it’s late comment, i someone just sent me this, the main problem with your design is that the wheel base is not wide enough, the rider will be sitting too far back on the rear wheel and turn your bike into a perpetual “wheelie”. as soon as you will put a lot of power on the pedals, the front wheel is going to take off as well as the rider’s gravity center is too far back on the bike. you can solve the problem by moving back the rear wheel thus giving the bicycle greater wheelbase.
    Sebastien, designer & ex-bike racer.

  • Where can we find videos or, at the very least, photos of people actually RIDING this concept bike?

  • Hi Allan,

    If you’re still reading comments on this post, I just want to add that I love the concept drawing, especially the fact that this is a foldable full size bike. I’m not interested in it being a racing bike, but for city dwellers, without a chain, and spokeless wheels that make it easier to clean, this design would be a wonderful invention. Fix up the problems mentioned by some of the more knowledgeable commenters, and then create a mockup and demonstrate the bike in a city setting such as Amsterdam and I think you’ll be onto a winner.

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