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  1. shedfire says

    Does this designer have any concept of bicycle steering dynamics, and the effects of head angle, fork rake, trail?

    • Richard Masoner says

      I like the origami idea, but I’ll be amazed if it’s actually ridable.

      • shedfire says

        “his folding bike concept based on central headset position”

        The problem with this, is that this is a flawed concept. Fail.

  2. Juliano Pappalardo says

    for sure, riding this prototype is different from anything else.
    I can not asure that it is unrideable. But I must admit that the idea is original, never seen before (the folding axis is the steering axis)

    • shedfire says

      There are bikes at the circus that people can ride, where the handlebars make the forks turn the opposite way. This bike has a 90deg head angle and -ve trail of around 350mm. Typically bikes have positive trail of around 50-80mm. It’s crackers.

      • Andrew says

        So give it a <70 degree headtube angle so that it's steering geometry more closely mirrors a standard bike, and readjust the frame a bit to accommodate the new fold angle.

        The concept as presently imagined isn't workable, but that says nothing about its potential. Maybe it's a design dead-end, but you clearly haven't done enough thinking in your snap judgement to say that definitively.

        A little imagination is important, sometimes.

        • Juliano says

          I like DESIGN because It´s about what we´re doing here, turning imagination into something real.
          I simply hope mr. Saul Maret is seeing this.

          • Atomic says

            I can IMAGINE a bike with a frame made out of pasta with pizza wheels. Your knowledge of the physical properties of thos materials tell you it’s a silly idea. If you had knowledge of bicycle dynamics you could see that this concept is just as silly. Imagination is not design nor vice versa. One might feed the other, but not necessarily. Btw, this central steering postion is seen in digital renderings several times each year. You’ll not see a ridable prototype, because it’s at that stage the designers realize it’s unworkable.

            Personally I think a bicycle blog should not repost these renderings which so are so strikingly ignorant of the laws of physics (front wheel behind handlebars anyone?) but maybe that’s just me.

          • James T says

            “Personally I think a bicycle blog should not repost these renderings which so are so strikingly ignorant of the laws of physics”

            I like to post all kinds of different concepts here, and I certainly acknowledge that some are more realistic than others. I don’t expect anyone to appreciate them all, but I usually can find at least one interesting detail or design element in even the most flawed concepts. If nothing else, the designs are a springboard for discussion, which is what this blog (or any blog for that matter) is all about.

            Sometimes I comment on the designs I post, and other times I just put them out there to allow readers to react. In either case though, discussion and critique from readers are always welcome and the designer stands to benefit from that interaction.

  3. baconqurlyq says

    I wouldn’t call a fixie ridable, but many people enjoy them. Who knows what application this bike would have, but I admire it when people let their brains go nuts and do something even if people might scoff.

    • Richard Masoner says

      @Bacon: By “unridable” what I mean is that fundamentally this bike cannot stay upright while in motion. A bicycle in motion is stable due partly to the caster effect — the bike’s motion keeps the wheel in front of the bike, and this is a function of the wheel’s position in relation to the steering pivot.

      With the crazy origami design show here, the wheel wants to flip towards the back of the bike, like a broken wobbly wheel on a shopping cart, and down you go before you can say “physics.”

      Bicycle dynamics isn’t intuitive, but bike designers had figured this stuff out through trial and error (on fixed gear bicycles no less) by about the mid 1880s.

  4. Juliano says

    Yes, intuitively the frame would fold when not desirable, I thought in locking this axis before riding and steering in a manner similar to the Bimota Tesi motorcycle design, check out!
    Sorry about my English
    :)

    • shedfire says

      Bimota Tesi uses hub centre steering. This doesn’t. You’re English is great.

  5. Sabinna says

    “We have to work out what to do by thinking through the possibilities in ways that are simultaneously imaginative and realistic, and not less imaginative when more realistic.” http://nyti.ms/cfni0e

  6. Don says

    Innovation is easy when you do not have to make it work.

  7. Paul Wujek says

    It looks like the pedals will hit the front fork on tight turns, although this could be alleviated by making the fork angle downward from higher up. The problem with the position of the front wheel, behind the handle bars, would still exist, but maybe the wheel could be moved more forward. Hinging in the middle is going to make for a very weird steering feel, and balance.

  8. Milessio says

    Yes, a computer render is now easy to produce and looks good, so is now not worth much more than a hand drawn sketch. A working rig needs to be tested before a design can be serious option . . . .

    But, a one line put-down is easy too. And the design might work with fine tuning.

    ‘the reason we use the angles we do is less to do with steering dynamics than ergonomics’ p34 Bicycle Design by Mike Burrows.

  9. mommus says

    Imagine trying to take a bend on this thing. The crazy fork angle will make the whole bike bend in half while you’re riding. you’d also need to lean right over to steer it at low speed, as the handlebars would travel around a radius centred on the folding joint/head tube. The pedal arms are also too short and it doesn’t exactly fold up small does it!
    It’s different, I’ll grant the designer that… the detailing is very nice, and it’s brave to have continued the design from the first concept, but surely he/she could have seen that this bicycle won’t be rideable. The simple action of pedalling will cause the frame to wobble left and right as there’s no rigid structure beyond the bottom bracket.
    Severe fork angles seem as ubiquitous as hubless wheels in current concept designs. Ho hum.

  10. trackasaurus says

    SHEDFIRE needs to stop yapping. The only FAIL I see here is an armchair analyst trying to choke a young designer by the throat for a thought process. Ever heard of constructive criticism mate?

    • shedfire says

      I don’t think off-the-wall, unrideable creations should be applauded. It’s a stupid design that fails on many points and shows a huge lack of understanding by the “designer”.
      Saul should get out of his design studio and into his shed and start seeing how things work, rather than doing ludicrous sketches.

      • Richard Masoner says

        @Track: Bike designers figured out about 130 years ago that placing the wheel in front of the pivot point results in an unstable bike. That’s experience, not armchair analysis.

  11. mommus says

    @trackasaurus surely pointing out a flawed thought process IS constructive criticism?

  12. Al says

    Not too bad. This means, we are all paying attention to the bike evolution, the evolution of our baby, the bike, that is. I love them too, and I welcome good imanition. As an experienced designer, I can tell you this; every idea starts somewhere. This idea belongs in a blog, yes indeed, all we are doing is a design review, analyzing, studying a concept, NO NEED to put down.
    I encourage people to do just this, just let you are ideas and dreams out, is all good.
    Think about the plane or the flying idea, how many crazy concepts many inventors, designers, entrepreneurs and engineers came out with and how many people, engineers and physicist laugh and put down the concept? Look where the idea is today. So, lets all participate an a critic forum in a constructive way, letting Saul know of the improvements he need to make and the engineering details he missed. That is all I have to say.

  13. smalghan says

    If the lower arm curved over the top of the front wheel and held a short fork that the wheel mounts to then that would go a long way towards making the steering geometry more rideable. Cables hidden inside the frame tubes connecting the handlebars to the fork crown would control steering motion. It could still look pretty clean and simple while riding a lot more like people expect a bike to feel.

  14. Shozo, Keizo and Yoshizo says

    I think a visit with Dr. Alex Moulton would be educational for neophite bicycle designers (and some posters here). He could take them to his office and show 55 years worth of design sketches…and then take them out to the shed and exhibit 55 years of tested prototypes.

    Unless a designer has demonstrated reduction to practice, they should expect peer review to be, shall we say, “harsh”.

Continuing the Discussion

  1. Le Pliable Folding Bike | Bike Reviews linked to this post on August 25, 2010

    [...] you to “…push it around like a golf caddy” very much like that of a folded Stirva. Source: BicycleDesign August 24th, 2010 / No Comment|Concept Bike / Le PliableRelated Posts :Bigfish Folding BikeToyota x [...]



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