A bicycle can cut friction in half, called "Half Bicycle"

Discussion in 'Cycling Equipment' started by iwico, Oct 2, 2008.

  1. iwico

    iwico New Member

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    A bicycle can cut friction in half by moving centre of gravity

    People like bicycle, do not like tricycle or quadracycle--4 wheels bike, because on bicycle only two wheels touch the ground, also is easy and safe to be ridden.

    Ideally cyclist should like to ride a unicycle, because friction only existed between one wheel and the ground (cut friction in half compare with on a bicycle), but ride a unicycle need special skills and not safe.

    Based on a normal bicycle, this "Half Bicycle" modified some parts: Cyclist’s set is moved backward (also hand-bar is extended backward), to make sure centre of gravity of the bicycle is around on back wheel B.

    Cyclist can ride this bicycle as a normal bicycle by moving centre of gravity toward front. If road condition is good, cyclist want to increase speed, he can move centre of gravity backward little bit and make sure the centre of gravity is on back wheel B. At the same time, front wheel A will be left from the ground, the bicycle becomes a unicycle, only wheel B touches the ground. This means friction between wheels and the ground is cut in half. In other words this bicycle only needs half amount of human power to travel in same speed (or same distance) as a normal bicycle.

    More details and picures on www.freelights.co.uk/bike.html

    Regards
    Mr Q Gang
     
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  2. scuppy

    scuppy New Member

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    - Halving wheel to ground friction does not halve energy required to pedal bike
    - Ground to wheel is not the only source of friction
    - Ground to wheel friction isnt even an impediment, actually without it you'd spin in place
    - Air resistance accounts for much more impediment than friction in other parts of the system
     
  3. jhuskey

    jhuskey Moderator

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    Ageed that air resistance is a big factor but don't forget gravity.
     
  4. 531Aussie

    531Aussie Well-Known Member

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    Could be worse: at least your spam is bike related :p
     
  5. iwico

    iwico New Member

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    1. If as you said the friction between wheels and the ground is not important, why people do not ride tricycle or 4 wheels bike? they are much safe and steady.

    2. I means cut the wheels' friction with the ground in half. Friction with air is always existed, it does not effect with wheels' friction. If in same air friction condition, this "Half Bicycle" still cute wheel friction in half, isn't it?

    Regards
    iwico
     
  6. dhk2

    dhk2 Active Member

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    1. Trikes and four wheel bikes really aren't safer. In fact, it's very difficult and dangerous for trikes to attempt to keep up with bikes on a twisty descent. Also, the "extra" wheels are heavier, require more structure, and have more wind resistance.

    2. Based on decades of test data, tire rolling resistance is generally taken to be a small fixed coefficient (eg, .005) times the load on the wheel. Based on this accepted model, having one wheel carry double the load would produce no significant change in rolling resistance.
     
  7. kdelong

    kdelong Well-Known Member

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    One very important question, how do you steer this bike? If the front tire is off the ground, you cannot steer. Leaning into a turn is not possible on only one wheel. Friction, and a good deal of it, is required to be able to turn.

    The main reason people do not ride a trike or a quad on the road has to do with the width of the bike. It is too wide to ride on the road safely, and in some localities, they are illegal due to this fact. You can find a large number of trikes on our local bike paths, just not on the road.
     
  8. artemidorus

    artemidorus New Member

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    The major resistance faced by a human-powered vehicle is air resistance. This is overcome most importantly by good body position such as with a recumbent bicycle or with a good time trial position. Your invention has the cyclist sitting bolt upright, which is the worst possible position. Even an XC mountain bike with fat knobbly tyres would be faster than your proposal (if it ever were to work, which seems unlikely), as the XC MTB tends to put the rider in a reasonably aerodynamic position.
     
  9. artemidorus

    artemidorus New Member

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    Oh, and I like the "no drag" lighting system on your website. You really should publish in "Nature" or "Science"! That's Nobel Prize material. We'll be able to send rockets to Mars with that technology.
     
  10. RedRider2009

    RedRider2009 New Member

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    I think I read somewhere that wind resistance accounts for 90% of the resistance on a bicycle. I suppose that as speed increases though, the stats would change.

    ohhh...h/o I think it was that 90% of wind resistance was on the rider, and the other 10% was resistance on the bicycle
     
  11. Akadat

    Akadat New Member

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    All the weight on one wheel, or half the weight on each of two wheels? I think the difference in efficiency will be the viscosity of grease in one bearing, which will be less than if you had a drink of water before the ride or not! The weight of the third wheel in the picture will cancel out any gain in efficiency even if you manage to ride on one wheel.

    If races are won using your system then everybody will believe it.:)
     
  12. jhuskey

    jhuskey Moderator

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    All these figures seem to be based on flat terrain. I live in the mountains and consider gravity a big factor.
     
  13. iwico

    iwico New Member

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    Hi

    Ask any cyclist: If bicycle's tyres are little bit flat (means the area touch the ground little bit larger), cyclist will feel much friction (much heavy). This why we always have to make sure the air in tubes of the wheels are full to reduce the friction. Wheels friction with the ground are important.

    In my mind, the back wheel of this "half bicycle" must be made in very good quality, with good strong tyre and good brake. If the tyre (on back wheel B) is fully aired, it can reduce friction (although all weight is on it).

    Regards
    Q Gang
     
  14. iwico

    iwico New Member

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    Answers:

    1. As my webpage says: When road condition is good, and the bicycle is in straight direction, at these conditions, cyclist can turn the bicycle to unicycle. If they need turn direction, they can move centre of gravity toward little bit, front wheel touchs the grount to turn direction. Remember, the front wheel only need to be left from the ground very little (1mm or even 0.5mm), just off the ground will enough.

    2. In fact, if a cyclist is good on unicycle after some practise, they will be able to turn. You see people ride unicycle, they do turn.

    3. Just like people cannot ride a bicycle at start, after some practise they can do it. By using this "Half bicycle", they too need some practise to ride.

    Regards
    Mr Q Gang
     
  15. iwico

    iwico New Member

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    Hi

    1. First, we do not talk about wind resistance here.

    2. wind resistance is not alway add friction, if you travel in same direction of wind, you may get extra power from the wind.

    Regards
    Mr Q Gang
     
  16. iwico

    iwico New Member

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    Hi

    If the back wheel's tube is fully aired it can hold full weight of bicycle.

    Regards
    Mr Q Gang
     
  17. dgregory57

    dgregory57 New Member

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    People have been able to ride wheelies for years, and in fact, isn't there a racer known for pulling a wheelie once in a while for fun? Someone who raced professionally some time in the past several years, and may still race... It seems that I have seen a video of someone doing it at the finish of a pro race.

    So, what exactly are you adding to what someone can do by riding a wheelie?

    And I agree that a wheelie bar does nothing but add weight... even if you add a fancy name to it. They had them for stingray type bikes in the 70's.

    [​IMG]

    And if riding a wheelie is most efficient, don't you think that the professionals would be doing it? After all, they have dynomometers (sp) and wind tunnels to test all of the possibilities for gaining efficiency.
     
  18. dgregory57

    dgregory57 New Member

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    Oh, here is a cyclocrosser doing a wheelie...

    [​IMG]

    No wheelie bar needed. [​IMG]
     
  19. alienator

    alienator Well-Known Member

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    This absolutely will not work.
    • You cannot just ignore aero drag. It's a huge component.
    • A tailwind doesn't "add" power like you think.
    • Your idea will be incredibly heavy. A system that "changes" a bikes center of mass? By the very definition of COM on a bike rider system, any significant change in COM will require a significant increase in mass or a huge change in position. The first piles on weight. The second dramatically increases instability.
    • Having a system that actually alters the COM will be very complex, especially when you consider that system will have to be able to cope with a large variance in rider weight and rider COM. It will have to be well damped in its mechanical motion, and it will have to have a high degree of relative stability. Without a massive weight or an extreme position of an additional weight, a balance point for your system will still be ~45 degrees, give or take few degrees. That position is hardly stable at all. In fact it requires active control to remain stable.
    • Raising the bike's front end will limit how much of his or her surroundings a cyclist can survey. The cyclist won't be able to look as far behind without upsetting the balance on their barely balanced apple cart.
    • The idea would be absolutely dangerous and would have a dramatically reduced ability to execute panic stops or accident avoidance maneuvers.
    Those are just a few of the problems. You need to google "Rube Goldberg."
     
  20. artemidorus

    artemidorus New Member

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    McEwen
     
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