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Designing a three wheeler

  1. Feb 17, 2005 #1

    wolram

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    A front wheel driven trike to be exact, how would i start designing
    the suspension geometry, i have in mind an ultra light vehicle
    driven by the most economical engine "within reason", and street
    legal, maximum speed 70 mph, to carry two persons with some
    comfort. the driven wheels would be at front of the vehicle.
     
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  3. Feb 17, 2005 #2

    brewnog

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    I assume then that your single wheel would be trailing?

    Designs which spring to mind are the Messerschmitt bubble car and the Morgan three-wheeler, both are outdated (and the Morgan was rear wheel drive) but fit the bill of lightweight, two seater, three-wheelers, perhaps you want to do some research?
     
  4. Feb 18, 2005 #3

    wolram

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    Brewnog
    yes i do need to do some research, i though i would start with wheel geometry
    and suspension, i want to keep on the lines of a morgan, but with modern
    parts.But what is the best way to research 3 wheeler wheel geometry?
     
  5. Feb 18, 2005 #4

    brewnog

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    I reckon it would be pretty hard to start from scratch (especially trying to prove to the SVA man that your own steering and suspension designs were safe), but there are plenty of kits around for this kind of thing. I met a guy who was building one based on a Citroen 2CV, but it looked amazing! I think it was probably a Pembleton (http://www.pembleton.co.uk), it wouldn't be too hard to incorporate more modern components.
     
  6. Feb 18, 2005 #5
    You may want to check local laws...

    Three wheelers of ANY kind are not street legal in some US states (which I found out by being pulled over on a back road).

    Cheers...
     
  7. Feb 18, 2005 #6

    brewnog

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    Three wheelers are relatively common here, just because it's got three wheels won't exempt him from being able to get street-legal status. However, he will need to take and pass a single vehicle approval (SVA) test, which covers things like weld quality, curvature radii on exterior fittings, light positioning etc.
     
  8. Feb 18, 2005 #7

    wolram

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    brewnog
    i want to build something that is practical and economical for short trips
    ie, to the supermarket, it will not have to have stunning performance, but
    must have good economy, and a 70 mph maximum speed, the reason
    for three wheels is taxation .
     
  9. Feb 19, 2005 #8

    brewnog

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    Well are you intent on building it from scratch? Most of the kits allow pretty cheap building of some really lightweight (and hence 50mpg upwards is usual) vehicles, and obviously you can tailor them to suit your needs. Building a car from scratch involves a lot of hard work, and is much harder than it was, say, ten years ago before the mandatory SVA test.
     
  10. Feb 19, 2005 #9
    wolram,

    I have a brother-in-law that does this with a freind of his and I have had the pleasure of playing with one of these beasts. A lot of trikes are built using old VW bugs that are chopped up and rigged to be a trike. So you may want to look into that, of course you can use just about any vehicle that has the engine in the rear. These toys can be quite elaborate and really cool!:biggrin:

    Have a look at this site:

    Brothers of the Third Wheel

    They have a forum and may be able to help you out! Plus a lot of other goodies like photos, links, etc. When my bro-in-law was showing of the stuff they had built he showed me the site.
     
  11. Feb 20, 2005 #10

    wolram

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    Thats a great site Polyb, lots of photos and info, but my three
    wheeler is going to have the two wheels at the front, i have found
    loads of info on the web, should keep me busy for a while, thanks
    all for advice.
     
  12. Feb 28, 2005 #11

    ohwilleke

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    Motorcycles with a sidecar are quite fuel efficient, and while not exactly in your mandate, have the virtue of greatly reducing insurance costs because the historical records is that motorcycles with sidecars are in fewer accidents than four wheel cars. In contrast, three wheel trikes have a very bad historical accident record (because reckless people tend to drive them) and thus might have very high insurance costs.
     
  13. Feb 28, 2005 #12

    wolram

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    Ohwilleke
    Me reckless, perish the thought.
    :rofl: 70 mph is my max from now on, and as i hate to give
    government my hard earned sterling frugality is the priority.
     
  14. Feb 28, 2005 #13

    Cliff_J

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    Here's a little more info for you that you may not have run across yet:
    http://www.rqriley.com/3-wheel.htm

    Kinda funny looking but the Tri-Magnum plans they sell is all about taking an old motorcycle and using it as the back third wheel with the passenger comparment supported by the front two wheels.

    The thing I never cared for on my 3 wheeled ATV (Yamaha 250 Tri-Z) was that the one small front tire didn't have enough traction to turn on slippery surfaces, was too light and wheelied a lot, and didn't have enough floatation on very soft surfaces. A Yamaha 350 Banshee 4 wheeled ATV fixes all those problems...
     
  15. Feb 28, 2005 #14
    When I was down in San Francisco we rented these crazy two person go carts that had two front wheels and one back wheel. It had to have "training" wheels because everytime you turned semi fast of course it would try and tip. It was fun to mess around in but I certainly wouldn't want one on a long term basis. I think the main problem is the fact its just plain dangerous to drive around something as small as a go-cart.
     
  16. Dec 15, 2006 #15
    Hi, May I suggest that you employ a two wheels forward and a single wheel aft
    configuration. The Major problem with single up front is that in a braking turn,
    this design tends to dump the vehicle over quite easily. Where as the two wheels forward is quite stable. The three wheeled Morgan is a spactacular
    performer in this regard. Read up.
    Try www.3wheelers.com and look for the ones with two wheels forward.
    These are the superior designs.
    Also, there is recent development in what is called a "Leaning Trike". Give this a google and you shall see some remarkable designs, in that the bady leans toward the inside of the turn, making a most stable vehicle indeed.
    The trick is in the driven wheels..or wheel.
    These are interesting sites to visit. Press on,Sir.
    Best regards, Dan
     
  17. Dec 16, 2006 #16

    Danger

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    Wouldn't do you much good in England, but in Canada there's another serious advantage to the 2 in front and 1 behind wheel system. In winter, you can replace the front wheels with skis and put a honking studded mud tire on the back. :biggrin:
     
  18. Dec 19, 2006 #17
    Hi, You can always put two skis up front and a big balloon stud tire in back.
    Than ya can say"G'day!" . :)
    It's all about the weight, and power required.
    Best regards, Dan
     
  19. Dec 20, 2006 #18

    Danger

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    I still prefer the mud jobs, because our situation changes constantly. There is a saying here that if you don't like the weather, wait a minute. Balloon tires are a bit too special-purpose, whereas the Trailblazers on my Camino are good on a clear highway as well as climbing out of mudbogs. It's a lot easier to carry a couple of spare 'cycle tires to swap in for the skis than it is to also carry a spare rear wheel assembly.
     
  20. Jan 30, 2007 #19

    AlephZero

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    See http://www.mp3.piaggio.com/

    Does 3 wheels, 78 mph and 70 mpg meet your spec?
     
  21. Jan 31, 2007 #20
    Hi, Interesting configuration. If I could spread the front wheels by a foot, and get a single nose wheel leg through the middle, I'd have something I could fly with. I'll have to find one that I can look at up close.
    Thanks for the link.
    Best regards, Dan
     
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