Fairings?

Discussion in 'Performance Mods' started by KiDD, Apr 12, 2008.

  1. KiDD

    KiDD Member

    Has anyone fabricated a fairing for their motored bike?
    I assume someone seeking increases in MPG and/or speed would have tried this.
    Any pics?
     

  2. Alaskavan

    Alaskavan Guest

    I didn't fabricate it.

    I have a Windwrap GX on the trike. Too early to tell if it makes much difference. I'll test for variation in mileage this summer. Pretty hard to determine the difference between 125 and 126 mpg.
     
    Last edited by a moderator: Apr 13, 2008
  3. eltatertoto

    eltatertoto Guest

    up here we call em cow catchers. ive never built one, but instaled one on a harley. augi gave me the idea to put somthin in my bars. i plan to do that this summer.fairing can be seen in my avatar, but is fairly common. but not o an 86 softail what that one is on.
     
  4. fastboy9

    fastboy9 Member

    If you really want a speed machine then fairings really are the way to go! check this video out http://www.youtube.com/watch?v=6FAzcEPMi14 Shows just a few of the worlds fastest bikes. speeds of up to 70mph, now think what it could do with an engine
     
  5. fastboy9

    fastboy9 Member

  6. augidog

    augidog Banned

    nice link...i think i can make use of some of that info...thanks :cool:
     
  7. fastboy9

    fastboy9 Member

    glad to be of help! ;), the human powered land speed record is around 70mph with a streamlined fairing recumbent. Now imagine that with a tuned tanaka on it! I'm sure you'll get your 50mph!
     
  8. Snax

    Snax Member

    If one's focus is to improve speed and distance, I think a more effective place to start on a bike is by cleaning up the wake of the rider with a rear fairing. The frontal area of the bike itself is relatively small, and the frontal area of the rider tends toward a rounded shape, but it's the turbulence off the backside that is largest and really slows a person down.

    Put another way, an object with low turbulence has low drag, and frontal area is rarely the largest contributor to it. E.g., a brick with only a nose-cone will never have as low a drag as a brick with only a smooth tapered tail-cone.
     
  9. sparky

    sparky Active Member

    But how would you add a tail-cone to a bike? ... especially in such a fashion that you wouldn't be able to just go ahead and make a front fairing as well?
     
  10. augidog

    augidog Banned

    yup, seems to me that a rear cone without a full streamliner would just be a "scoop"...

    imo - when it comes to the vehicle class "bicycle", streamlining is an all-or-none consideration, 'bents being the exception as easily streamlined with a fairing. my lil windshield experiments are great for weather protection, but pretty much useless aerodynamically. i bet my final version is not far from the bike as pictured in my avatar.

    but - a full streamliner on a 40-48cc setup would make a good showing in the 50cc motorcycle class...some of these new engines are astounding.
     
    Last edited: May 3, 2008
  11. Snax

    Snax Member

    I suppose it was more of a food for thought suggestion, although it would be easier to implement an effective one on a recumbent. And no, it's not a scoop if you cover the forward surface of it. Regardless, my point is that focusing on the front without attention to the rear would be ignoring more than half the problem aerodynamically.
     
  12. augidog

    augidog Banned

    agreed...and agreed...my lil joke was only a joke. i was playing with paint shop pro and each half always seemed incomplete without the other, the rear section-only always came out looking like more impedence than benefit.

    i think that as the competitive aspect grows, we'll see 'bents dominating the land-speed events.
     
  13. RATRODER

    RATRODER Guest

  14. Zev0

    Zev0 Member

    Would it not help if you used those aerodynamic wheel covers?
     
  15. Snax

    Snax Member

    I suspect that for that record, aerodynamic aids for the bike were not allowed. Regardless, I don't think the wheel covers are really all that effective on a bike. Having them on the front is just wishing for calamity, and the airflow over the rear wheel is already so spoiled by turbulence, the reduction in drag is likely very little without matching the width of the tire precisely to the width of the rim. Bladed spokes are nearly as effective from tests I read long ago.
     
  16. Zev0

    Zev0 Member

    Hmmm odd. Wonder why all the professional racers use them? Their MUST be something gained from them. Ever watch the Tour de France? They all use them. Of course they pedal instead of motor, but their must be some advantage.
     
  17. smitty

    smitty Guest

    Did you notice the fins on the backs of his lower legs?
     
  18. skyl4rk

    skyl4rk Guest

    If you get the software here:

    http://www.carlsondesign.com/#Fun_Shareware

    You can use the software to design fairings. The software is intended for designing boat hulls out of plywood. You can use a mouse to move curves around and make a chine boat shape (chine is the corner where two pieces of plywood meet on a boat). The software then calculates the shapes of flat panels to cut out and gives you offsets, so that when you stitch the cut outs together, will give the 3d shape you designed. The software takes a little getting used to but once you figure it out it does not take long to get a set of offsets to plot out on your panels.

    Design a fairing with the right dimensions for your bike, get the offsets, plot it out on some coroplast (?) sign material, cut it out and stitch it together with zip ties. Fit it over the bike, and cut the fairing behind the rider position to make a tail box. Use some aluminum bar or conduit to make a simple frame. Put the front half on a hinge at the front so you can lift it to get in or out. Make a place for the back half of the fairing front to drop into to lock it into place. Personally I prefer wind in the face so I would make a small hole in the top for my head to stick out. Its not as streamlined but it will be much, much faster than a non streamlined bike.

    I have not made one yet but if I get a recumbent I will be making a cloroplast fairing.
     
  19. Snax

    Snax Member

    I've often thought that a similar fairing on a un'bent rider's back might work as well.
     
  20. skyl4rk

    skyl4rk Guest

    Attached is a drawing of a fairing I designed using the Hull Designer software, for my dad's Bike-E, which is a fairly short wheelbase recumbent. The widest part is right at the riders shoulders, you have to imagine the riders head and helmet above the top of the fairing. The fairing was never built.

    The fairing looks a little odd because it is so short. The fairing is actually a fairly tight fit around the rider. It is not the best streamline shape, however it would be a big improvement over no fairing at all.

    It would be made of aluminum frame, coroplast and zip ties. This fairing could be built for less than $100, maybe less than $50 if you use stuff from your junk drawer. By bending the coroplast into shape and tying it together, the fairing would be stiff. The ribs in the coroplast would have to be across the short dimension of the panels, so the panels would bend correctly.
     

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