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Thread: Aerodynamic fairings for motorcycles

  1. #1
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    Default Aerodynamic fairings for motorcycles

    I'm considering a project , a diesel powered motorcycle that would be capable of 200 mpg (Imperial ) or US 166 mpg.A cruising speed of around 55mph .Some weather protection .





    Aerodynamic fairings for motorcycles , especially ones that can pass NSW State registration (very strict ) ,are extremely difficult to design .This is a Dreamliner designed by the Royal Enfield factory in the early 50s .It is surprisingly effective for such a bulky object . Here are the figures from the original road tests as fitted to a 350 Royal Enfield .A 25% decrease in fuel consumption and a 10mph increase in top speed on a 13hp bike.The diesel would have 10hp.



    It was a reasonable job built at the time of the dustbin race fairings and with WW2 aeroplane
    ideas in mind .This graph is the wind resistance of a normal bike , pretty similar to a brick.



    Does anyone have any ideas on this subject ? Photos , information .

    Thanks all .
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    Default Re: Aerodynamic fairings for motorcycles

    This one is amazing and extremely efficient but would not be registerable in this state .
    http://www.velomobiel.nl/allert/Recu...0motorbike.htm
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    Default Re: Aerodynamic fairings for motorcycles

    Yeah ,it's marvellous isn't it ? He gets 80mph and 200 mpg from a 125 Honda .
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    Default Re: Aerodynamic fairings for motorcycles

    It should be a fun project.... but gawd I hate fibreglass.

    Peter, I'm still working under the assumption you want the Postie bike? I'm bringing it up on the trailer on Friday to Byron Bay
    "Travel is fatal to prejudice, bigotry and narrow-mindedness, and many of our people need it sorely on these accounts. Broad, wholesome and charitable views of men and things cannot be acquired by vegetating in one little corner of the earth all one's lifetime" Mark Twain... so... Carpe the living sh!t out of the Diem

    I'd rather look back at my life and say "I can't believe I did that" instead of being there saying "I wish I'd done that"

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    Default Re: Aerodynamic fairings for motorcycles

    Quote Originally Posted by The Bigfella View Post
    It should be a fun project.... but gawd I hate fibreglass.

    Peter, I'm still working under the assumption you want the Postie bike? I'm bringing it up on the trailer on Friday to Byron Bay
    Yes I do Ian ,it may be modifiable and then registerable in Qld .It's a bit of a long shot but Qld is pretty flexible when it comes to registration of specials .The diesel is the preferred route but the postie may end up being the way it goes .
    Do you by any chance have another front wheel for a postie ?
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    Default Re: Aerodynamic fairings for motorcycles

    Quote Originally Posted by Norman Bernstein View Post
    Why would it not be registerable in your state?
    The seating position has been changed to a radical feet forward to reduce the frontal area ...which is the first and smartest thing to do in this case , but our state absolutely HATES any modification from standard specs .
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    Default Re: Aerodynamic fairings for motorcycles

    Hello ? there must be some expertise on aerodynamics here ? Someone ?
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    Default Re: Aerodynamic fairings for motorcycles

    Actually, they aren't bad with bikes. Cars are different. There's something on the myrta website if you search for motorcycle modifications. They are mainly concerned with handlebar positions.... all about getting rid of apehangers.
    "Travel is fatal to prejudice, bigotry and narrow-mindedness, and many of our people need it sorely on these accounts. Broad, wholesome and charitable views of men and things cannot be acquired by vegetating in one little corner of the earth all one's lifetime" Mark Twain... so... Carpe the living sh!t out of the Diem

    I'd rather look back at my life and say "I can't believe I did that" instead of being there saying "I wish I'd done that"

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    Default Re: Aerodynamic fairings for motorcycles

    Bikes aerodynamics aren't bad ? No, they really horrible ! Look at the chart below .
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    Default Re: Aerodynamic fairings for motorcycles

    '' You ain't gonna learn what you don't want to know. ''
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    Default Re: Aerodynamic fairings for motorcycles

    Interesting idea. I think they would both be vulnerable to cross winds.
    There is nothing quite as permanent as a good temporary repair.

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    Default Re: Aerodynamic fairings for motorcycles

    This is good !!

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    Default Re: Aerodynamic fairings for motorcycles

    Quote Originally Posted by Stiletto View Post
    Interesting idea. I think they would both be vulnerable to cross winds.
    The little one is ,about 60 km is the limit for cross wind .

    As for the old Dreamliner , I chased up a reprint of an original test ride from 1957 .The Dreamliner was, despite it's appearance, very good in cross winds and as good as another unfaired bike on the same day . It had something to do with the concave shapes on the sides and the balance around the C of Effort / C of Balance ? Anyway it's more cunning than it appears .
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    Default Re: Aerodynamic fairings for motorcycles

    Quote Originally Posted by The Bigfella View Post
    Actually, they aren't bad with bikes. Cars are different. There's something on the myrta website if you search for motorcycle modifications. They are mainly concerned with handlebar positions.... all about getting rid of apehangers.
    OK ,I misunderstood ...RTA are OK with modifications .
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    Default Re: Aerodynamic fairings for motorcycles

    I have been thinking along these lines too, but not for a motorcycle but for my F150.
    It is such a brick that I have to assume there are ways to make it marginally better.

    Randy who won't go on and steal the thread

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    Default Re: Aerodynamic fairings for motorcycles

    Aerodynamic fairies on motorcycles?

    Jasus these are quare times. . .

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    Default Re: Aerodynamic fairings for motorcycles

    Peraves ecomobile....
    Someday, I'm going to settle down and be a grumpy old man.

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    Default Re: Aerodynamic fairings for motorcycles

    Quote Originally Posted by Stiletto View Post
    Interesting idea. I think they would both be vulnerable to cross winds.
    +1. I also think they would be prone to being sucked under an 18 wheeler trailer at speed, especially on a curve. Ok I guess around the city at low speed.

    regards,
    Waddie

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    Default Re: Aerodynamic fairings for motorcycles

    Waddie

    .
    Quote Originally Posted by PeterSibley View Post
    The little one is ,about 60 km is the limit for cross wind .

    As for the old Dreamliner , I chased up a reprint of an original test ride from 1957 .The Dreamliner was, despite it's appearance, very good in cross winds and as good as another unfaired bike on the same day . It had something to do with the concave shapes on the sides and the balance around the C of Effort / C of Balance ? Anyway it's more cunning than it appears .
    '' You ain't gonna learn what you don't want to know. ''
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    Default Re: Aerodynamic fairings for motorcycles

    3rd call for aerodynamics expertise .... come on fellas .Someone has got to know more than I've been able to chase up so far !
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    Default Re: Aerodynamic fairings for motorcycles

    Peter,
    I'm glad to hear the the Dreamliner handles well in crosswinds. I have a 640 lb unfaired bike that handles great on the highway and in crosswinds, but a couple years ago I was riding an almost fully faired lighter weight crusier type of bike and for the life of me right now I can't recall the make/model exactly, but in a light rain trying to pass an 18 wheeler I almost got sucked under that truck. This had never happened on my unfaired road bike. I still don't know if all fully faired bikes have this tendency. Just that the bikes you are working with have the most complete fairings I've ever seen.

    regards,
    Waddie

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    Default Re: Aerodynamic fairings for motorcycles

    I must admit ,I will be extremely careful of 18 wheelers , semis we call them .I usually ride back roads sans heavy trucks .
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    Default Re: Aerodynamic fairings for motorcycles

    There was the similar concept English Quantum, which never went anywhere.

    At a lesser scale, Charlie Perethian at Parabellum has been producing wind-cheating windshields and such for motorcycles for decades.
    Gerard>
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    Default Re: Aerodynamic fairings for motorcycles

    I am interested in this project too. Craig Vetter still believes in this fairing and pairing it with a Honda helix scooter.At $1300 and change it is another way to avoid making your own fiberglass molds.

    But knowing what you can do... I think a shaped foam core could emulate a similar design. a light fiberglass and carbon fiber blend could provide an amazing fairing at less than 1/3 the price. Placed on a Chinese 125 scooter or even a postie, One might estimate or even expect a 125 mpg country road ride given the tire choice and gearing. I hope you make one which we can aspire!

    On a side note, my 2-stroke 49cc board track racer-bicycle gets 138 miles to the gallon at an average speed of 21.5 mph. top speed is 44 mph - too scary and wild. But still amazing gas saver non the less with a build cost of 225 for everything. Downside is that it should only be run for 20 minutes or 4 miles before it and I need a break.
    Last edited by Ted Hoppe; 07-26-2011 at 12:38 PM.
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    Default Re: Aerodynamic fairings for motorcycles

    http://craigvetter.com/pages/470MPG/...20Fairing.html

    From Craig Vetter website:
    You are looking at a year of my work as of August, 2010 and it still isn't finished. The goal is ultimate fuel economy and rider comfort. I am trying for 100 mpg at 70 mph, into a 30 mph headwind with 4 bags of groceries. Is it possible? I don't know yet. So far, I can get 70 mpg in these admittedly very tough conditions. Oh yes... in a garage full of vehicles, I want this to be so convenient, so easy to ride, so much fun and so comfortable that it is my first choice.
    This would surely make it the Last Vetter Fairing. What else would there be to do?

    It is also the first Freedom Machine. Because with it, I hope to help establish a new class of licensed of vehicles in America that rewards responsible citizens with freedoms others don't have. . . . . . . . . . .. . . . . .

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    Default Re: Aerodynamic fairings for motorcycles

    A diesel powered motorcycle that would be capable of 200 mpg (Imperial ) or US 166 mpg.A cruising speed of around 55mph .Some weather protection .



    Thanks Ted , encouraging !
    The 500 cc petrol Enfield will get 100 mpg Imperial at around 40 mph without a fairing ,a diesel engined one with Dreamliner or an improved version ...should that achieve at least 150 mpg US .

    Can you suggest any improvements to the Dreamliner?

    BTW ,I am a bit suspicious that the Vetner fairings would be very subject to cross winds .
    '' You ain't gonna learn what you don't want to know. ''
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    Default Re: Aerodynamic fairings for motorcycles

    I think a Royal Enfield Tourus might also make an excellent diesel high mpg bike - the factory reported a nearly 200 mpg. With a proper Airtech reproduction of a Gilera 125 dustbin fairing and streamlined rear you could approach an astronomical mpg. the downside might be that it is quite noisy, smelly and rough. I think good ventilation and proper cooling are your biggest challenges but nothing you couldn't overcome.

    The dustbin racers from the 50s changed the face of motorcycle racing. Lots of past and current experts disagree about the crosswind dangers too. The simple fact that these fairing small italian and german 250s spanked the big factories proving gross horsepower wasn't everything. The big organized factory responses to these small dustbin bike upstarts at places like the isle of man and at the Grand Prixs were to ban them.

    A couple of years ago a few motorcycle artists/welders made an alumium dustbin bio-diesel bike made by folks called the Crucible which was ridden about San Francisco and even clocked at speeds of 120 on highway 280 (I know they even made a run on the Bonnaville Salt Flats in 2008). What I find as interesting on this subject is the fact that the current crop high end electric motorized bicycles have these dustbin fairings to improve efficiency and speed over distance.

    Last edited by Ted Hoppe; 07-26-2011 at 07:01 PM.

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    Default Re: Aerodynamic fairings for motorcycles

    I'm having a hard time meshing the stated goal here with what's already been or is being done. In cars, the original Insight could squeeze something like 70 miles out of a gallon, and the Loremo is getting around 120 mpg for the LS model. And that's a weathertight vehicle that can fit four. Stats here. Why couldn't a streamlined 2-wheel vehicle with a small diesel reach 200 mpg?

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    Default Re: Aerodynamic fairings for motorcycles

    Quote Originally Posted by Gerarddm View Post
    There was the similar concept English Quantum, which never went anywhere.

    At a lesser scale, Charlie Perethian at Parabellum has been producing wind-cheating windshields and such for motorcycles for decades.
    Do you mean a Quasar?

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    Default Re: Aerodynamic fairings for motorcycles

    Quote Originally Posted by Woxbox View Post
    I'm having a hard time meshing the stated goal here with what's already been or is being done. In cars, the original Insight could squeeze something like 70 miles out of a gallon, and the Loremo is getting around 120 mpg for the LS model. And that's a weathertight vehicle that can fit four. Stats here. Why couldn't a streamlined 2-wheel vehicle with a small diesel reach 200 mpg?
    It's extremely difficult to make a fairing that is in any way comparable with car aerodynamics .It's that great big lump up on to that wants to get on and off .The turbulence is quite horrendous .

    The Dreamliner gives a 26% increase over unfaired mpg and the diesel gives around a 70% decrease in fuel burned .... it's a good start and something I can build myself. I can only agree that the Loremo is wonderful bit of design but outside my budget I'm afraid.

    Can anyone suggest improvements to the Dreamliner fairing that would reduce drag and turbulence ?
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    Default Re: Aerodynamic fairings for motorcycles

    Quote Originally Posted by Ted Hoppe View Post
    I think a Royal Enfield Tourus might also make an excellent diesel high mpg bike - the factory reported a nearly 200 mpg. With a proper Airtech reproduction of a Gilera 125 dustbin fairing and streamlined rear you could approach an astronomical mpg. the downside might be that it is quite noisy, smelly and rough. I think good ventilation and proper cooling are your biggest challenges but nothing you couldn't overcome.

    The dustbin racers from the 50s changed the face of motorcycle racing. Lots of past and current experts disagree about the crosswind dangers too. The simple fact that these fairing small italian and german 250s spanked the big factories proving gross horsepower wasn't everything. The big organized factory responses to these small dustbin bike upstarts at places like the isle of man and at the Grand Prixs were to ban them.

    A couple of years ago a few motorcycle artists/welders made an alumium dustbin bio-diesel bike made by folks called the Crucible which was ridden about San Francisco and even clocked at speeds of 120 on highway 280 (I know they even made a run on the Bonnaville Salt Flats in 2008). What I find as interesting on this subject is the fact that the current crop high end electric motorized bicycles have these dustbin fairings to improve efficiency and speed over distance.

    I agree Ted but the Taurus isn't available here , what i have in mind is a home built version .Noise ...definitely .That is probably the major negative .I'm hoping a bit of cunning design including multiple layers of lead backed foam sound deadening material plus ducted cooling air will help.

    The major design problem with fairing is the sitting position If the seat could be lowered sufficiently a feet forward position would lower the frontal area significantly ....but here is a frame in the way . The frontal area is directly proportional to drag and therefore to power required and fuel used .
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    Default Re: Aerodynamic fairings for motorcycles

    Oops, yes, Quasar, not Quantum.

    In fact, there's a story in today's online NYTimes about Craig Vetter's challenge prize. That yellow fairing contraption of his? Made from recycled binder covers, fer crissakes. Ingenious bugger, ain't he?
    Gerard>
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    Default Re: Aerodynamic fairings for motorcycles

    Quote Originally Posted by Gerarddm View Post
    Oops, yes, Quasar, not Quantum.

    In fact, there's a story in today's online NYTimes about Craig Vetter's challenge prize. That yellow fairing contraption of his? Made from recycled binder covers, fer crissakes. Ingenious bugger, ain't he?
    It's certainly rough!! There have been some very good entries in his prize competition though .I really wonder how crosswinds would effect the yellow one !
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    Default Re: Aerodynamic fairings for motorcycles

    Great thread Peter... I have been thinking along the same lines
    in making a high miler, But around a recumbent bicycle.
    That would solve the problem of too much frontal wind resistance.
    A 65cc Chinese motor supplying power.
    These motors will push a standard bike to 45mph at about
    150 mpg. I figure that with a recumbent bike w/ full body kit,
    I could re-gear for a higher mph and break 250mpg
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    Default Re: Aerodynamic fairings for motorcycles

    Quote Originally Posted by PeterSibley View Post
    .....The frontal area is directly proportional to drag and therefore to power required and fuel used .
    You don't have to go FF....
    You could kneel
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