Introduction & Cross wind solutions to motorcycle Streamliners?

[Teri_TX]

Hi Ironside,

Thank you for the link. I just finished reading Creasey's article on Aerodynamics. I'm still trying to understand his reasoning for his "flow separation". As I said in my earlier edited (you may not have noticed) reply, The Creasey's rope is a turbulator which as I pointed out ALWAYS creates turbulence and potentially drag.

A better solution would be one that causes lift generation to be ruined as needed. Hence my "enthusiasm" for the stall strip concept. I'm not permanently joined at the hip with stall strips but I think they provide a fruitful development path. By this I mean that perhaps some careful shallow steps on the sides could destroy the lift in a controlled manner without excessive extra drag.



See my attachment. Note the slope at the step which may (I hope) keep airflow attachment in a calm or direct head on air flow with very minimal extra drag but in a cross wind situation, cause a flow separation and thus lift destroying effect. That's my theory and I'm sticking with it (for now)

I noticed the swoopy lines on the side of Allert's streamliner. I wonder if it was just for appearance reasons or if Allert was attempting to do as I suggest in my sketch.

-- Teri

Originally Posted by Ironside

My mistake Teri, technical aspects of ff design at Technical aspects of FFs | FF Web. There's a menu that will take you to individual aspects you might be interested in.

[Teri_TX]

Hi Visionary,

Thank you for the welcome to the club.

Sadly, I am a long way from trying out my ideas on a real vehicle. I have yet to get a motorcycle and all the other requirements such as certification and license, insurance, body gear, etc. For now I will have to rely on theory and other means such as your generous offer to try out some of my ideas.

I do agree that there is a very highly subjective "rating" system on cross wind behavior. Allert said his streamliner was good in side winds but his business partner, Theo22, said it was very sensitive and that Allert was in agreement. Theo may just be a very persuasive person and Allert changed his mind. Only they can answer that question. I intend to directly ask Allert about this in a private email.

In my opening salvo (message) I was wondering about scale model wind tunnel tests for obtaining "relative" information on various models and changes. Relative in that I was thinking of data for model to model changes, not to extrapolate to the final real thing. That would provide guidence in making a real body.

I think that the mainstream world and manufacturers aren't ready for streamlined motorcycles because of their "wierdness" and lack of macho men promoting them. Having a very cross wind stable design would of course be required. If the present day equivalents (assuming there are such persons) of Mike Hailwood or John Surtees were to endorse a streamliner, then maybe the big 4 Japanese motorcycle manufacturers would be making them. The FIM is of course a major problem. A chicken or egg first question. The Monotracer is hardly mainstream considering it's cost. If I had that much money to spend on a vehicle, I'd get a VERY nice automobile. I suppose if we had supermodels and macho celebrities cruising Rodeo Drive in Hollywood in a streamliner or the equivalent location in London, we might gain acceptance. For now, we are a distinct minority.

-- Teri

Originally Posted by visionary

Welcome to the club

Hi Teri, welcome to a very small club – people actively trying to understand the aerodynamics of full bodied motorcycles. My own research has shown there to be very little genuine high-quality study in this area and your last comment - “ I wish I had a streamliner to test the theory out on” may prove to be the only way to really know.

I doubt that there is any company or academic institution worldwide currently undertaking serious research on the fundamentals of motorcycle stability through aerodynamics. This is primarily because there are no true full-body motorcycles currently in production other than the monotracer.
Think of all the superscooters and cruisers, which sport significant portions of bodywork and the manufacturers of those products, you would think aero research would be a well-trodden path.
The reasons that it is not are many and varied, but put simply; those people most interested in the subject are blessed with the least resources. Conversely, companies blessed with adequate resources, like the big-four Japanese manufacturers seem oblivious to the opportunities for enclosed motorcycles.


I have evaluated the options (for research), just as you have, and my thoughts are: that the time and expense of building a small scale wind tunnel would not be justified as the accuracy of results are unlikely to provide clear answers. So realistically it means testing at full scale and real-world conditions, ie build one and play.

Of course this testing method is not without hazards, as explained by Roger Dunkley in his aerobike blog.
AeroBike Enclosed Motorcycle

Those brave souls who have tried this method are fewer even than the bike builders. When I recall pictures of Craig Vetter and his tuft testing, I think this represents the most scientific published information. Despite Royce Creasey’s writing and theory I have yet to see similar basic testing methods employed.

It occurs to me while writing this, that tuft testing of a superscooter (with tufts on rider and rear of machine) would advance our knowledge greatly. The ideal test would involve images taken at high degree of lean and during strong sidewinds (maybe simultaneously) as well as the more traditional straight-ahead shots.

Anyway, back to your original question about forms of separation device. I’m a few months away from my own road testing and would be happy to try some of these ideas on your behalf. However, I feel that quantifying the effect of a device is the biggest obstacle, after all the “feel” of a vehicle is a highly subjective subject.

Just like you, I hope a well-informed discussion of this topic results from your opening post.

[theo22]

I think a lot of people have done "research" in some form on streamlined motorcycles, escpecially in the 1950'S untill it got banned for racing because they just went to fast and the racing tracks were not build for that, so too many got killed.
The reason that there aren't many streamlined motorcycles on the market is because it is simply not safe enough ( and I have ridden many streamlined 2wheelers including 1 motorised ) and because the western world is rich enough to ride bigger heavier more fuel consuming vehicles.
Even normal motorcycles are not used by the masses in our western world. Only in poorer economies do you see many light motorcycles riding at a low average speeds, where there is no need for aerodynamic improvements that would seriously reduce practicality.

So building an aerodynamic fuel efficient motorcycle is a very nice hobby, but I don't do it to save the planet nor to provide the world with a solution for transport.
I have no expectation that this will ever be bigger than a hand full of enthousiast building something for themselves. enjoy it, I do

[Grant-53]

Teri_TX, Thanks for your input as I am building fairings for mountain and city bicycles. Even at speed less than 20 mph I am seeing a difference and have had good success dealing with crosswinds. The strip along the top of the tail section is worth testing. It's a bit cold right now but tuft tests on my schedule.

[P-hack]

Hi Terri, glad to see you getting into two wheelers!

I'm gonna (predictably) cut across the grain a bit though. If you are brand new to bikes, I would suggest starting with basic protection from the elements and road rash, full face helmet at a minimum and add gloves/coat/boots/pants. I have gone entire winters with just a basic helmet and winter coat/gloves. I do have a snowmobile shield on my helmet though and it helps keep it from fogging up. I want you to enjoy riding without making it dependent on sorting something like this out. Simple riding gear can solve the all weather problems.

I definitely like to see more done with streamliners, but bikes are a pleasure all the same (and you have a learning curve ahead of you that you need to survive).

+1 cbr250.

[Teri_TX]

Thank you Theo.

I and the others on this forum are fellow enthusiasts. Until the Apocralypse forces us to change, I am doubtful that fully streamlined motorcycles will become mainstream. I don't think I'll be alive then (I hope), i.e. about the Apocralypse .

To get back on subject, Theo, please tell the forum about "Storm Strips" you referred to in our private message. These are indeed the same as what I referred to as "Stall Strips". I Googled translated (storm strips) several blogs (in Dutch) on this term. It seems the Dutch HPV enthusiasts are significantly smarter or advanced than North Americans in cross wind aerodynamics.

--- Teri

Originally Posted by theo22

I think a lot of people have done "research" in some form on streamlined motorcycles, escpecially in the 1950'S untill it got banned for racing because they just went to fast and the racing tracks were not build for that, so too many got killed.
The reason that there aren't many streamlined motorcycles on the market is because it is simply not safe enough ( and I have ridden many streamlined 2wheelers including 1 motorised ) and because the western world is rich enough to ride bigger heavier more fuel consuming vehicles.
Even normal motorcycles are not used by the masses in our western world. Only in poorer economies do you see many light motorcycles riding at a low average speeds, where there is no need for aerodynamic improvements that would seriously reduce practicality.

So building an aerodynamic fuel efficient motorcycle is a very nice hobby, but I don't do it to save the planet nor to provide the world with a solution for transport.
I have no expectation that this will ever be bigger than a hand full of enthousiast building something for themselves. enjoy it, I do

[Teri_TX]

Hi P-Hack,

No need to worry!

When I get a cycle, I'll take all precautions including safety training, etc. I am aware of the hazards of 2 wheeled vehicles as I had a severe bicycle accident about 14 years ago. Although my helmet didn't even get scratched. I did a face plant (shudder!) and apparently had a death grip on the bars as they got bent inconsistent with the impact forces. I got a concussion and several broken bones and bad road rash. I have no intentions of going through the suffering again, at least the road rash.

I hope a streamliner will offer road rash protection (I plan to use Kevlar for the shell). I also plan side rails like Visionary's project. Maybe not as safe as a full race car (?) these days but better than nothing.

I want NO discussion of the Helmet Laws shouting match, so if you want a shouting match on that subject go to the http://ecomodder.com/forum/showthrea...ght=helmet+law thread.

-- Teri

Originally Posted by P-hack

Hi Terri, glad to see you getting into two wheelers!

I'm gonna (predictably) cut across the grain a bit though. If you are brand new to bikes, I would suggest starting with basic protection from the elements and road rash, full face helmet at a minimum and add gloves/coat/boots/pants. I have gone entire winters with just a basic helmet and winter coat/gloves. I do have a snowmobile shield on my helmet though and it helps keep it from fogging up. I want you to enjoy riding without making it dependent on sorting something like this out. Simple riding gear can solve the all weather problems.

I definitely like to see more done with streamliners, but bikes are a pleasure all the same (and you have a learning curve ahead of you that you need to survive).

+1 cbr250.

[Teri_TX]

Hi Grant,

Please see my reply to Theo22 regarding Stall Strips == Storm Strips


You are apparently referring to my reference to Craig Vetter's private email in which he tried a short fence on the tail.

The stall strips (storm strips) are a more elegant solution but slightly more difficult to experiment with unless you have the right material i.e. flexible triangular solid extrusion. Theo22 can tell you where to buy some.

Do you have any links to your work on fairings for mountain and city bicycles?

-- Teri

Originally Posted by Grant-53

Teri_TX, Thanks for your input as I am building fairings for mountain and city bicycles. Even at speed less than 20 mph I am seeing a difference and have had good success dealing with crosswinds. The strip along the top of the tail section is worth testing. It's a bit cold right now but tuft tests on my schedule.

[P-hack]

I wasn't trying to start a helmet safety thread, I use mine for comfort in the winter and rain, and like to feel the wind in my hair in the summer, it's like a convertible

[Frank Lee]

Hair? Oh yeah, I had some once.