Just joined the aerodynamic crowd.

[Alex]

Originally Posted by Bubba

Google "Kamm tail".

There is no reason to have the tail that long and taper to zero. It you have the proportions right, air will flow off a Kamm tail in exactly the same shape, but be much shorter.

Makes sense, but one of the requirements of the fuel mileage contests these bikes enter is to be able to carry a certain amount of luggage (4 grocery bags I believe). That space in the tail can't be made too small, even if it isn't making much (any?) difference aerodynamically.

[JeffM]

Have some of the "skin" on the frame and have rigged up the tail/brake lights, license plate lights and turn signals. I am having a bit of trouble with the signals - the suddenly started acting like emergency lights. I started a separate thread.

https://www.ninjette.org/forums/show...031#post890031

Jeff

[JeffM]

Originally Posted by JasonJ

Jeff, what kind of soft saddlebags do you have and are they still available for sale anywhere? Those are exactly what I am looking at for my ninja250 short distance sport-tourer project!

Also, fantastic job this whole way through! I am very impressed at your dedication and fabrication on this aero project.

Thanks!

They are discontinued. They used to be the in-house brand for Cycle Gear and were called "Cargo" brand.

They have been pretty good bags.

You might want to go to Cycle Gear online and check out their Sedici brand bags. They look pretty good in person.

Cortech makes pretty good bags too.

Jeff

[JeffM]

Originally Posted by Motofool

Any update?

Removing the flutes on the inside of a sheet worked great! Very labor intensive


Now I just need to solve my turn signal problem (see post #82), finish up the build and ride.

Edit*** with assistance from @verboten1 I was able to get past the problem. Thanks.

Jeff

[JeffM]

Getting there. The top skins are on temporarily for fit hence the wrinkles. Need to add the sides, change the gearing (15/39 waiting for a master link), tidy up some details then go for a ride

I will worry about making it pretty later.

[N-m]

Are you going to finish the aerodynamics first and evaluate the results and then change the gearing so you have fewer parameters to consider when reviewing performance increases?

Nice job so far.

[JeffM]

Originally Posted by N-m

Are you going to finish the aerodynamics first and evaluate the results and then change the gearing so you have fewer parameters to consider when reviewing performance increases?

Nice job so far.

Thanks.

Probably,and that is a logical way to evaluate the changes. I average 50mpg on the stock bike and it will be interesting to see how just the aerodynamics change my mpg without a gearing change.

With gearing and aero changes I am thinking I should obtain about 80-90 mpg with fairly normal riding. Hypermiling, of course, will yield greater results.

[JeffM]

Alan Smith stopped by this morning, with riding buddy Dave, to see how my build was coming along. He was on his way to the Vetter Fuel Challenge at the AMA Vintage Days, Mansfield,Ohio .

Our bikes:


Alan, in the red shirt, with his streamliner and Dave with his Vstrom 650.

[Motofool]

Originally Posted by JeffM

Alan Smith stopped by this morning to see how my build was coming along. He was on his way to the Vetter Fuel Challenge at the AMA Vintage Days, Mansfield,Ohio .

How does he cool his engine?

[N-m]

Originally Posted by Motofool

How does he cool his engine?

If that's a Ninja the liquid cooling system is going to have to work overtime unless there are vents we can't see in the picture.

Tell us more about this event in OH.

[JeffM]

Originally Posted by Motofool

How does he cool his engine?

The duct under the headlight. I'll let Alan answer your question - http://www.craigvetter.com/pages/201...nja-p69b.html:

Alan reports from the road: Riding through Southern California, Arizona, and New Mexico a few days ago my streamlined Ninja 250 has been running hot most of the time. Not overheating but running hotter than usual. Normally it runs fine everywhere else in North America. One possible reason for running hotter is that the strong cross winds might not be flowing properly onto the intake of the aerodynamic nose to my cooling system. The other modification I might need to do is open the intake in the nose. For anyone building a streamlined motorcycle, over cooling is easier to deal with on the road than over heating.

Parking is still a problem in high winds. In some areas I was told that even full size $30,000 Harleys blow over in the parking lot. So for all you current and future streamliner guys (and gals) think about how to park it in the wind. Terry Hershner knows this problem very well.

Now the good news, this trip is showing that my streamlined Ninja 250 can keep up with the full size motorcycles (over 1,000 cc). My riding buddy has no complaints about me keeping up. We have been riding a lot of 80 MPH cruise speeds. My top speed has been over 90 MPH passing semi-trucks. I must admit that I am pushing my streamlined Ninja 250 harder than I usually do.

With my taller gearing at 80 MPH my Ninja 250 engine is running about 6,200 RPM. This might seem high but the engine red line is 13,000 RPM so I'm only running less than half my RPM range. Currently my Ninja engine has over 56,000 miles on it.

On this trip the fuel economy is basically double the full size motorcycles at the higher speeds, 47 vs 99 Miles-Per-Gallon. Of course if I slowed down my fuel economy would be much better.

Alan Smith.

[JeffM]

Originally Posted by N-m

Tell us more about this event in OH.

http://www.craigvetter.com/pages/201...ouncement.html

[Motofool]

Originally Posted by JeffM

The duct under the headlight. I'll let Alan answer your question..........

That is very common problem in engine's cowls of airplanes; hence, the invention of the NACA duct:

http://en.wikipedia.org/wiki/NACA_duct

http://www.formula1-dictionary.net/naca_duct.html

[JeffM]

Alan sent me an email this morning:

The results are unofficial at the moment but using the odometer on my motorcycle I rode 154.2 miles and consumed 0.848 gallons of gas. That works out to 181.83 Miles-Per-Gallon vs Fred’s diesel motorcycle at 178.26 MPG! I beat the diesel guy, and good friend Fred, by 0.017 gallons of fuel.

Congratulations Alan

[spooph]

This is so cool!
@JeffM - why the low mileage without the aero? I'm currently getting 70mpg on my 2008...

[JeffM]

Originally Posted by spooph

This is so cool!
@JeffM - why the low mileage without the aero? I'm currently getting 70mpg on my 2008...

I usually get around 50mph cuz I ride like I stole it.

I am certain that if I short shift and ride more highway miles my mileage would improve a bit. Right now all I do is commute on surface streets and canyon ride.

Jeff

[spooph]

Originally Posted by JeffM

I usually get around 50mph cuz I ride like I stole it.

I am certain that if I short shift and ride more highway miles my mileage would improve a bit. Right now all I do is commute on surface streets and canyon ride.

Jeff

Jeff,

this really bugs me... Do you have access to an A/F guage like the innovate? Is your jetting accurate? If I remember correctly you are at 5,000 feet, right? I had to jet down quite a bit to adjust my bike's stock settings and am getting great gas mileage because of it...

[JeffM]

Nope, have not fooled around with the jets. My bike is a stock California bike.

[spooph]

@JeffM - if you want, you can borrow my innovate and get that puppy dialed in... Also, definitely remove that emissions crap... extra weight and contaminates the mixture... We could meet in Grand Junction, or Moab? Or I could mail it....