Chapter 44: Streamlining a Ninja 250
Zak Vetter raises the front wheel as Alan slips the Vetter Kit nose structure into place

The Kawasaki 250 Ninja has proven to be a serious candidate to be a Champion Fuel Challenger. Will the new Vetter Streamliner Kit fit the little Ninja?

Alan Smith wanted to find out.

Sure looks big on that little bike... until you remember that Vetter streamlining is made for the person, too, not the just machine.
You are looking at the basic structure of the new Vetter Streamlining Kit. But, will the body parts fit? How will they look?

Using PhotoShop:

We superimpose the main streamliner body over the rear. These parts are from my streamlined Helix, as yet unfinished. The parts are rough but give us an idea of fit.

Now we add the streamlined nose from the Helix

And the windshield. Gonna have to be trimmed for Alan - or the handlebars will need to be raised. Right now, the bars are almost within the 28" width of the body.

By adding the rear tail, streamlining is complete. The Ninja frame is 26" high, forcing the rider to sit high. For reference... the frame on my Helix is 23" high.

I think Alan will want to sit feet forward too. This will mean forward controls and a floorboard to help streamline the bottom. In the above image, I have added Alan in "feet forward" position.

All this just points to somehow "scooterizing" the Ninja 250. I am working on a way to do this. It is such a short machine to start with, it just might work. Anybody want a Ninja scooter?

Steps in streamlining Alan's Ninja

Below are pics of Alan and me making the streamlined bodywork for his Ninja. We began with the Vetter Streamliner Kit .100" aluminum pieces which were water jet cut from a CAD file. If we assemble them accurately, we will have a perfect, wrinkle free surface.

The two main body bulkheads. The key to accurate and quick assembly is knowing the exact angles of the connector tabs. Each one is different. Your kit supplies those angles for you.
Connect the pieces with little angles by drilling four holes and Pop riviting the parts together.
Pop riviting the parts together. I am using an air riviter which,by the way, makes a great sound. A hand operated riviter works just fine.
Shaping the rings. This takes a little time. But since the shapes are perfect, you will know when the arc is right because is the only shape that fits perfectly.

Late at night, we did a trial wrap of milk carton paper to check the fit. It seemed perfect.

Having Alan to help made it even more fun
The next day, both Alan and I had come to the same conclusion: The Ninja seat was too high and had to go. This would allow us to mount the rear streamlining directly to the frame. Three points in space are required to locate something. We would build a structure that would be attached by three bolts only. It would be designed to come off - entirely - in seconds. The front streamlining will be mounted the same way. I am a lazy mechanic and have no patience for a design that is more trouble than it is worth.

Let me tell you a story about a wonderful set of fairings that was disgarded because it was

"More trouble than it was worth"

In 1929, Boeing made this mighty airliner, the Model 80. It came from the factory with wonderful streamlining - top photo. Even though it helped to save fuel, mechanics hated the fairings beause they could not be easily removed for routine maintenance. Within a couple of months, the wonderful streamlining was gone.

We don't want to make this mistake today.

We need the streamlining to be left on where it can help us to live better on less fuel..

Our streamlining must not be more trouble than it is worth.

Back to streamlining Alan's Ninja:

It was time to figure out how to mount the rear body to the Ninja and be "not more trouble than it was worth". We began with the frame where the seat used to be:

I start out with a paper template. Well, I use milk carton material because it is so plentiful around my shop.
After hours of fussing, we arrived at this shape. The circles are where Alan's Ischia bones carry his sitting weight. I like to have a lot of area under the ischea in seats because it spreads the load and keeps your butt from hurting.

The rear body structure is taking form. Alan is pleased. I am pleased, too.

This is a grand experiment. We will be adding much more side area to Alan's bike. Will it affect handling? Will it consume less fuel? Will it carry the groceries?

Chapt. 45: Ninja Streamlining, Part 2

Master Index to the Last Vetter Fairing Story

Posted Aug. 26, 2011

Updated Aug 31, 2011