Chapter 48: Streamlining a Ninja 250: Part 5
After two years of watching how the elements affect my streamlined Helix bodywork, I can see that the lower portion of the body ought to be more durable and have more substance. Randy Schlitter of RanSport - a designer and manufacturer of homebuilt airplanes - suggested I try .020" aluminum. I ordered a roll from Aircraft Spruce.

Making the lower Streamliner Body skin
Having lots of Milk Carton Paper around makes it easy to mock up the bottom shape.

We have to guess at where the skin is supposed to be since the entire bottom has been cut away so the body will slip onto the bike.

Little by little, we glue scraps of the paper in place with the hot melt gun, generating the full shape of the bottom.

We can see that the Ninja 250 exhaust pipes want to protrude from the skin. Better to discover this now in paper than to wait till we have cut aluminum.

Confirming the Streamliner Body will still come off OK.

We have trimmed away only what is necessary to remove the Streamliner Body skin. Three bolts, unplug the wiring and it is off. Imagine how easy this makes maintenance!

A small bulkhead finishes the new strucure

This holds the new skin and keeps the rear from filling up wth stuff thrown up from the rear wheel. It is like a big fender.

Think about this: There will no dirty water spray to be sucked up onto your back.

The next step is to make a symmetrical shape in milk carton paper.

We need to test for tire clearance and to be sure the body still goes on and off. The Ninja's mufflers exit inside the surface of the streamlining. We must figure how to get the exhaust outside.

"Streamlining is easy to say but hard to do. My job is to make streamlining easy"

Craig Vetter

The template for the bottom streamlining is ready to be made of aluminum

This is the first time I have unrolled the .020" aluminum. This is nice stuff. It has clear plastic on both sides to protect it. I cut it out roughly with snips and finished it on the band saw. It fit the Streamliner body perfectly.

Pop-Riviting the skin to the body

When that thin aluminum gets curved, it gets strong. I think it could be thinner and still do the job.

Making exhaust diverters

I have learned from experience with my KLR 650 that the the exhaust gasses get really hot. Alan makes the diverters from the .020" aluminum and Pop-Rivits them in place.

Diverters in place

Routing gasses on the Ninja is a lot easier than the Helix which has a muffler that bounces up and down.

Streamlining with Milk Carton Paper

We pre-drilled 1/4" holes about 4" apart in the body framework. Then we wrapped the body with the Milk Carton Paper and lit up the inside with a lamp to see the holes. It was simple matter to push a sharp awl thru the paper at the hole and then press the Banana Tacks into the holes.

Special Vetter Banana Tacks make streamlining easy
The Vetter Streamlined Body Kit: One of the three components that makes up the complete Vetter Streamliner Package.

We eagerly await Alan's report after his first ride. Still to be assembled: The Nose and the Tail.


How the Ninja frame might be lowered:
PhotoShop Montage of Alan Smith and his lowered frame 250 Ninja
Thru the magic of PhotoShop, I assembled the major components for the Dream Ninja Vetter Challenger. I sent these to the folks at Kosman and included them in a few E mails. Below you can see the rough placement more clearly:

With some layers deleted, we can see what is going on a little better. The rear wheel is moved back 6-8". The rider sits about 6" lower. Foot controls are mounted forward. We must strike up the best compromise for the rider's position. He must still be able to grab the handlebars comfortably. They must be of the correct shape and position to operate intuitively. The short Ninja makes this problem more managable and it appears that Alan will have no trouble riding comfortably in the position above.

It looks like Kosman will not be able to help with this project.

Of course, there are other ways to sit far back and hold the handlebars comfortably:

Other solutions to lowering the rider:

Andy Tribble's masterpieces. It takes a lot of work to do it right.
Andy welded in another steering shaft and bearing, closer to the rider, tying to the original fork head with a ball joint ended strut. The above pic is a little difficult to read because it is two different bikes, parked side by side. Look at those modifications!

Andy says: "You can see that there is a black machine and a grey machine. They are
both MZs, spine-framed German lightweights that are almost non-existent in the US but were common enough here."

Set back steering

"Both machines have had their swinging arms extended by having an extra section welded in, thus pushing the rear wheel further back, but the top mount for the rear springs is also further back so that the spring rate is (we hope) about the same. The black machine has a tubular frame, the grey one has a later box section frame. The black one has some bodywork, I attach a thumbnail of what it looks like complete. Both have had extra tubes welded in under the seat area for more strength, the black one is fine but the grey one in my opinion is not strong enough so more will need to be done."

"The shot of the grey one from above shows a common solution to the problem of sitting a long way back from the handlebars. All the Quasars have two steering heads like this."

So, Andy... what is it like to ride with this kind of steering geometry?

Does anyone else have riding experience with a remote steering arrangement?

The covered wheels are proven to be very effective in rotating drag reduction.
Andy Tribble and me, England, 2008

While searching for pics, I discovered this pic of Andy climbing into the "Tudor Thomas "Slug." (No, I am not making this up):

"Tudor Thomas Slug": I don't think it will win any Fuel Economy Challenges

Master Index to the Last Vetter Fairing Story

Posted Oct 10, 2011

Updated Oct 17, 2011

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