Project Slipster: Streamlining the Kawasaki Ninja 250 (WIP Thread)

[Rokeby]

For some informed insight on the problems experienced with "fully enclosed"
motorcycles, Google "dustbin fairing."

An interesting fully enclosed electric 'cycle:

Schultz Engineering - Building an Electric Motorcycle With Dustbin Fairing

[3-Wheeler]

Originally Posted by theycallmeebryan

One of my goals with this project is to increase protection from the outside elements. Also, in my main thread i had talked about back pain i was getting while sitting in a crouched position for extended trips.

Hi Brian,

I do remember you mentioning your back pain in another post. I guess I have been lucky in that regard as my back feels good after commuting all the way to work hunched over to increase the mileage (50 minutes).

Anyway how about something that could hopefully help your back out?



Actually there is allot going on with this design...

On the plus side you get a better seating position, good back support, lower center of gravity and lower CdA.

The minus side you would have to permanently modify your bike by altering the frame and such. You may not be up for such a radical modification.

My bike has enough miles on it, that I would not hesitate to try something like the Alligator, but this may not be for everyone.

I have often thought of adding a third wheel so I don't have to put my feet down at a stop.

Imagine how wild you could go with the aerodynamics with three wheels on the road? You could almost be fully enclosed, and if you have enough weight on the outside wheel, the wind will not flip you, but simply cause some side slippage of the tires. Just make sure you center of pressure is behind the center of gravity and the steering will self align.

If I were doing a motorcycle with two wheels in line with a side hack, this would be my starting point. Keep the seat as low as you can, and still see over the triple clamps for good forward visibility.

By the way, the side hack would be nothing more than a platform that the outside wheel attaches to. The whole framework could be aero in shape, and very sleek. Maybe point the airfoil towards the ground slightly for a small amount of downforce on windy days.

Craig Vetter should try something like this. He can still get his "four bags of groceries" in the tail section behind the rear tire.

Jim.

[3-Wheeler]

Hi,

Not to beat a dead horse here, but Matt Guzetta rode a Suzuki fully streamlined bike in the 1980's Craig Vetter High Mileage Contest also.

He went on to say that the two wheeled machine could be a real challenge in windy conditions, and just about lost it on several occasions.

Again, this an extreme, hunched over the bars, posture, and not helpful to Bryan's sore back.

The bike had ten gallons of fuel mounted right over and around the front tire for stability.

Ride the Machine.: Matt Guzzetta's High mileage Suzuki.



For full wind coverage on a motorcycle in the ultimate Cd reduction package, and making it practical, one is really looking at three wheels for stability and safety.

It seems that the only way to get two wheels to work in a full blown package, is to make a Bonneville Salt Flats machine and ride it on calm air days.

Jim.

[Christ]

Jim -

I love that recumbent seating position. If I were somewhat more (insert word), I'd cut the frame on my Honda and do something similar. There's a large area under the seat that just doesn't really need to be there, ya know?

[Christ]

Originally Posted by theycallmeebryan

Are you talking about something like this?



Ran it through flowillustrator:
http://www.youtube.com/v/xZT511YgBnQ&hl=en_US&fs=1&

Either move the front section forward by about 10 px, or bring the outer edges of the rear section in by about 4-5px each. You'll get a "quieter" ride, without wind buffeting.

You see how the air is hitting the rear fairing and rolling inward? That middle section is a low pressure zone (obviously), and the air is going to try to fill it in as it separates from the front fairing, so you taper in the leading edge of the rear and make the edges not as rounded. This will help keep the airflow trained in one direction.

[thatguitarguy]

Hmmm... Getting closer

[theycallmeebryan]

Sorry guys, havent had a chance to work on the mockup in the past day or two..... i've been enjoying the over 2 feet of snow we got!

Im off to go skiing today.

[JasonG]

While the "Alligator" seems cool, in many states its illegal.
To keep people from riding barely visible streamliners on the street, many states have a 24" minimum seat height.
Now if its legal where you live. ......

[Cd]

What do you guys think of testing using a large toy motorcycle, a strain gauge and a powerful wind machine ?

You could even give it to your kids when you're done

[janvos39]

I am looking today into the thread about fairing for Ninja. Maybe it can be of help when I put my experience with full fairing in writing. I have now approx. 10000 km with this Suzuki burgman with full fairing. Recently I have redone the back part for the fourth time. I changed the backrest and made it possible to hinge forward so that I can put my helmet and office stuff in there easily. My fairing is using a partly closed front wheel. I do not have problems with that in windy conditions . With full side wind there is always still the opening between fender and fairing which reduces the side force.
I have two doors on a hinge. They are "locked" with magnets. In some traffic situations where I have to put my leg quickly to the ground I open them with leg of knee. The wind closes the door again. I put my elbows outside the fairing when there is a lot of side wind. This gives more drag but gives bettter handling of the bike. It is anyhow good to be able to put elbows outside the fairing for low speed manoevering. I plan still a modification on the doors so that I can remove them quickly and put in the back storage space. This incase wind is really bad. (have not had that yet).
In general having a limited side area helps in windy conditions. So seating height is important. I have a seat at 62 cm from the floor. Highest point of the fairing is 137 cm. But my helmet is extending above the fairing.
Also we have snow at the moment so I can not drive the scooter at the moment. Have to wait to see the results of engine capacity reduction (297 cc instead of 385 cc.)