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

[theycallmeebryan]

I tried to think if a good name for this project. All i could come up with is a cross between "slippery" and "sipster" (from Top Gear America's project).

I have mentioned previously in my Ninja 250 general thread about my ambitions to design and build a streamlined fairing for my motorcycle. I'm a 22yr old college graduate with a BS in PreMed Biology, and will soon be starting a new job with the degree that may require lots of driving. My motorcycle is my primary vehicle, so the main goal with this project is not only to improve the fuel efficiency of my motorcycle, but to also improve the comfort of the ride as well as extend the conditions for which i can ride (Temperature, weather, etc). The fairing will be made entirely out of steel or aluminum bar stock for the framing and a thin layer of fiberglass for the shell.

There are a few design considerations that i would like to follow:

1. The design will accommodate an upright riding style. This means i will be sitting comfortably with my back straight and arms relaxed.

2. The fairing will be at least as easy as the stock fairings to remove from the bike.

3. The fairing will at least consist of a front and rear fairing, and mounting and unmounting the bike will be easy. If possible, i would like to enclose the sides for better airflow from front to rear.

4. The front fairing will be as wide as my handlebars and foot pegs (approximately 30"), and as tall as my helmet in an upright position. The front fairing will extend forward past the front wheel and fully enclose it.

5. I'd like to retain the stock headlight, tail light, and blinkers with the fairing. The less parts i have to buy, the better.

6. The rear fairing will cover the passenger seat and extend up to the back up my helmet, possibly even having a back rest built in. The rear fairing will follow a tear dropped shape.

7. I'd like to incorporate storage spaces in the fairing, ideally front and low on the bike, but also behind me. I'd like to be able to carry a bunch of clothes, maybe some groceries, and a laptop.

Goals that I would like to meet:

1. Allow riding in sub freezing temperatures without having to wear 4 layers of clothes under my riding gear, a ski mask under my helmet, and ski gloves instead of riding gloves.

2. Be able to safely store payload on the motorcycle and not have to worry about it falling off the bike (a bungee coming loose)

3. New MPG goal : 125MPG

I plan on starting on the fairing soon. However, i would like to open this thread up for discussion and allow the EM community to provide suggestions and insight on this project. I have read the quests of Craig Vetter and others and understand a bit about full fairings on motorcycles.

Here are some designs i have whipped up real quick to get the discussion started.

First, a mock up with clay of a possible design:


Heres a quick side view of a fairing that fits an upright riding position:


Heres a top down view of what the shape of the sides will probably look like:
First closed:

Second, opened


Here is a current picture of my bike with extended windshield:


And here is an older picture with me sitting on the bike:


It could look something like the Prometheus EV Ninja:

[Tygen1]

Craig Vetter Fuel Economy better mileage

Here some interesting reading for you...

Oh ya, Go Go Go!

Edit: Just saw that you've read Mr. Vetters stuff...

[Christ]

That clay model you made, almost perfectly resembles the "Rifle" body that Vetter sells.

My suggestion to aide in your 125MPG goal would be replacing your lights with LED versions. Of course, if you use the stock lights that hang out in the wind, it will completely ruin your aero... :P

I don't think a funtional backrest would do you any good, really. Seems like you're still slightly leaning forward in that pic, so unless the backrest was further forward than it needed to be, you'd never contact it anyway. Your back is slightly arched toward the thoracic vertebra, so the lumbar area could benefit, slightly.

[MetroMPG]

Excellent! This will be interesting.

Suggestions... Well, there's likely nothing you don't already know if you've read through Vetter's site.

But I want to emphasize using CAD (cardboard aided design) because it's quick, practically free (tape costs a bit), and relatively fast way to come up with fairings you can test before building "good versions".

Highly recommend TUFT TESTING your work before committing to a design. I've seen more than a couple of members here put hours of work into aero projects without tuft testing, and then end up disappointed when the mod doesn't appear to work well.

[cvetter]

I hear a lot about the great mileage the KZ250 gets. Personally, I think there is something very special about a 125s bore and stroke. The KZ is just 2 of them which could help explain why it is so good. You have probably seen that I am very specific about conditions. "Vetter Conditions" are 70 mph, into a 30 mph headwind, with a good load, (I like 4 bags of groceries) sitting up and comfortable. It needs to be our first choice in a garage full of vehicles.
Will you be operating in these conditions?

It is really important to document the mileage are you getting now, before you make changes, in these conditions. Can you do that and post the results? Can others with Ninjas document their fuel consumption in the "Vetter Conditions"? This will go a long way in helping us understand the results of the streamlining we come up with.
Craig Vetter

[Jethro]

It's neat looking. I'd be worried about the effect of high speed winds getting between the front 'faring' and the 'fender' (Not real sure what you'd call them on this)

My 08 FZ1 seems to be rather particular, when I rode w/o the faring once WOW, it was far less stable.

[brucey]

I also second tuft testing for the same reason MetroMPG said. (;

I would say another way of testing is also top speed runs, but unless you have your own track thats illegal. And always dangerous.

My 250 topped out at 110 mph or so but that was on a good day.

Do you plan to carry passengers?

[theycallmeebryan]

Originally Posted by cvetter

I hear a lot about the great mileage the KZ250 gets. Personally, I think there is something very special about a 125s bore and stroke. The KZ is just 2 of them which could help explain why it is so good. You have probably seen that I am very specific about conditions. "Vetter Conditions" are 70 mph, into a 30 mph headwind, with a good load, (I like 4 bags of groceries) sitting up and comfortable. It needs to be our first choice in a garage full of vehicles.
Will you be operating in these conditions?

It is really important to document the mileage are you getting now, before you make changes, in these conditions. Can you do that and post the results? Can others with Ninjas document their fuel consumption in the "Vetter Conditions"? This will go a long way in helping us understand the results of the streamlining we come up with.
Craig Vetter

Craig,

I appreciate the comments from you. You can view my ongoing fuel economy log in my main thread here: http://ecomodder.com/forum/showthrea...50-a-8686.html

[Christ]

Craig's a genie... say his name enough times, and he shows up to speak.

So, theycallmebryan -

Wire coat hangers can be wrapped togehter to make a nice sub-structure for a skin to be applied to. Or, you could get fence wire from a farm store, if there's one near you. That stuff is fairly stiff, as well.

[MetroMPG]

Let's not forget that coastdown testing (A-B-A) is another quick, easy and relatively controlled way to compare fairings which are easily installed/removed.

It won't directly give you MPG figures, but it will give you an answer about whether "A" or "B" is better.