Jeff Bales builds a speedbike streamliner - Lunatic Fringe

Matt Weaver's coaching led me to develop an incredible airfoil profile using a free demo copy of DesignFOIL which can be found at www.dreesecode.com. One of the nice things about this design is that it is very easy to sculpt by hand without CNC machinery. I'm able to exactly mimic the computer derived airfoil by extruding the 2D foil shape vertically, then rotating it around to the other side. If I had generated a 3D style design using a high powered computing tool to minimize square footage, I wouldn't have been able to capture the important foil shape as easily, or as well, plus it would have taken me hundreds and hundreds of more hours to get as close to the computer model as possible.

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5/16/03

Initially, the bike was to use a semi-linear drive system which has been abandoned. Because this fairing design captures the computer generated shape more exactly, and more easily, I believe that I'll be able to have greater laminar air flow.

I'm an industrial designer and sculptor and am really glad that I don't have to bring all my skills into play to make this fairing happen! Its simplicity may be the key to success. I'll find out this fall at Battle Mountain!

Most of the components for this bike have been donated or bought on eBay for pennies-on-the-dollar. Total expense so far is $115. 'Not too bad.

In the next pictures, laminate is applied to the form. The construction steps go through adding laminate to the foil shapes and using the mounting screws to adjust the uniformity of the shape.

Cut-outs were added to lighten the structure and allow access to the interior. Putty inside the pattern holds the laminate in place. It's hard to see, but I laid up fiberglass on the inside of the laminate so
that it doesn't flex during the time that I sanded the sides flat. Without the reinforcement, the sides would be uneven due to pressure during sanding. I used two layers of 3 oz chopped mat.
Bondo and spot putty were used to perfect the level surface of the sides. 
I'll be using a telescopic style of outrigger wheels such as those depicted on the Wisil site, but will probably have them on both sides of the bike. The bike is designed to compete in the decimach race only and won't be able to turn well. This will minimize the front wheel opening dramatically. I may not be able to pull up the outriggers until I hit 30mph or so due to limited wheel turn. Missing in the illustration are little details such as wheel fairings, etc. Also, the bike will be a camera bike with no windows, just a terrified, claustrophobic pilot. Air intake will be NACA style at the bottom of the fairing where air will already be turbulent.

As it turns out, the manufacturer of the semi-linear drive system *may*decide to sponsor after all! I'm*supposed* to get word this week. We'll see. They already have a 300mm long crank version developed for racing, but I'm asking for 320mm. Bring on the extra leverage! I'm not holding my breath waiting for these guys to deliver, though. I'm proceeding as if they don't exist. If they come through, I'll use the system. If I get the system, I'll provide a link to their site.


5/20/03
These show tape being used as a separator between the canopy and main body. I need the canopy to match the airfoil below it perfectly at this point so that all further work on it matches as well. You can see that after using putties the base-plate for the canopy matches perfectly! The tape is then removed after separation of the layers. I am now free to work on the canopy knowing that it will match.

The curved part of the canopy is just the airfoil shape rotated from side to side. To spin something this large on a lathe would be expensive and/or dangerous to do. I could have the pieces cut with a laser, but they're just circle halves. How many circles can I cut? A bunch. I've got a lot more to add. The more circles I use, the more accurate the profile will be with minimal detailing. It will only take 3-4 more hours to add another 100 or so ribs, so that's tomorrow night's project. I apply the ribs 1/8" from the edge of the profile. This leaves enough room for the fiberglass skin plus a thin application of putty.

After I'm through super-gluing on the ribs, I'll skin them with 1 1/2 oz chopped fiberglass mat as a connective substrate, then it'll be putty time. I'll be checking the profile with a foil shape cut out of rigid material to ensure that things stay in line with the computer generated foil.

When I designed the foil shape in the computer program I knew that this was the construction method that I would use. I designed a foil shape that is very robust, meaning that minor imperfections don't hinder the foil
performance very much. So far, any imperfections that are inherent in my work are well within the confines of the foil experiments. It required bumps far more severe than anything on the pattern surfaces to throw off the
foil's performance. I observed many foils that were easily thrown off; the one that I'm using is fairly forgiving. That's not to say that I'm intentionally allowing sloppiness in the surface quality, but I'm only a human spreading around putty with a stick and smoothing it out with a $39 in-line sander! If this fairing proves worthy I may build another using all laser cut panels, but that's a different year with more time in it than this one. I think that the simplicity of this design is allowing me to come close to the accuracy of using high tech machinery.
5/22/03
OK, I'm getting really tired of cutting circles now! If you're not a sculptor and are making a canopy like this one, keep cutting lots and lots and lots of circles, or take the time to have them laser cut or machined. Me, I'm ready to move on!


Let's see, a computer generates a grid to revolve spheres and other profiles, so why can't I? 'Time to whip out the fiberglass roving and create a grid in the real world! Twine would have worked the same, but you go with what you know. After wetting the roving with resin, I applied a 1 1/2 oz. layer of chopped strand fiberglass mat to connect everything. After that hardened, I applied a layer of putty over the entire surface. I'll allow this to cure overnight and hit it with 36 grit paper on the inline sander tomorrow evening. I'm still going to verify proper curvature with a rigid copy of the foil after a couple of evenings of sanding and then give it a fine surface finish. 

Ah, it's starting to look pretty zoomy!

5/24/03
I decided to lighten up the canopy a bit since I've been moving it around a lot. The fiberglass substrate will help to keep its shape without the heavy particle board inside. You can see the ribs and the fiberglass roving from the underneath. 'Pretty funky looking!
I'm so glad that I stopped cutting circles. The smoothing of the putty is going really well. I first hit it with a 36 grit disc using a large angle grinder to knock down peaks. Then I hit it pretty hard with 24 grit until some of the grid work started to show a little beneath the somewhat translucent putty. Next I applied a couple of layers of Bondo, leveling between each coat. It turns out that the best tool for perfecting this rounded canopy is not the air powered in-line sander... the best tool is a 3' long wooden 2 x 4 with 24 grit sand-paper wrapped around it. The extra length of the 2 x 4 helps to align the surface and very quickly remove high
spots. Low spots are filled with a very thin layer of putty and hit again. It takes some muscle, but it sure works well! Besides, I can't be training for the race while I'm stuck in the shop building this pattern, so a little work-out is doing me some good.
When I started the process of designing the bike I weighed 230 lbs, now I'm at 218. I'll be at 210 to 200 by race day. Just four months ago I was at 265. It's amazing how one little decision can affect your life. A heavy guy like me with powerful legs actually stands a chance of doing well at Battle Mountain due to the -1.19 degree slope during the run-up to the traps. In fact, it's actually a slight advantage. I figure that the bike with its pilot will weigh somewhere around 280 pounds of mean, not very lean, biking machine.
 

I ordered the camera sighting system from eBay yesterday at a total cost of $290 for the entire set-up (batteries not included). This includes: one color CMOS mini spy camera with audio, one color CMOS mini spy camera without audio, power clips, one 7.2" color LCD screen with built-in speaker, and one 1.8" color LCD screen. The two systems will have to operate independently of each other so that there is a back-up if one has a power failure. I plan to hook up a video camera to record some runs since I'll have audio capability. If I don't end up using too much of the WISIL site's storage capacity, maybe Warren will put up a link to allow people to see what it's like to go screaming down a Nevada highway at stupid speeds.

I also have begun shaping the vertical pod for the cameras. It looks like a vertical stabilizer. Pics of that will follow.

Customers have been coming into the factory to pick up their fountains and waterfalls that I design while I have the fairing pattern on the work-bench. Some don't quite understand why someone would want to go to all the trouble to build such a bike. Others love it. The best part was when two bikers from the custom Harley Davidson/Chopper shop next door came to pick up a waterfall for the owner's wife. They both looked at me (with their long beards and mustaches and dozens of tattoos with skulls and knives depicted) and said, "You're crazy. You're nuts, man. You're on another level. We had no idea a wacko was next to our shop!" Hah! I'll never forget that one.

Man, what have I gotten myself into... I feel like I'm on the Lunatic Fringe!

5/25/03
OK, so I made a mistake. I put the base plate back into the canopy pattern. I got to thinking about the heat generated during making the mold for the canopy later on and realized that there might be a chance for the piece to slightly warp due to heat. So, while I was in there, I reinforced the inside with fiberglass (just like I had done to the lower airfoil section of the fairing). I re-installed the baseplate using 1 1/2 oz chopped fiberglass mat. It's back to being a little heavy again, but better safe than sorry! The last thing I need is to end up with a tweaked part coming out of the mold. I can sleep better now.
I attached a picture of me on my old Turner. I used this photo to study my proportions to make sure that I'd fit into the airfoil shape. My Turner has been greatly modified since this photo was taken. It now has
above-seat-steering and a rear suspension that I stole from a Specialized mountain bike frame. I also crafted and installed a custom carbon fiber seat that sits 3" lower than stock. All that's left of the Turner now is the main boom to half way under the seat.
I used to be concerned that the width of the streamliner bike would be a problem. I look at other streamliner bikes and see 16" widths, etc. For one thing, there's no way I could fit into one of those! My shoulders are 21" wide with my arms forward. I read about one of the human powered airplanes and found some information that inspired me. The designer of one aircraft pointed out that many folks make certain parts of their craft skinny (like the fuselage where the pilot resides) to minimize frontal area... at the expense of lower drag #'s and better aerodynamics! Ah, this gives the 'beefy one' hope. I have been faithful to the foil shape for this bike without altering it in any way to save on frontal area. The q-factor for this bike will be around 12.4" wide. I'll actually have about 1/2" of clearance for my shoulders and plenty of room to the sides of my head. What do you think, should I add a stereo system to get the ol' adrenaline pumping during runs down the highway? How about a sub-woofer? Yeah! 
5/29/03
In the pics you can see how using the long board with rough sandpaper has revealed some low spots. I had fogged a very light coat of sandable primer onto the canopy prior to sanding. This step is done after hours and hours of shaping and leveling as best you can.

The next photo shows how I applied red spot putty to all the grey areas. After sanding this layer down the canopy was much closer to being very level. I performed this step about four times. Each time the areas that were revealed as minor low spots were fewer until spots stopped showing up. Man, what a chore!

If you look closely you may see some of the evidence of the original grid showing through as variations in putty color. It's evident because there is hardly any putty over the grid structure! I've sanded and leveled until the putty is aligned with the grid and all low spots are gone.
This shot shows the canopy just prior to blasting it with a high solids primer that fills all the fine lines left by the sandpaper. This primer will be wet sanded later with 240 grit, then 400. It'll be primed again with a lighter coat then hit with 400, then 600 grit. The primer is a urethane
primer (sometimes called banana primer because it smells like bananas). It builds very quickly and isn't prone to running. In these photos almost a quart has been applied. The primer is expensive at about $180 per gallon, but there is no comparison to the quality and incredible time savings compared to using a bunch of cheapo spray-can primer.

I inserted three wooden dowels between the canopy and airfoil layers so that the primer wouldn't bridge the seam between the two.

It feels so good to have this rascal under a coat of primer. The hard part is done! The canopy was incredibly time consuming to shape compared to the airfoil sides. My most difficult realization during canopy shaping was that one side's putty was slightly thicker when I thought that I was all done.
How could this be? Ah, hah, I favored my right arm during sanding one side and my left on the other. I'm right handed, so the side that favored the
left hand had a slightly thicker coat. It took almost 6 more hours of sanding and checking to bring the canopy into symmetry. The thicker side was
only 1/8" thicker, and within my foil experiment's no-fault zone, but there's no point in making a lop-sided canopy when a few more hours will
dial it correctly into the foil shape and reduce risk of messing up the laminar air flow quality that I've worked so hard to develop. 
With Matt Weaver's coaching and all my experimenting I've got over 100 hours of study into the development of a successful foil shape that would fit my proportions. I'm not going to mess it up now... no way!
All that's left to do is to add the v-hull shaped bottom and finish the camera pod, then it's mold time. The bottom actually relates to the foil shape somewhat, so hopefully there will be some laminar flow to the sides of the wheels. If all I've accomplished is an incredible amount of laminar flow over the surface of the canopy and sides, the bottom can go ahead and kick into turbulence like other bike's bottom sides. Hey, there are wheels
sticking out down there, how much more laminar can you get with a simple design like this?
6/18/03
I placed a 1/4" thick non-tempered hardboard board with the height and profile that I need to form the 'keel' of the v shaped bottom. This will serve as a sanding guide as I bring the rest into line with the profile of the foil shape. I glued alignment sticks to the sides of the keel to support the cardboard during its placement.

Cardboard was then superglued into place and then a coat of resin was applied to rigidize it. Tomorrow I'll place aluminum strips alongside the foil sides to give me an edge to pull against when I apply the putty. The
cardboard helps to minimize the amount of putty needed to get the shape.
The canopy is completely done and ready to mold. It should be molded
sometime next week! The rest of the fairing will probably be molded as well.

I've decided to use a laminar foil designed camera mount as well and that is
shaping up nicely out of balsa wood. 
6/21/03
The photos show the aluminum taped into place to serve as a swiping guide for the putty. It is called roofing tin at hardware stores, but obviously it's not tin. =)

The polyester putty went on very quickly. I used about 2 1/2 gallons mixed in a five gallon bucket. I make the putty myself using polyester resin, Featherlite 1000 brand filler (lightweight particles designed to cast kitchen countertops), and Cab-o-Sil (amorphous fumed silica) as a thickening agent. 

It is catalyzed with MEKP which makes the polyester harden. It helps to catalyze the resin prior to adding the other ingredients, otherwise the putty can be rubbery for a while. It mixes up easily using an air powered drill with a paint blender attachment. Wear a breathing mask.

I spread it with a large mixing stick and won't have to do a whole lot of work to smooth it well. This part of the fairing is a piece of cake. Hah, the putty looks like cake icing anyway. Next, I'll go through body working techniques already outlined above, using Bondo and spot putties, then primer.

The camera pod is made from balsa wood airplane wing sections available at any good hobby shop. The ends will get cut off when I adjust the length and  it will be fitted to the canopy after molding.

Hoo-wee! 'Not too much more to go!

By the way, the semi-linear drive manufacturer has expressed interest in supplying me with a system. We're working out details now. It looks like it's a possibility that I'll have the system in time for the race. We'll see how it goes!
7/11/2003
I gave the sculpting of Lunatic Fringe's pattern a break to think about things before I went to molding. I'm glad that I did. I was on a super fast track to completion, but felt the need to back away to make sure of things.

One night I awoke at 3 am with a thought. I had been running a wind tunnel in my head during a dream. I see things in 3D really well in my thoughts and can rotate things around like in a computer animation to study them. I had realized that as the pressure built upon the vertical airfoil sides of the bike, it would tend to move toward the bottom of the bike to equalize the pressure. This would result in a loss of laminar air flow at the bottom 1/3 of the fairing's sides.
I In order to alleviate this problem, and maintain better laminar flow along the sides, I've added a horizontal set of fins to keep the air in place along the sides. This is similar to the little winglets used at the ends of
airplane wings to keep the air in place. I constructed them using balsa wood from a local hobby shop and blended them in using Bondo.

Have I done the right thing? I think so... we'll see.

I've been saying for a while that the molds would be done soon, but I feel like it was worth the wait. I feel confident in making the molds now.

Bike parts are on order! Ajo Bikes (Tucson, AZ) is bringing in suspension hubs, 451 20" wheels, Stelvio tires, intermediate gearing, front fork, and disc brakes. Vibration isolators from Sorbothane have come in and look to be of high quality. The camera system works well.

Things are really falling into place! It's going pretty well considering only one person is designing and constructing the entire bicycle. It would have been next to impossible for me to complete this in time for the race without help from sponsors.
They covered the cost of most of the expensive goodies. Composites One (resins, etc.), Hexcel (carbon fiber), Ajo Bikes (Tucson, AZ - bike parts, advice), TRB Systems (semi-linear drive system)and Sorbothane (vibration isolators) are some of them.
The bicycle frame building class that I took at UBI (United Bicycle Institute) has been incredibly valuable as well. I wouldn't have even looked at going in this direction with the aerodynamics without Matt Weaver's teachings.

I may decide to make the bike frame using carbon fiber tubing that I have sitting around here and from parts of a carbon fiber tube bike frame experiment that I had done years ago. I may make the seat an integral part of the frame, using honeycomb to dramatically increase rigidity.

The manufacturer of the semi-linear drive system has said that the parts are being sent. I'm excited to receive them and give them a thorough test. One set will go on my training bike for training and testing. The other is
destined for Lunatic Fringe. The cranks that come with the system are 205mm. I may increase their length to 300mm. The semi-linear drive system can be seen at: www.trbsystems.com The inventor, Mr. Byung Yim, is the engineer that marketed the Alenax drive system in the 80's. His new system is really unique and is currently being marketed in China.

7/14/03
They (TRB Systems) actually sent me two of them like I'd asked. I can tell that the quality is very good. I'll put one on my regular 'bent soon to begin training with it. They come with 205 mm cranks, but I may extend them
to 300. They are very simple in design and easy to operate. 

They're quite unique. Each foot can pedal independently in a back-and-forth or circular motion. The idea for Lunatic Fringe is to get killer leverage on the crank and then ramp up the gearing with intermediate drive (which TRB supplied me with as well).
7/21/03
I took an old Turner hard shell seat that I had laying around and put it
inside a plastic bag. I then placed it next to the fairing plug, filled the
bag with 4 lb density urethane foam, and sat on it! After it finished
expanding (3-4 minutes) I hopped off and had a perfectly shaped seat for my back. The only thing left to do is to sculpt a neck rest. The blob of foam in the picture will be shaped tomorrow during some dead time. This foam/seat combo will be the mold for the seat of Lunatic Fringe.
This picture of me standing next to the completed pattern shows me wearing some of my old clothes from when I was a hefty 265. I use those size clothes
for working in the shop now (I've got a bunch of 'em left over). Since I've been working out the legs a little, my weight loss has stopped even though I'm still hitting the protein hard, and I've even gone up three pounds. Ah, well, maybe I won't see 200 after all!

I've gotten to a point where I can't safely move the pattern around without damaging it. I have a worker bee showing up tomorrow morning to help me
shoot the molds. Pictures of that process will follow very soon. The plan is to pull the molds off of the patterns on Sunday and lay up the fairing Monday-Thursday. I'd like to get the parts pulled next weekend.

A 90 tooth and 72 tooth chainring are slated for machining next weekend. I'm getting ready to jump all over making the frame! Hey, does it look like I'll actually fit inside the thing? Hmm... =)

 
Click here to go to Page 2 - Making the female molds and actual fairing

   

Jeff Bales
Tucson, AZ

 

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