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 Streamliner Fairing Construction and Design

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T O P I C    R E V I E W
Matthew Martin Posted - 09/19/2017 : 20:42:30
Hi, I am a high school student who has been interested in the concept of streamliners and their construction. The question that has been bothering me is not knowing how to attach a windscreen (canopy;plastic view port) to a fiberglass fairing almost seamlessly without the use of tape. I have been working tirelessly on a cad model of a bike that I hope to build. The bike is a somewhat practical streamliner that is high enough to be moderately visible in traffic. I need to be able to attach a large vacuumed formed windscreen to go with my design.As I don't know how to insert my image ( not online so no url) my windscreen needs to be similar to the velotilt
25   L A T E S T    R E P L I E S    (Newest First)
Speedbiker Posted - 12/11/2017 : 20:19:37
Matthew, that Moby was built in the 80s. Bikes weren't very light back then. Steel frames, wet laid up bodies, and heavy components. But that bike is still being raced competitively.
I think your design peaked when it was short wheel base. Something of a super F-40, which as many will attest is the most successful two wheeled velo ever.
alevand Posted - 12/09/2017 : 18:56:01
Yes, fiberglass, 74 lbs is heavy. A coroplast lwb is 45-50 lbs with 15 lbs of coroplast.

quote:
Originally posted by Matthew Martin

steel framed and fiberglass fairing? Just asking because the fairing scale project says its only weighs 74 pounds...is this accurate? Seems light for an 11ft streamliner



C:
Tony Levand
Matthew Martin Posted - 12/09/2017 : 18:16:21
steel framed and fiberglass fairing? Just asking because the fairing scale project says its only weighs 74 pounds...is this accurate? Seems light for an 11ft streamliner
alevand Posted - 12/09/2017 : 14:06:54
No, its steel framed.

C:
Tony Levand
Matthew Martin Posted - 12/09/2017 : 11:10:47
ok thanks... Is the Moby Cf?
warren Posted - 12/09/2017 : 09:28:53
Yes, that bike would be heavy, itís just an example. You could build something similar out of CF that would be much lighter, like the Blood, Sweat and Gears LWB Ďliner that Rick Wianecki built.

Unless you are building a trike, you canít ride slow enough to make the extreme steering angles useful.
Matthew Martin Posted - 12/09/2017 : 07:11:08
So what you are saying is not to allow the wheel to turn any more than 45 deg? The current design allows enough space at the nose for the wheel to move 45 deg.
alevand Posted - 12/08/2017 : 19:48:15
A monotube frame is the easiest to make, it doesn't need all the zig-zags, one bend under the seat is all that's needed. The hard part is finding thin wall large diameter tubing. I used 2.38 x .049 mild steel, and it was flexy enough to provided a smooth ride, but dint corner as well as a Bacchetta stick bike.
It depends how big the hole is for the front wheel, and how wide the nose is. +/- 30 degrees is about the practical limit, +/- 22.5 degrees more typical, so multiply the wheel base by 2 or 3 for a turning radius, 80 x 3 = 240, 20 feet, it would take 4 lanes for u-turn. 80 x 2 = 13 feet, 2 1/2 lanes for a u-turn. With a bigger nose, could could get it down to a 2 lane u-turn. You don't want to turn the front wheel more than 45 degrees. To figure the width of the nose, multiply the tire diameter plus the rake by the 2 x sine of the steering angle. So a 30 degree steer would be one tire diameter, +/- 1/2. Having the axle behind the steering axis and a steep head tube angle helps some, but the the steering tube stick up high.

C:
Tony Levand
Matthew Martin Posted - 12/08/2017 : 17:08:31
Thanks but would a frame like the Maurader not be too heavy?



And does any one know the turning radius of the Moby streamliner... I am concerned that a 10ft long streamliner will not be able to turn around on the street and the Moby is 11ft, and on the fairing scale project it says that Mr.John commutes with it...so I am asking if it can turn well?
warren Posted - 12/08/2017 : 13:48:39
Looks good. Something like the Maurader would probably work.

Matthew Martin Posted - 12/08/2017 : 13:40:29
any suggestions on a lwb frame design?
Speedbiker Posted - 12/08/2017 : 09:43:28
Good job. Keep after it.
Matthew Martin Posted - 12/07/2017 : 19:41:52
As I was getting ready to finish my past project and begin this one I realized an overlooked mistake...I had left too much unnecessary space in the toe box of the fairing. As result I just decided to restart with a new perspective and with your advice. The result was this:


This new design is much faster and the Cop is in line with the riders body. It has a frontal area of .528m^2 and a cd of .11-.13 depending on wind speed




Once again any advice on the shape is welcomed.
I am working on the Coroplast model as I need to get that done before school lets out for Christmas, as I plan to use the break to build the plug.


I also need advice on a lwb frame design. I dont know much about "fast" lwb designs. I also dont want a complicated frame, ant suggestions for the frame? This is my geometry:


Jerry Posted - 10/31/2017 : 08:07:16
See Richard Myers camping pad build here on this site.
alevand Posted - 10/31/2017 : 06:43:45
Ive used a camping pad to make a removable deck cover. That way I could roll it up for storage. Its PEX, same stuff as Zote foam, but thicker and smaller pieces. See John Tetz's pages on Zote foam: http://recumbents.com/mars/pages/proj/tetz/manual/0intro.html

Very light, offers some protection, but not skid resistant, has an insulation R-value of 2

C:
Tony Levand
nickyfitz Posted - 10/30/2017 : 18:28:10
Don't laugh but I get a lot of good use from foam camping mats. Light, cheap, and readily available. Not as stiff as coroplast, but the plus side is the suppleness makes it easy to form - even into tight radii - and with some judicious cutting/shaping can be formed into 3D curves.

Nick

Previous bikes:
https://www.flickr.com/photos/139728134@N08/albums/72157673027547665
Speedy Posted - 10/29/2017 : 16:42:02
Cardboard works out fine to create a test fit version.
Coroplast is lighter, stronger, better weather resistance.
alevand Posted - 10/29/2017 : 10:15:41
The nose is the hardest part to make from coroplast. It can be formed to a radius more than what shown in the cad, doesn't need the facets, but then again it easier to use facets and joint cad pieces like a kit. I use a heat gun. You can get 4x8 sheets from print supply for $20. You'll get a lot of internal reflections with a windscreen that horizontal. Its nice to be able to see the road in front of the bike for stuff like pot holes and rocks, so the nose shouldn't be higher than necessary.

C:
Tony Levand
Jerry Posted - 10/29/2017 : 08:59:18
I just bought 5 sheets of coroplast at Home Depot for $19.57 each. They only carry white.
Speedbiker Posted - 10/29/2017 : 01:58:30
Coroplast was $20 a sheet last time I checked. It's a joy to work with, unlike cut up refrigerator boxes. Well worth it. And it will hold up thru all testing.
Matthew Martin Posted - 10/28/2017 : 21:41:05
Been designing a fairing that could be made with coroplast. Uses 6 sheets but the cuts are pretty easy.



Used pepakura designer to design the cuts


Possible design for the bike fairing.

Are there any cheaper options besides coroplast for a mock up fairing?
Has anyone tried cardboard? I am not concerned with durability or weather proofing but just want to get a general idea of what this fairing feels like.

Suggestions welcome
nickyfitz Posted - 10/19/2017 : 13:17:40
For its maiden voyage this bike took me 1450km across the mountainous Massif Central of France and back. Weighing in at approx 15kg and with 12kg of luggage on the back (of which 3kg was tools, just in case....!) we didn't break any speed records but I never noticed any front wheel slip. And we went up some pretty damn steep hills I can assure you!

I've looked up the notes in my project file and I had measured the weight distribution with me on board (but no luggage) as 58/42% front/rear. So with 12kg or so of luggage behind me that would give approx 50/50 distribution.

It was my very first experience of bike touring, and the SWB FWD format was great. If ever I found myself in the wrong gear when starting off (eg on a hill) it's so easy to stand up, lift the front end, change gears and spin the front wheel to select a better gear. The big design error was to put the bottom bracket so high. I had intended to replicate the same body-hip angle as a DF bike thinking that this would aid my unadapted transition to "recumbent legs". In practice it caused early onset of lactic acid accumulation in my thighs and pains around my knees, and the seat angle was a tad too high so I also suffered some recumbent butt. Great trip though :-)

Nick

Previous bikes:
https://www.flickr.com/photos/139728134@N08/albums/72157673027547665
alevand Posted - 10/19/2017 : 06:33:47
Hi Nick, I like your bike, how is your SWB, FWD bike for touring? Do you ever loose traction up hills?



C:
Tony Levand
nickyfitz Posted - 10/19/2017 : 05:05:45
Matthew, you seem to have a very wise head for a young man at high school. And I like your favourite quote in your profile. You have already impressed us with your inspiration and the seriousness of your approach, now it's time to get down to the perspiration!

You clearly understand the scale of the challenge you have set yourself and you mention that a "successful" result may be hard to achieve. But think of it more in terms of the process than the product. However your project turns out you will learn immensely useful things along the way. And even if the result doesn't meet your own very high standards, nobody on this forum is going to denigrate your achievement. We know how hard it is to get it all right and, whatever your high school peers may say, you will have won our admiration for your efforts. Plenty of people here to applaud you and try to help you overcome any issues you encounter. I personally am sure you will impress us all.

Go for it! And send us lots of photos! :-)

FWIW, in response to your question to Jerry about cross wind effects, I too found my first test ride in windy conditions very scary! I removed the fairing at the nose and tried again. It was slightly less scary!

So I took advice from Warren and Speedy on the importance of getting the CofG as far forward as possible and the CofP as far back. It's not always easy! Also Tony Levand suggested I lower the nose so as to encourage airflow to go over it rather than around it. Again, not so easy. But I completely rebuilt the front of my frame with a smaller wheel, revised fork geometry and shorter cranks, and I put the rider in a more upright position with the handlebars in front of my knees so as to move my body mass forwards. If you compare the recent photo above to earlier pics in my previous bikes link below you can see how much I managed (to my great surprise) to improve the aerodynamics at the front end. The bike is now much lower and 18cm shorter at the nose, and only 6cm taller at the highest point (the rider's head). I can't tell you yet what difference that makes out on the road because with moving house and other commitments I haven't had the time to ride it out in windy conditions. But in any case, as Jerry said, unless you are intentionally testing aerodynamics you don't normally choose to ride a streetliner when it's windy!

Good luck!

Nick

Previous bikes:
https://www.flickr.com/photos/139728134@N08/albums/72157673027547665
Jerry Posted - 10/18/2017 : 15:39:45
Sounds like you have it going on there and understand the principles Matthew. Good for you.

I was riding a swb Lightning Phantom with a Lexan wind screen and a coroplast body. I had left off the top and bottom sections of coroplast because I knew it was going to be windy out. The wind was out of the west at 22-25 mph. I was headed south and leaning to my right to balance the coroliner against the wind, when the wind shifted without warning from the west to the east and at around 45 mph. It knocked me over before I could react. I am a fairly strong and agile person, but with shifting winds and a full fairing, you are going down. I would have been alright except my hip hit the crown edge of pavement, that is the rounded part of pavement. Maybe, and that is a big maybe, if the middle section had been spandex, it might not have knocked me over. I really don't think so though. It happened so fast, kind of like the way the wind acts in a tornado. I am not expert enough to say if you can design for this situation. Most liners stay home when the wind is blowing very hard.

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