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 Fairing for my Greenspeed SLR
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Jerry
human power supergeek

USA
1381 Posts

Posted - 03/04/2019 :  07:55:03  Show Profile  Reply with Quote
Started on this Thursday night. I gave away and sold over 99% of my tools when I moved from Mo to TX. I sure wish I had my work table with holds downs and stops, & dogs, vises, my 3" wide x 1/4" thick capacity bender for flat bars, and the rest of my tools. Anyway headed to get some more zip ties so I can finish the cockpit and tail. The cockpit will be removable and so will the top tail section.

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Jerry
human power supergeek

USA
1381 Posts

Posted - 03/04/2019 :  20:20:18  Show Profile  Reply with Quote
The rear is mostly done. Tony thought I couldn't see well enough so I put a small window on the lower front so I can see right in front of the nose. I think I'll put one on the other side too.


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Upright Mike
human power expert

USA
3847 Posts

Posted - 03/04/2019 :  22:07:39  Show Profile  Reply with Quote
Awesomely quick (no pun intended!) fairing Jerry!
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Jerry
human power supergeek

USA
1381 Posts

Posted - 03/05/2019 :  06:58:51  Show Profile  Reply with Quote
I decided at the last minute to try and get it built for the HOT rally held at Easy Street Recumbents in Keller, TX about 2 miles from my house. It didn't work out because of other distractions and other things the boss lady thought was more important for me to do for her! Ha ha. This is the prototype build. I am going to build some 406 wheels instead of these 349wheels to get some ground clearance. Then rebuild the fairing with a more aero nose. I am going to sneak this in at the Dallas Senior games on the 16th of this month. The rules states no aero bars and no fairings. All 100+ road bikes had aero bars last year. Either take all aero bars off or I am riding this. I hope it is faster than the build!
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Jerry
human power supergeek

USA
1381 Posts

Posted - 03/05/2019 :  14:06:03  Show Profile  Reply with Quote
Getting close to getting done.

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Jerry
human power supergeek

USA
1381 Posts

Posted - 03/05/2019 :  21:52:07  Show Profile  Reply with Quote
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Jerry
human power supergeek

USA
1381 Posts

Posted - 03/06/2019 :  11:38:52  Show Profile  Reply with Quote
Finished it this morning getting ready for test ride. I raised the bottoms of each side 3/4", painted the top of canopy silver flake, and attached the canopy. It fits like a very tight glove on me. Need to cut the holes for the sliding windows for air.
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Edited by - Jerry on 03/06/2019 11:39:44
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alevand
human power expert

USA
3389 Posts

Posted - 03/06/2019 :  12:01:58  Show Profile  Visit alevand's Homepage  Reply with Quote
Well, not so tight that you can't wave. Looks very low, almost touching the floor by the wheel well, did you take into account tire and frame deflection from your weight ? Should be fast. Did you order the 406 rims and spokes? I get my spokes from a Dan's Comp in Indiana. https://www.danscomp.com/products/435915/Sapim_Stainless_Double_Butted_Spoke.html

C:
Tony Levand
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Jerry
human power supergeek

USA
1381 Posts

Posted - 03/06/2019 :  12:35:46  Show Profile  Reply with Quote
If I hadn't turned my shoulders I couldn't have waved. A helmet just barely touches the canopy. I am waiting until April to start the 406 wheels. I raised it 3/4" because of deflection. It has about 1" clearance on the sides and 3/4" until the skid plate. Apparently someone before me put some kind of epoxy on the aluminum skid plate. I think I will grind it off tomorrow.. I will make a removable more aero nose and spandex wheel pants. Hard for me to breathe inside it. Maybe I'll run my snorkel tubing through the top of canopy so I can breathe better.
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Toecutter
Starting Member

USA
32 Posts

Posted - 03/06/2019 :  13:23:03  Show Profile  Reply with Quote
That looks good. That ground clearance wouldn't work for the kinds of roads I've ridden on, but I think it will be faster than your previous build on the Performer.
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Jerry
human power supergeek

USA
1381 Posts

Posted - 03/06/2019 :  14:29:44  Show Profile  Reply with Quote
Back from the first ride. I will start on the 406 wheels right away. Man, it bottoms out on these Texas roads and the trail. A few other issues, my right toe hits, left knee touches sometimes, and I will bring the clear nose back towards the rear about 4-6 inches to make it easier to see traffic lights! It is pretty quick even when my jacket was between the chain and floor! It is very noisy inside.

With the 406 wheels and a few minor changes it will be a keeper. I am still making a more aero nose that is removable for transport. Also spandex wheel pants.
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Jerry
human power supergeek

USA
1381 Posts

Posted - 03/13/2019 :  20:20:36  Show Profile  Reply with Quote
I have fixed the issues of my feet, knees, tires hitting or rubbing on the SLR build. Now re-doing the nose something like this. Still need to put spandex over a couple of small holes and put wheel pants on. Maybe spandex or coroplast wheel pants. Also have about 1/4"-3/8" more ground clearance.


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Edited by - Jerry on 03/13/2019 20:24:23
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Toecutter
Starting Member

USA
32 Posts

Posted - 03/13/2019 :  23:45:54  Show Profile  Reply with Quote
The design in the image above that you want to base your vehicle's nose off of was ridden to over 30 mph top speed by a 13 year old kid. That's as fast as you recorded yourself going in your first shell for the Performer trike!

Out of curiosity, what kind of software, web pages, and/or information do you reference in order to shape your body shells for drag reduction, and how do you know they will provide the best possible outcome? I'm trying to figure out how to improve mine as much as possible. Your shells are fast, but do you know if they are as fast as they possibly can be given your design and practical constraints? How do you know there isn't an extra 10-20% more gains to discover with some tweaks?
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Jerry
human power supergeek

USA
1381 Posts

Posted - 03/14/2019 :  07:48:04  Show Profile  Reply with Quote
I use the time honored SWAG method. Scientific wild ass guess! Software to me is an old tee shirt. My other corovelo is my touring bike. I am a 13 year old too, plus 53 years!
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Toecutter
Starting Member

USA
32 Posts

Posted - 03/15/2019 :  14:52:19  Show Profile  Reply with Quote
When you make your wild ass guesses, is there any algorithm or methodology you use to determine your shape? I'm just curious to see WHY your velomobiles are shaped the way they are. Random guesswork generally does not yield good results for aerodynamics(this is especially true for automobiles), so I'm really curious as to what you know and how you are applying it.

There's a lot I could learn from you and your builds somewhere.
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Jerry
human power supergeek

USA
1381 Posts

Posted - 03/15/2019 :  20:07:01  Show Profile  Reply with Quote
I look at other designs and read a lot. I try things and if they don't work, re-build it.
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Toecutter
Starting Member

USA
32 Posts

Posted - 03/15/2019 :  22:46:44  Show Profile  Reply with Quote
Do some tuft testing when you can. My guess is that you don't have the rear shaped properly and that it is tapered too steeply. It's only an educated guess though.

I like the design, regardless. I look forward to a video of you hauling some ass in it.
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alevand
human power expert

USA
3389 Posts

Posted - 03/16/2019 :  07:53:53  Show Profile  Visit alevand's Homepage  Reply with Quote
I like the tuff idea. Do it with the wheel skirts on. We had a tuff test on the ecomodder meetup and my Saturn was the only car in the videos with attached flow along the whole body. They were all impressed. Choose your side wind direction carefully. Id say theres a circulation bubble on top of the nose and the top part of the back is ok, maybe the bottom part of the taper can start sooner. 15 deg is the usual rule. Its easy to armchair an existing build. Good luck at the TT.

C:
Tony Levand
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Jerry
human power supergeek

USA
1381 Posts

Posted - 03/16/2019 :  20:11:00  Show Profile  Reply with Quote
I do tuff tests just like I did with my sailboats. My shoulders, hips, and hands touch the sides now and can't start taper any sooner. The rear taper is fine. It is pretty close to the taper of the DF velo I checked out several times including today at the TT. The top has been re-done and the nose is getting re-done. When I get it done where I want it, we'll see how it performs. I need to find my box of wool yarn. Haven't seen them since I moved last year. I think I have like 25 rolls of it.
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Jerry
human power supergeek

USA
1381 Posts

Posted - 03/18/2019 :  16:39:10  Show Profile  Reply with Quote
About the best I can do for now. Too tired to test it. Maybe tomorrow I will take it out.




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Jerry
human power supergeek

USA
1381 Posts

Posted - 03/19/2019 :  20:35:26  Show Profile  Reply with Quote
It is pretty fast. Waiting on my new 406 rims so I can build 406 wheels for it. It bottoms out way too much on Texas chip seal roads, dips, and uneven pavement. Will have to re-build the wheel wells to fit the new wheels.
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Toecutter
Starting Member

USA
32 Posts

Posted - 03/20/2019 :  01:25:38  Show Profile  Reply with Quote
I really like that nose. This thing should get you to over 40 mph I would think.

How did you form that nose in coroplast?

Edited by - Toecutter on 03/20/2019 12:19:24
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Jerry
human power supergeek

USA
1381 Posts

Posted - 03/20/2019 :  13:49:56  Show Profile  Reply with Quote
It's fiberglass!
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warren
human power expert

USA
6403 Posts

Posted - 03/20/2019 :  21:16:46  Show Profile  Visit warren's Homepage  Reply with Quote
Looks good Jerry. I'm happy you found a good use for that fairing.
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Jerry
human power supergeek

USA
1381 Posts

Posted - 03/20/2019 :  21:40:04  Show Profile  Reply with Quote
Thanks Warren. I think it works well with the fairing even though I took the grinding wheel to it!
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Toecutter
Starting Member

USA
32 Posts

Posted - 03/22/2019 :  03:57:09  Show Profile  Reply with Quote
I didn't realize you used the same nose cone from your other build. This is the perfect application for it. I look forward to seeing what you can do in it. It may end up being as fast or faster than your streamliners.
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