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alevand
human power expert

USA
3541 Posts

Posted - 12/23/2015 :  14:50:12  Show Profile  Visit alevand's Homepage  Reply with Quote
Made front skirt from orange spandex. I don't know how to fill up the big hole for the wheel, makes a ram air scoop.. Too windy out for a test ride tonight, 30 mph gusting to 40. Narrowed the fairing 2 inches at the handle bars and lowered 1 inch, much more wind in the face. Toe is rubbing on right bulkhead. Weighed bike, 48 lbs dry.

I could do 27 without the nose downa hill that I could do 35 with the original full nose 451 fairing, (35/27)^1/3 = 9 percent increase in drag, assuming drag is cube of air speed, but could be a higher power going down hill, since the faster you go the faster the potential energy is use, but would be less that quartic, that would make it 7%

The fabric is glued to the fork, which is near the steering axis, so I don't expect much more wind steer. Seemed fine up and down the road in this afternoon's side winds.

Bike:

Front skirt:

Front stowage:

Rear Stowage


C:
Tony Levand

Edited by - alevand on 12/23/2015 15:27:16
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Grant-53
recumbent guru

USA
554 Posts

Posted - 12/23/2015 :  17:21:27  Show Profile  Reply with Quote
I won't say people can't do it if they are careful and I have used a motorcycle touring shield on an upright as it has little side area. Like the front wheel cover the need is to have more fin area behind the steering axis. With high winds you need every advantage to maintain control including rounded sides.
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alevand
human power expert

USA
3541 Posts

Posted - 12/24/2015 :  05:08:09  Show Profile  Visit alevand's Homepage  Reply with Quote
If I make a rigid fairing connected and pivoting with the forks back, then side winds would cause the fork to steer into the wind, canceling the force steering it with the wind from the product of caster and side wind on the main fairing.

C:
Tony Levand
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alevand
human power expert

USA
3541 Posts

Posted - 12/24/2015 :  12:07:20  Show Profile  Visit alevand's Homepage  Reply with Quote
I went for a test ride today and I am not happy with the cloth front end. I am cruising at 16 t0 17 mph, where it was 18 mph with the 451c wheel outside and 20 mph with the full nose. I went down the hill at 41.5 mph, exactly the same speed as with out the cloth. I am sick of working on this bike,it has consumed all my free time for a month. It has a slow speed wobble. I am canceling my grandiose trip south, the weather is going to be cold and rainy anyway for most of the way. I want to make a new Carp, 10 lbs lighter, 38 lbs with fairing. Either aluminum or composite. I'll see how Warren's bike turns out.

C:
Tony Levand
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Jerry
human power supergeek

USA
1475 Posts

Posted - 12/24/2015 :  14:43:02  Show Profile  Reply with Quote
Sorry about your situation with the bike and trip Tony. I am sick and not riding or much of anything right now. Maybe we can hook up and ride sometime next year. 2016 has to be a better year! I'll be working on my LWB touring bike and building a new low racer and rebuilding the Actionbent. Have a Merry Christmas.
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alevand
human power expert

USA
3541 Posts

Posted - 12/26/2015 :  05:56:05  Show Profile  Visit alevand's Homepage  Reply with Quote
I was thinking how to improve the front, and then serendipity struck. On the virtual pivot, the fairing could be attached to the links, no gaps, or fabric needed, just hinges. I could have a narrow hub to reduce the ram air opening. On one hub that I made, the width is 3 3/4 to 2 1/4 inches, 40% narrower. That would make a smaller cross sectional opening than the 451 wheel. VPS or Duplex could be on the new Carp.

C:
Tony Levand

Edited by - alevand on 12/26/2015 06:09:27
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Jerry
human power supergeek

USA
1475 Posts

Posted - 12/26/2015 :  06:51:16  Show Profile  Reply with Quote
Good luck with it. Hope it works out for you.
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Speedy
recumbent guru

USA
909 Posts

Posted - 12/26/2015 :  11:11:38  Show Profile  Reply with Quote
Some observations

A long time ago I read a white paper written for a HPV study that concluded that a 8 inch diameter hole on the leading edge of a fairing completely negated the effect of the fairing.

The top of an exposed front wheel is a significant source of overall drag.

Aerodynamic disturbances that began at the front of the shape can not be corrected further down the shape.

A clean, smooth leading edge is most important part of the shape.

Steve Delaire

http://molten3d.blogspot.com
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alevand
human power expert

USA
3541 Posts

Posted - 12/27/2015 :  06:26:08  Show Profile  Visit alevand's Homepage  Reply with Quote
Hypothesis A is not correct, unless you mean a hole all the way through, where the wind is blowing on the rider.

There is a fender, so hypothesis B is out.

A little ice on an airplane wing leading edge will cause it to stall and crash.

I may try a coroplast nose, with a smooth inside channel for the wheel and outside curved to be tangent with the body at the seam.

I am heavily weighed toward a suspended, enclosed 451 front wheel on the new Carp.

My other option is to put the front wheel out front another 7 inches. That would make it 90 inch wheel base, but I would have an enclosed nose that could be filled with cargo gear as ballast. I am leaning toward this, I have gone this route in the past.



https://www.youtube.com/watch?v=_7naGcGrBQI

C:
Tony Levand

Edited by - alevand on 12/27/2015 08:55:19
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alevand
human power expert

USA
3541 Posts

Posted - 12/27/2015 :  10:01:53  Show Profile  Visit alevand's Homepage  Reply with Quote
I have this nice aero carbon fork and deep v rim. is there a way to put canti-studs on the carbon fork or are there rim caliper brakes that work as well?



C:
Tony Levand
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warren
human power expert

USA
6470 Posts

Posted - 12/27/2015 :  16:13:40  Show Profile  Visit warren's Homepage  Reply with Quote
You can get long reach side pull brakes that work well.
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alevand
human power expert

USA
3541 Posts

Posted - 12/27/2015 :  16:59:13  Show Profile  Visit alevand's Homepage  Reply with Quote
I Have tried dual pivot brakes, but stopping power lacked compared to v-brakes with road levers. After moping around all day, I decided to cut up the front end once again (notice a pattern here) and extend the front wheel out 7 inches. I think I can do this without removing the whole fairing. I have a piece of 2 inch x .049 x 9 inch tube, from a swingset, that's not galvanized. I wired brushed the epoxy paint off both ends and removed the top part of the bulkhead. I'll start cutting after dinner. This should give me a nice clean nose behind the wheel, with no moving parts. I am thinking the lost foam method with 2 layers of kevlar, though Im not sure I can cut the stuff.. I can stow water and other heavy items in the nose.

... Turns out the tubing is 2 x .042, 19 gauge, it's .049 with the paint and burrs. I am going to use one piece and a head tube from the motobeacon instead of trying to splice it... later.

C:
Tony Levand

Edited by - alevand on 12/27/2015 18:47:06
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warren
human power expert

USA
6470 Posts

Posted - 12/27/2015 :  19:01:05  Show Profile  Visit warren's Homepage  Reply with Quote
Just sharpen the scissors and resharoen them when they stop cutting well. That's what I did...
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alevand
human power expert

USA
3541 Posts

Posted - 12/28/2015 :  10:22:45  Show Profile  Visit alevand's Homepage  Reply with Quote
I have it fixtured in place an ready to tack weld it. I can't plum the back wheel because the fairing is on .

... Progress today:



Too slurpee out for a test ride.

... Front brake hooked up, had to run a new cable.

C:
Tony Levand

Edited by - alevand on 12/28/2015 18:38:50
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PUGZCAT
recumbent enthusiast

Canada
466 Posts

Posted - 12/29/2015 :  06:24:33  Show Profile  Reply with Quote
I remember a while back a posting, may have been a kick starter invention, fork mounted spoke fairings for the top half of the wheel. The inventor made claims of drastically reduced drag. It might be worth the effort to try it out on the Carp as it could add a mph or 2 to the cruising speed. As a fail safe add tabs to the trailing edge to contact the rim side wall so the fairings don't become spoke shears with a strong side gust.
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alevand
human power expert

USA
3541 Posts

Posted - 12/29/2015 :  08:44:48  Show Profile  Visit alevand's Homepage  Reply with Quote
After plowing out the driveway I was able to test ride up and down the road. No obvious problems. Turning radius is noticeably larger. Ride is about the same. I am going to make a rudimentary nose before committing to the composite shape. I wonder if its better to have the nose rounded or more pointy and faired into the tire.

C:
Tony Levand
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Grant-53
recumbent guru

USA
554 Posts

Posted - 12/29/2015 :  09:14:57  Show Profile  Reply with Quote
I would suggest a nose radius 1/2 the wheel diameter and a circular cross section. See some sailplane profiles. I have seen the set up Pugzcat mentioned and I'll check Gizmag for a photo. If the nose is fork mounted be sure the area and cross Cd is greater behind the steering axis. A tight ball and socket fit to the main section would be good.
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alevand
human power expert

USA
3541 Posts

Posted - 12/29/2015 :  09:27:27  Show Profile  Visit alevand's Homepage  Reply with Quote
If its rounded , better in cross winds. If it's faired to the tire, then I would think better from no wind situations, as the flow is already disturbed at the stagnation point could be some separation (circulation bubble) due to the adverse pressure gradient on the rounded nose. I'll probably may part of it faired to the tire and the rest rounded with some treatment around the frame protrusion.

C:
Tony Levand

Edited by - alevand on 12/29/2015 09:38:47
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Grant-53
recumbent guru

USA
554 Posts

Posted - 12/29/2015 :  09:55:50  Show Profile  Reply with Quote
Always the compromise.

The Gizmag reference is from pg 28 April 24, 2014 for Upper Wheel Fairings by Garth Magee of Null Winds Technology.

Edited by - Grant-53 on 12/29/2015 11:19:02
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alevand
human power expert

USA
3541 Posts

Posted - 12/30/2015 :  07:29:36  Show Profile  Visit alevand's Homepage  Reply with Quote
I am piecing together a nose from coroplast. I need to fit in the last piece , then trim and fasten and duck tape. Have to clear another path out the driveway. A cat got caught ion the heating duct, tried to get it out 2 am last night. I may drive south of the snow line for a day ride. Looked at the IDOT expressway cameras for conditions. Springfield look clear this morning.

https://www.travelmidwest.com/lmiga/cameraReport.jsp?location=GATEWAY.IL.I-55
http://www.weatherstreet.com/weather-forecast/illinois-snow-cover.htm


... I hope the duct tape doesn't all peal off in the first rain...Hopefully the white paint will help seal it. Wood stove is putting out too much heat, have to wear a tee-shirt.


... Test ride up and down the road seemed OK. Lots of tie wrap tails clicking.... Hooked up bike computer and generator wires. Long wheel base is hard to make u-turns as I remember from the 2009 tour bike shown above, 90 inch wb. I haven't ridden it far enough to tell if its fast or slow yet.

C:
Tony Levand

Edited by - alevand on 12/30/2015 14:59:48
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alevand
human power expert

USA
3541 Posts

Posted - 12/31/2015 :  05:22:36  Show Profile  Visit alevand's Homepage  Reply with Quote
Test ride yesterday, was fine, no shoe rubbing. I did notice the tail edge had come unfastened, probably when the bike fell off the table and the microwave landed on top of it. I need to get the prop working. Id like to go for a ride, but I have commitments the next 3 days.

C:
Tony Levand
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alevand
human power expert

USA
3541 Posts

Posted - 01/01/2016 :  15:14:00  Show Profile  Visit alevand's Homepage  Reply with Quote
Rode yesterday and today, 25 miles each in 26 degree weather. I think I solve the cold toe issue, heated the shoes with the hot air gun and expanded the toe area, now I can wiggle them, not tight anymore. One of those Flevo tops would be nice to keep the wind off my cheeks. The fairing seem fine, though its hard to tell in the cold weather. Bike trial is snowed over, so no apple to apple testing. The longer wheel base makes for wide right turns.

C:
Tony Levand
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warren
human power expert

USA
6470 Posts

Posted - 01/01/2016 :  17:39:38  Show Profile  Visit warren's Homepage  Reply with Quote
How's the speed with the new fairing and the big wheel out front?
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alevand
human power expert

USA
3541 Posts

Posted - 01/01/2016 :  17:53:31  Show Profile  Visit alevand's Homepage  Reply with Quote
Its hard to say, I did 27 down the hill that I did 35 on, but it was 25F and a 10 mph head wind, air density is 8% higher vs 70F and a tail wind. It seems alright, the wheel base is too long, not enough steering correction for side gusts. I'll try making the arm on the fork shorter and try another test ride tomorrow afternoon, have to visit my mother in the morning. Less room inside and now have to contort to unzip the jacket. Tee shirt was sweated wet with only 2 shirts on. It doesn't look like nice weather any time soon. Ran through a pot hole was glad to have the big wheel. I had an idea to use a spoiler. Spoilers on a airplane are those doors that pop open just in front of the flaps once it's on the ground to kill the lift. Maybe it could be applied to the front of a streamliner to help control it in side winds.

C:
Tony Levand

Edited by - alevand on 01/02/2016 05:37:44
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alevand
human power expert

USA
3541 Posts

Posted - 01/02/2016 :  07:55:44  Show Profile  Visit alevand's Homepage  Reply with Quote
I moved the arm on the fork in 1/2 inch. I also moved it up and inch since the rod was hitting the tire on full left. I was hoping to get more, but now the rod it hitting the fork and gained only a few degrees. Test ride later...

C:
Tony Levand
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