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Speedbiker
human power expert

USA
3744 Posts

Posted - 11/21/2016 :  13:29:43  Show Profile  Reply with Quote
Jensen, I use Finishline Ceramic. I think it's pretty good.

Warren, I think you should do the side profile of the front of your trike to have the same profile as a P-51. I think that would work!
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warren
human power expert

USA
6089 Posts

Posted - 11/21/2016 :  15:00:05  Show Profile  Visit warren's Homepage  Reply with Quote
Snarly teeth?
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purplepeopledesign
recumbent guru

Canada
681 Posts

Posted - 11/21/2016 :  19:42:59  Show Profile  Reply with Quote
quote:
Originally posted by Jerry
Do you guys really use wax and oil?


Everyone has preferences. I expected that mention of WD-40 would be enough to lighten things up, but I see that my snark was just a little too subtle. Either that or everyone is just driving on the information superhighway a little too distracted this week.

:)ensen

Those who claim to be making history are often the same ones repeating it.

Video of my trike
http://www.youtube.com/watch?v=MdSLRD_2vzc
Photos of my trike
http://www.flickr.com/photos/purplepeople/
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Garrie L Hill
human power supergeek

USA
1691 Posts

Posted - 11/21/2016 :  19:55:06  Show Profile  Reply with Quote
https://youtu.be/fULNUr0rvEc

Garrie "carbon based lifeform" Hill
HPRA Co-Dictator of the East
for pics of some of my time and money sucking projects
http://s58.photobucket.com/albums/g277/cfbb/
and videos
http://vimeo.com/5513519


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purplepeopledesign
recumbent guru

Canada
681 Posts

Posted - 11/21/2016 :  20:52:43  Show Profile  Reply with Quote
Once again, the internet completely obliterates tone of voice and body language. Oh well, back to the regularly scheduled programming of DIY.

:)ensen.

Those who claim to be making history are often the same ones repeating it.

Video of my trike
http://www.youtube.com/watch?v=MdSLRD_2vzc
Photos of my trike
http://www.flickr.com/photos/purplepeople/
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Speedbiker
human power expert

USA
3744 Posts

Posted - 11/22/2016 :  02:23:46  Show Profile  Reply with Quote
Chicken fat! Ha ha ha!
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warren
human power expert

USA
6089 Posts

Posted - 12/02/2016 :  08:23:25  Show Profile  Visit warren's Homepage  Reply with Quote
I'm figuring out the steering in a rough sort of manner. This shows the remote steering linkage to the kingpin Ackerman lever. The remote steering linkage will reside in a slot cut into the frame.
These drawings are not to scale.



This bottom view shows the bell crank arm which links the long steer tube to the control arms. It should be the same length as the kingpin Ackerman lever.



This view from the front shows the internal bearing head tube and kingpin assembly. I will need to figure out the actual angle once I get all the parts together.



Bottom view of the kingpin, showing the Ackerman lever and drum brake mount.

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warren
human power expert

USA
6089 Posts

Posted - 12/03/2016 :  09:52:35  Show Profile  Visit warren's Homepage  Reply with Quote
Here's a cool racing trike that Tim Corbett of Australia built. It was designed to be faired, but there are many interesting aspects which would work on an unfaired trike as well.



It has an extremely laid back integrated seat, above seat steering, and the kingpins are mounted directly to the sides of the seat. This design is probably too laid back and narrow for an HPRA racer but would be great for longer tracks without tight turns.



The drive train runs through the chassis. In this photo you can see the steering bell crank.



He has built two versions of this trike, and still has the molds.



As you can see, the design is not optimized for use without a full fairing, but due to it's monocoque design it is likely no less aero than a traditional cruciform trike.



The trike is well faired underneath, which is an important area that is generally ignored by recumbent (and auto!) designers.



After seeing Tim's excellent design I will need to think more about my own design.
Moving the the front wheels back several inches to coincide with the front edge of the seat makes very good sense from a construction and strength standpoint. Now that I look, it seems that several trike designers have done this. While I can't recall reading anything about how tadpole front wheel location effects handling, intuitively I can see that pushing the front wheels back changes the weight distribution toward the front. Too far back and the the back wheel will slide too easily in hard cornering. Too far forward and the front wheels will "push" and loose traction in a corner. Neutral handling is best. Initially you would think that the front wheels would provide twice the traction of the rear wheel in a corner, but in a hard corner, most of the front weight is on the outside wheel. In reality, unless the trike is very off balance, you will start to tip over in a hard corner before reaching the traction limits of the front or rear tires. I think I will leave the front wheel location alone.

Tim's Steer tube is about 45 degrees as opposed to mine which was designed at 90 degrees. I think the 45 degree design is better as it negates the need for the tiller.

The belly pan is cool, and it fairs the rear wheel well. I need to think about total surface drag vs aerodynamics. Does it makes more sense to make the under seat area larger and enclose the drivetrain, or just make it smooth and aero and let the chain dangle?
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harv
recumbent enthusiast

386 Posts

Posted - 12/03/2016 :  12:47:54  Show Profile  Reply with Quote
It looks like the corner of the seat would coincide with the position of a cruciform on a standard trike. I think the molded seat has several inches of extra material at the end to fill out the space and is also a continuation of the belly fairing.
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PUGZCAT
recumbent enthusiast

Canada
459 Posts

Posted - 12/05/2016 :  08:19:34  Show Profile  Reply with Quote
The more weight that is on the front wheels the more resistant the trike will be to tipping over. Look at production models that have the same seating position that you want and take note where the front wheels are positioned in relation to the seat. A little shift in front wheel weighting can make a big difference, it's the reason tadpole trikes have adjustable bottom bracket booms and fixed seats, best not to reinvent the cereal bowl. Go big on the spindles, 20 mm thru axle hubs are complete with disc mounts.

Maybe go even more laid back on the seating like the current hour recumbent bike record holder, lie flat with shoulder stirrups and a little head rest. I like the seat tub design in the pics "frame rails" conforming to the body lines on either side, instead of seat over the frame. The design can be easily fully faired in case of Battle Mountain multi track record fever catching.
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aarntate
Starting Member

New Zealand
4 Posts

Posted - 12/05/2016 :  20:16:07  Show Profile  Reply with Quote
Trump Elite Chassis

[New-TX14-for-Pembroke-girls-1.jpg.webloc]
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aarntate
Starting Member

New Zealand
4 Posts

Posted - 12/05/2016 :  20:18:28  Show Profile  Reply with Quote
Try again.

Trump Elite Chassis


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warren
human power expert

USA
6089 Posts

Posted - 12/06/2016 :  16:02:26  Show Profile  Visit warren's Homepage  Reply with Quote
Looks fast! Wow that is laid back!

(I fixed your post to show the image)
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alevand
human power expert

USA
2909 Posts

Posted - 12/07/2016 :  05:10:52  Show Profile  Visit alevand's Homepage  Reply with Quote
What kind of crank set is that?

C:
Tony Levand
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Runxner
recumbent enthusiast

USA
441 Posts

Posted - 12/07/2016 :  07:10:20  Show Profile  Reply with Quote
Pink is the fastest color.

Team Low-Life
Lowracer Test Pilot/Evangelist
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PUGZCAT
recumbent enthusiast

Canada
459 Posts

Posted - 12/08/2016 :  17:45:29  Show Profile  Reply with Quote
That bottom bracket arrangement has the narrowest Q factor I've ever seen. Effectively the chain ring is sandwiched between sealed bearing cartridges like the wheel on a unicycle, clever! I'm thinking they build the crankset in house as it is intergrated into the design. It a wonder that no streamliner guru has thought of this before.
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Speedbiker
human power expert

USA
3744 Posts

Posted - 12/08/2016 :  19:49:51  Show Profile  Reply with Quote
Actually, my liner has a Q as narrow as that, or very near. I have 26mm between my crank arms. The chainring shares the same centerline as the right crank arm. What good does a centered chainring do if you rear cog is not on the same centerline?
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PUGZCAT
recumbent enthusiast

Canada
459 Posts

Posted - 12/09/2016 :  06:36:24  Show Profile  Reply with Quote
Misalignment isn't much of a factor if the chainline is over 6 feet long.
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Speedbiker
human power expert

USA
3744 Posts

Posted - 12/10/2016 :  05:33:56  Show Profile  Reply with Quote
That still doesn't justify the centered chainring, or make it right. Except that it looks cool. A lot of extra work for no design advantage I can see. But, what did I ever build that worked...?
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warren
human power expert

USA
6089 Posts

Posted - 12/10/2016 :  06:25:53  Show Profile  Visit warren's Homepage  Reply with Quote
Lower Q feet should be slightly more aero.
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Speedbiker
human power expert

USA
3744 Posts

Posted - 12/10/2016 :  07:29:07  Show Profile  Reply with Quote
Maybe, maybe not. But as we discussed, having a centered chainring is likely not the best way to do it. Their design looks complex and potentially structurally inferior, which no apparent advantage over a super narrow BB and custom crank. I would be surprised if the BB was as rigid as a full boom and chain line is affecfed. Especially in high gear. Seems hard to justify, but maybe they hsd their reasons.
I like that flat seat and shoulder brace, though.
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PUGZCAT
recumbent enthusiast

Canada
459 Posts

Posted - 12/10/2016 :  08:15:21  Show Profile  Reply with Quote
This trike is Pedal Prix equipment and race trim it's enclosed with a molded body so the narrow Q help keep the nose narrower. Check out youtube videos Pedal Prix seems to be very popular in Australia. It even draws good sized crowds. The basic trike must work pretty well or they wouldn't be able to sell them for $10000+.
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Speedbiker
human power expert

USA
3744 Posts

Posted - 12/10/2016 :  18:00:24  Show Profile  Reply with Quote
What does that have to do with the superiority of that centered chainring? Nothing! It works. From what I've seen from Ben and Gareth, their PPGP velo dominates, and neither it or their world record setting BM liners use that complex, centered chainring.
And what's your point? Do you think Warren should use it on his trike? That's what this thread is about. Maybe you will build a trike and use it. Tell us how it works for you. With Warren building this new trike and me coaching two guys to attempt trike speed records, I just might have to build a fast trike. Maybe PUG will show us how it's done and build one, too? Well?
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alevand
human power expert

USA
2909 Posts

Posted - 12/11/2016 :  05:09:10  Show Profile  Visit alevand's Homepage  Reply with Quote
The chain is centered, so the line of action coincides with the neutral axis of the boom. There would be more flex with a smaller chain wheel, due to higher chain tension, pulling a standard bb over to one side on the left pedal stroke. Vertical deflection would be the same. T Warren is not designing for a fairing, and for a velomobile, the crank length is more of an issue then width, if the wheels are faired in. I think there is more of an issue with the boom ending at the axle, it looks like the tie rods were added for stiffness.

C:
Tony Levand

Edited by - alevand on 12/11/2016 05:19:41
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Speedbiker
human power expert

USA
3744 Posts

Posted - 12/11/2016 :  06:32:46  Show Profile  Reply with Quote
Good job making all that up, Tony. Technically true, but do you really think it justifies all the problems it also creates? A classic case of over-engineering. "Let's design something that is heavier, structurally inferior, much more expensive and complex, and that is hard to service, all for a problem than hardly exists". Meanwhile they get beat at the races by a trike with a bolt on crank.
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