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Speedbiker
human power expert

USA
3749 Posts

Posted - 11/14/2016 :  09:06:15  Show Profile  Reply with Quote
Let's see it!
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warren
human power expert

USA
6093 Posts

Posted - 11/14/2016 :  15:27:28  Show Profile  Visit warren's Homepage  Reply with Quote
Here's the first conceptual trike drawing:

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carolina
recumbent guru

USA
571 Posts

Posted - 11/14/2016 :  16:28:52  Show Profile  Visit carolina's Homepage  Reply with Quote
Looks like true tank steer warren. I might like to try one (tank steer) someday. I always like this pic:

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velosRus.com
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Speedbiker
human power expert

USA
3749 Posts

Posted - 11/14/2016 :  16:52:38  Show Profile  Reply with Quote
Warren, why the forward sweep? Straight out with generous radii would be less turbulent, stronger, and easier to build.
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warren
human power expert

USA
6093 Posts

Posted - 11/14/2016 :  18:22:10  Show Profile  Visit warren's Homepage  Reply with Quote
I want to keep it as monolithic as possible, and move the start of the turbulent area as far back as possible.
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alevand
human power expert

USA
2915 Posts

Posted - 11/15/2016 :  03:46:53  Show Profile  Visit alevand's Homepage  Reply with Quote
quote:
Originally posted by warren

I want to keep it as monolithic as possible, and move the start of the turbulent area as far back as possible.



Yes, but the boom would be stiffer as a T, and these sections, I would imagine, would be streamlined, or act as splitters for your heels. The pan would extend farther forward, making more of a smooth under body.

C:
Tony Levand
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Speedbiker
human power expert

USA
3749 Posts

Posted - 11/15/2016 :  05:47:02  Show Profile  Reply with Quote
Also, congrats to Tony. For perhaps the first time ever on this forum he used the term "splitter" properly. A single plane separating a turbulent air mass, thus reducing it's size is a splitter.
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Patrick Bateman
New Member

USA
69 Posts

Posted - 11/15/2016 :  09:05:37  Show Profile  Visit Patrick Bateman's Homepage  Reply with Quote
quote:
Originally posted by warren

Yeah Thom, it would be carbon over foam. It's so easy to form the foam and it is remarkably stable. Adding the CF is admittedly a PITA, but the end result is very nice.

Tom, a fast Delta sounds cool, post some pictures when you can.

Here are my thoughts about design criteria for a racing trike

* 15 degree hardshell seat integrated with the frame for an aero underseat area.
* Overbuilt rear stays for good resistance to torsion in the corners
* RWD
* Lowest part has 2" ground clearance (probably an idler)
* Side stick steering
* Cruciform integrates with front of seat for aero
* Keep boom tube horizontal for as long as possible for aero

Does any body else have any good ideas I may be missing?






There's a carbon fiber windcheetah hypersport trike for sale over at BRO

Edited by - Patrick Bateman on 11/15/2016 09:10:00
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jjackstone
recumbent enthusiast

USA
231 Posts

Posted - 11/15/2016 :  11:46:04  Show Profile  Reply with Quote
Warren,
Have you checked out Carbontrikes? Integrated seat up to the cruciform. They do have an adjustable nonhorizontal boom though. Still a good representation of a smooth underside.



Website: http://www.carbontrikes.com/eng/models.html


JJ

Edited by - jjackstone on 11/15/2016 21:08:09
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warren
human power expert

USA
6093 Posts

Posted - 11/15/2016 :  13:21:58  Show Profile  Visit warren's Homepage  Reply with Quote
Good feedback guys, thanks. Yes, the boom stiffness would be an issue as it is quite long in the concept above. I'm concerned that if I just extend the seat pan up to the T shaped cruciform, air would be trapped between the pan and the rider. I'll re-draw it with a T-shaped cruciform.

Patrick- Looks nice but I don't think that the Windcheetah meets my criteria. I think that rear monostay would not be very stiff in hard cornering, underseat area is not clean aerodynamically, the steering is a yoke, etc.

JJ - That is very close to what I had envisioned, their steering system tends to mess up that smooth underside.

Here's Concept #2.

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rickmantoo
recumbent enthusiast

USA
274 Posts

Posted - 11/15/2016 :  18:52:00  Show Profile  Reply with Quote
Warren
It looks like the front wheels will hit your hands when you turn, maybe increase the wheelbase to give you a little more clearance. Otherwise looks good.

Rick
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Speedbiker
human power expert

USA
3749 Posts

Posted - 11/16/2016 :  07:02:48  Show Profile  Reply with Quote
Or put your hands above your crotch, like a lowracer. Also, make the leading edge of the cross beams pretty sharp.
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warren
human power expert

USA
6093 Posts

Posted - 11/16/2016 :  09:09:48  Show Profile  Visit warren's Homepage  Reply with Quote
Rick - I'll adjust the wheelbase and track width to prevent hand rub.
Thom - If I put a vertical frame extension just in front of the crotchal area, it would work well to brace the legs against while cornering. I would need to make it remote steering.
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harv
recumbent enthusiast

386 Posts

Posted - 11/18/2016 :  08:17:42  Show Profile  Reply with Quote
I'd think about the downside of having sharp edges cruciform tubes. I've had a few foot disengagements from my pedals and had the tube smack me in the calf. It was like being hit with a baseball bat. I'd worry about an aero beam being more like a machete.
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warren
human power expert

USA
6093 Posts

Posted - 11/19/2016 :  08:24:43  Show Profile  Visit warren's Homepage  Reply with Quote
Here, I cleaned up the hand drawn image in a paint program.



Total length - just shy of 8ft.

Harv - Yes I have had the foot suck experience too, and will definitely be using a normal aero section cruciform with a rounded front profile.

Edited by - warren on 11/19/2016 08:35:01
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Zephyr
Starting Member

USA
43 Posts

Posted - 11/19/2016 :  13:31:32  Show Profile  Reply with Quote
Looks great. Separating the under seat pulleys would give some clearance for the chains. Moving the return chain pulley forward might help. Curving the front edge of the seat upward a bit would help with the power chain and maybe help hold you in place under heavy braking. A larger diameter front chainring to match the 406" rear wheel would also help with the chain clearance at the front.

Dave

Edited by - Zephyr on 11/19/2016 14:23:51
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Speedbiker
human power expert

USA
3749 Posts

Posted - 11/19/2016 :  17:33:51  Show Profile  Reply with Quote
It looks great, Warren. I'm still hoping for gunners, but it's your trike. Seeing Zephyr's bike I don't know I'd listen to him on chain routing.
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warren
human power expert

USA
6093 Posts

Posted - 11/20/2016 :  09:30:32  Show Profile  Visit warren's Homepage  Reply with Quote
The trike has a huge butt cup to hold you in place but allow upper body movement. I'm not a 3D master so it's hard to see it in the drawing. In the drawing about the rider will practically be sitting on the idler. You can see the dotted line that represents the where the body sits inside the butt cup.

Thom, you needled me for the "gunner bars" version and I resisted but Dammit, I like it. All my other bikes have tiller bars so why not this too?



The tiller bar steering tube would need a linkage to the tie rod for steering. This will also strengthen the boom for better power transfer.


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Tom Schneider
recumbent enthusiast

112 Posts

Posted - 11/20/2016 :  10:58:48  Show Profile  Reply with Quote
Looks very good, Warren. I finally settled on gunners too, after looking at tank type (not aero enough), real L-R joy stick (aero, but could get too interesting in hard cornering).

Tom
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Speedbiker
human power expert

USA
3749 Posts

Posted - 11/20/2016 :  14:59:09  Show Profile  Reply with Quote
Warren, you are getting close to what I would have designed had I agreed to design a trike for the well known manufacture who asked me. I might have laid it back flatter, but I know that is right where you prefer it. Looks great. I would go with a single TC super idler ($$$) and a chain tube, just like we do on our NoComs.
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warren
human power expert

USA
6093 Posts

Posted - 11/20/2016 :  16:35:03  Show Profile  Visit warren's Homepage  Reply with Quote
Yep, all my RWD bikes use the biggest Terracycle idler.
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Larry Lem
human power expert

South Sandwich Islands
2524 Posts

Posted - 11/21/2016 :  08:56:20  Show Profile  Reply with Quote
I wonder how you could switch to big wheels all around. Little wheels are slow.

Larry Lem
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warren
human power expert

USA
6093 Posts

Posted - 11/21/2016 :  09:39:52  Show Profile  Visit warren's Homepage  Reply with Quote
We are not discussing religion, politics, or big vs small wheels in this thread!
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purplepeopledesign
recumbent guru

Canada
685 Posts

Posted - 11/21/2016 :  11:45:34  Show Profile  Reply with Quote
quote:
Originally posted by warren
We are not discussing religion, politics, or big vs small wheels in this thread!


Curious, what lube will you use on that TC idler? I currently use WD-40 but I also have a 23T coming from TC and would love to know what everyone else thinks is the best...

:)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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warren
human power expert

USA
6093 Posts

Posted - 11/21/2016 :  13:13:15  Show Profile  Visit warren's Homepage  Reply with Quote
Jensen! Next you will be asking to discuss the merits of chain wax vs chain oil.

Edited by - warren on 11/21/2016 13:15:20
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