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Tom Schneider
recumbent enthusiast

112 Posts

Posted - 12/11/2016 :  09:21:59  Show Profile  Reply with Quote
The centered chain wheel changes the deflection from mostly to the right to equal in both directions, probably same watt loss.
Much easier to use a larger stiffer boom that may weigh slightly more.

Tom

Edited by - Tom Schneider on 12/11/2016 09:23:09
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Speedbiker
human power expert

USA
3744 Posts

Posted - 12/11/2016 :  13:08:11  Show Profile  Reply with Quote
Also, the torsional deflection Tony spoke incorrectly about is caused by the force of the pedal not being in line with the tensile resistance of the chain. The centered chainring could very well make this (insignificant)problem worse. None of which has anything to do with Warren's trike design. But feel free to continue digging up irrelevant pictures and making up your own physics, as usual.
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PUGZCAT
recumbent enthusiast

Canada
459 Posts

Posted - 12/11/2016 :  14:57:49  Show Profile  Reply with Quote
Bottom bracket bearing losses would likely be less for the center chain ring arrangement as the bearings are farther apart on the spindle, as opposed to inward facing bearing cups and very closely spaced cones on a spindle.

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Speedbiker
human power expert

USA
3744 Posts

Posted - 12/11/2016 :  15:38:06  Show Profile  Reply with Quote
Thanks for the irrelevant post. I would expect nothing less. The amount of load a human being can put on high grade bearings (cups, really?) is inconsequential. What did you build, again?
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alevand
human power expert

USA
2910 Posts

Posted - 12/11/2016 :  15:44:51  Show Profile  Visit alevand's Homepage  Reply with Quote
I like farther apart bearings, I loose one now and then....

C:
Tony Levand
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Runxner
recumbent enthusiast

USA
441 Posts

Posted - 12/11/2016 :  19:30:12  Show Profile  Reply with Quote
quote:
Originally posted by PUGZCAT

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+.


They're also required to have a dual side chain guard, another cm they saved or extra calf clearance
They can independently swap out crank sizes for different riders independent of chainrings..


Team Low-Life
Lowracer Test Pilot/Evangelist

Edited by - Runxner on 12/11/2016 19:30:53
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Speedbiker
human power expert

USA
3744 Posts

Posted - 12/11/2016 :  19:36:07  Show Profile  Reply with Quote
Tony, aren't you using high end cartridge bearings? I have never heard of anyone ever having a problem with those. We use two 10mm wide sealed bearings with about .10" between them, pressed in a precision turned shell and a Phil bb spindle. We've never had a problem, and the Cos has 16 years of racing on it. Design it right and it works. Period. What kind of setup could you "loose" a bearing from?
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Speedbiker
human power expert

USA
3744 Posts

Posted - 12/11/2016 :  19:37:45  Show Profile  Reply with Quote
The Q on that PPGP velo isn't remotely narrow.
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alevand
human power expert

USA
2910 Posts

Posted - 12/12/2016 :  03:25:40  Show Profile  Visit alevand's Homepage  Reply with Quote
No, I use cheap Chinese bearings from VXB. None of my stuff is precision, maybe I'll get a lathe someday. I had one fail, maybe 8000 miles on it. Could have been water in it. It was thinner than 10 mm, maybe 8 mm and shielded type. I replaced it with a thicker sealed bearing, 7/16 wide (11 mm) 99502H.

C:
Tony Levand

Edited by - alevand on 12/12/2016 03:26:57
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PUGZCAT
recumbent enthusiast

Canada
459 Posts

Posted - 12/12/2016 :  13:29:44  Show Profile  Reply with Quote
Well, back to trike design, KMX have self centering steering. The weight is at it's lowest point in the steering range when pointed straight. Something like a python center steered bike, but with proper trail instead of lots of lead. They're really nice handling trikes. King pins that are canted in at top and angled back.
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rickmantoo
recumbent enthusiast

USA
274 Posts

Posted - 12/14/2016 :  19:31:47  Show Profile  Reply with Quote
Warren
So Took the information you provided in these posts and the discussions we have had and drew up how I thing the trike could be built. My concept is to use a 4x8 sheet of 2" Styrofoam and cut slabs to make a frame 6 " thick The seat is carved down almost the entire 6 " depth and the boom is supported by a vertical piece of 2" thick foam. The 4" TC Idler is 3" off the ground. 15 degree king pin angle, 12 degree castor, 3-20" wheels.



Here is a drawing with the front wheel removed. The drawings are not 100% but should provide enough detail to get the concept across. Thrust rated rod ends are used to provide the supports for the kingpins.



Rick W
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Speedbiker
human power expert

USA
3744 Posts

Posted - 12/15/2016 :  00:32:48  Show Profile  Reply with Quote
Very nice, Rick. Not surprising from a real engineer and very experienced streamliner, sweet velomobile and leaning delta trike builder.
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rickmantoo
recumbent enthusiast

USA
274 Posts

Posted - 12/17/2016 :  10:16:42  Show Profile  Reply with Quote
Thanks Thom for the kind words. So I did some revisions to the drawing so one could sit even lower. Adding a 2" slab to the bottom and adding another idler location I was able to get the seat bottom to 4" off the ground. and added a 72 tooth chainring for additional gearing.


I also wanted to see what the wheel base would be if one used a 556 (26") rear wheel.



Now it is up to Warren to to decide if he wants to build a new trike or keep using one from the lending library.

Rick
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Speedbiker
human power expert

USA
3744 Posts

Posted - 12/17/2016 :  17:46:59  Show Profile  Reply with Quote
Nice work Rick. I don't think I would trade an inch lower seat for and extra idler. Also, it's hard to see in 2D, but it looks like excessive frontal area between the seat structure and steering knuckles/kingpins. Can your design a very close fitting butt bucket but have very slim wings reaching out to the kingpins? And can you reduce the frontal area of the steering knuckle assembly? Perhaps having the gap in the knuckle only wide enough for the spindle and steering arm, with close tolerance bushings in the pin and thrust washers above and below the spindle. I think you could get the whole assembly height down to less than an inch and a half. And as small or smaller arm reaching out to it.
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Tom Schneider
recumbent enthusiast

112 Posts

Posted - 12/18/2016 :  04:27:29  Show Profile  Reply with Quote
I think Warren has said 15 degrees seat angle was good for him, if I recall correctly. Can you change the seat angle?
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alevand
human power expert

USA
2910 Posts

Posted - 12/18/2016 :  05:50:29  Show Profile  Visit alevand's Homepage  Reply with Quote
He already has trouble seeing over his knees and feet, the seat would have to be raised up. I like the double idler. Maybe it could have removable panels to close up and smooth out the big open space for chain clearance through the rear stays.


quote:
Originally posted by Tom Schneider

I think Warren has said 15 degrees seat angle was good for him, if I recall correctly. Can you change the seat angle?



C:
Tony Levand

Edited by - alevand on 12/18/2016 06:01:38
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Johnsfwdbent
recumbent enthusiast

USA
116 Posts

Posted - 12/18/2016 :  13:35:28  Show Profile  Reply with Quote
Tony,
You shouldn't have to see over your knees or feet! You look between them.
If you needed to see over your knees I would be in trouble on all my recumbent bikes!

John
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Speedbiker
human power expert

USA
3744 Posts

Posted - 12/18/2016 :  17:53:37  Show Profile  Reply with Quote
Yup, just like every lowracer and streamliner I've had since the late 90s. You look between your knees and past whichever knee is down, and your brain puts it all together.
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warren
human power expert

USA
6090 Posts

Posted - 01/07/2017 :  10:18:59  Show Profile  Visit warren's Homepage  Reply with Quote
Rick Wianecki has been designing and building recumbent bikes and trikes since well before me, and was one of the original members of the WISIL HPVers. He's still involved in the HPV scene and is a strong believer in the composite over foam building method. When he saw what I was planning he volunteered to create the trike in CAD using a scale model of me to ensure that it was sized properly. We went back and forth several times to tweak the design and I think what we ended up with is extremely close to my latest design thoughts.




He then generated the templates needed to build a 1/4 scale model. Very cool! (See http://www.recumbents.com/wisil/trike/default.htm for the templates and more info about this project).

He then cut out the sections and built the 1/4 scale model trike, using 1/2" insulation polystyrene foam.




Rick even made scale kingpins, dropouts, and a scale idler under the seat to allow us to ensure that the design will work before building the full scale foam core.



The major change between my last drawing above and this model is incorporating the cruciform into the leading edge of the seat. The trike will have cruciform stubs sticking out wider than the seat because this bike will need to go fast around the corners.


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Speedbiker
human power expert

USA
3744 Posts

Posted - 01/07/2017 :  14:20:34  Show Profile  Reply with Quote
Looks great. I've always liked Rick's scale models. I have one around here somewhere.
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xrs2
Starting Member

USA
21 Posts

Posted - 01/13/2017 :  14:28:35  Show Profile  Visit xrs2's Homepage  Reply with Quote
This looks like an awesome project. Can I have one?

Question: What would be the major advantage over something like a Windcheetah FRO? My understanding is that you can ask to drop the seat to be almost on top of the wheel or DIY. That's what I'm considering because I don't have your skills.

www.ridingthecatskills.com
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warren
human power expert

USA
6090 Posts

Posted - 01/14/2017 :  10:01:15  Show Profile  Visit warren's Homepage  Reply with Quote
The major improvement over the Windcheetah is aerodynamics. Can you have one? LOL. Yes (in my best Dr. Evil voice) It will cost one million dollars! Seriously though, I'm planning on building one for myself, but I'm sure Rick would approve making the plans available once they are finalized for those who wish to build their own. For one million dollars.

More tweaking. Moved the BB as low as possible to bring it closer the "The Position". It's now about 8" above the seat pan.



Warren
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ShelGame
recumbent enthusiast

USA
254 Posts

Posted - 01/14/2017 :  10:27:03  Show Profile  Reply with Quote
Looking forward to seeing it in person at Waterford Hills :)
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xrs2
Starting Member

USA
21 Posts

Posted - 01/14/2017 :  11:53:47  Show Profile  Visit xrs2's Homepage  Reply with Quote
Ah but the problem is that I have neither the skills nor the space for a project like that! How about I trade you my incredibly useful medical writing skills for a trike. Or I can just provide you with an abundance of admiration. And who doesn't need that? :-)

Seriously, though, I think with a lot of optimization (which is actually within my minimal skill set) I might be able to come close but of course it won't be nearly as cool.

www.ridingthecatskills.com
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rickmantoo
recumbent enthusiast

USA
274 Posts

Posted - 03/26/2017 :  11:05:00  Show Profile  Reply with Quote
OK so Maybe Warren should consider building a Big Wheel version of this trike, using 559, 650 0r 700c wheels.

Something like this:



Rick W


Edited by - rickmantoo on 03/26/2017 11:25:39
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