Wildguzzi.com
General Category => General Discussion => Topic started by: gearman on January 11, 2018, 09:03:00 AM
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Well I got the results on testing the dynamics of a reverse trike vs a standard one. The results are that all things being equal there was NO difference between the two. This was contrary to my gut feeling but agreed with the math. It was fun. The pictures show going 13mph real speed.Some kids came by and I took the picture.
(http://thumb.ibb.co/kP4o1m/IMG_0001.jpg) (http://ibb.co/kP4o1m)
(http://thumb.ibb.co/ixKhSR/IMG_0002.jpg) (http://ibb.co/ixKhSR)
(http://thumb.ibb.co/e0Hxu6/IMG_0005.jpg) (http://ibb.co/e0Hxu6)
free share picture (http://imgbb.com/)
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I don't buy into the"all things being equal" part because I don't believe that the dynamics of conventional trikes compare to reverse designs at that simplistic a level. Since nothing is offered in your report or test design to support your premise, I can't buy the conclusion. Perhaps if you explained it....
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show us the math..
(https://montieandme.files.wordpress.com/2009/08/08fe.jpg)
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:laugh:
Dusty
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The biggest problem with three wheeled vehicles with one front wheel is that during hard braking, weight shifts to the single wheel, so that even small steering changes can cause a crash.
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I don't buy into the"all things being equal" part because I don't believe that the dynamics of conventional trikes compare to reverse designs at that simplistic a level. Since nothing is offered in your report or test design to support your premise, I can't buy the conclusion. Perhaps if you explained it....
:1:
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I have ridden a snowmobile with a single ski and two treads. I have ridden a snowmobile with two skis and one tread. (Both for many miles when I lived where this was all we had in the winter, say 7 months each year.)
I have ridden a motorcycle with a single forward wheel and two rear wheels. I have ridden a motorcycle with two forward wheels and one at the rear. (I mention this second because I did more miles on the snowmobiles.)
My empirical research shows this limited evidence is (shall we say) tripe.
Unless someone can show me documented, measured, and peer-reviewable material, I maintain my view that a three-contact-point vehicle is inherently more stable when two of the three points are forward (direction of travel). I welcome evidence to the contrary from any disciplined, documented, and repeatable source.
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I did not see any test report.
If your test shows the one wheel in front is the same as two, then your test failed.
Where was the CG and how did you determine it for the test?
How did you simulate hard braking while cornering? (this is the one where I have twice seen people high sided from a trike with a single front wheel)
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Well,If you don't believe physical testing then I don't know what to say.What I wrote is only a small bit of what I did. I am satisfied.BTW I did not account for braking or acceleration.I agree turning while braking will change things.I am satisfied with my results and stand behind my testing.Any one in New Orleans can test my rig for your "peer review" :grin:
I believe the scientific method, and none of that has been documented here. If you did not account for acceleration (braking and turning are also acceleration since accel=change of speed or change of direction -- doesn't matter +/- or E/W) then you did not test the dynamics of the two configurations. Dynamics is the study of things that are not in equilibrium.
Gearman -- you're making a claim you say is based in science. Science is provable and repeatable. Show us the science. Show us the test. Show us the data. If there was any science involved, your peer reviewer wouldn't have to go to N.O. to repeat the test. Proper science is repeatable wherever the experimenter happens to be.
Bottom line for me is that I find your claim to be dubious, your methodology lacking, and your conclusions suspect. There is no verifiable or repeatable content to the report. In the absence of anything other than a blind assertion, I have to reject your findings.
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I guess you would not have believed Newton when he dropped the apple?
Newton certainly didn't expect to be taken at his word -- he showed his work in his book Philosophiae Naturalis Principia published ~1680 -- not gonna look it up for the precise date or spelling. He also stood for questioning on his claims and wrote many more pages explaining his experiments and calculations.
So if you're gonna invoke Newton . . .
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Newton didn't drop the apple. It dropped on him. :rolleyes: :rolleyes: :rolleyes:
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(https://pics.me.me/first-law-of-cartoon-physics-gravity-doesnt-work-until-you-3738488.png)
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Sir Issac probably had to write it out in long form with a quill pen and ink, typing-easy.
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Okay.....tell again, how come the trike?
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This has to be the only motorcycle site where I am reading Newtonian articles in response to my posts.There will be more to follow.I wish RK lived down here,we could really do some testing.I still stand by my first post,but it would be nice if I had a model with brakes and steering.Any rc guys here that could make a model?
Hang on a moment -- you're implying that I'm on board with this silliness and I am not. Especially in light of how this topic has progressed, I'll stand by my first post, also. The only reason I commented in this topic at all is because you insisted.
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For your results to have any validity, the tests you performed and the results you obtained must be quantifiable and reproducible by anyone, anytime, anywhere...that's the only way science works :cool:
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I know that and agree with that.I have been in the building and testing business for forty years.
If you know better than why this nonsense?
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A simple problem with so much testing and COMMENTS. For you gearheads, just do a simple "free body diagram" (this is a statics problem not a dynamics problem) and you will see as gearman was trying to prove, whether you ride a trike with 2 wheels in front or 1 wheel in front, that point where it rolls over because of centrifugal force, with all variables being the same, will be the same point. That being said: for you gearheads that want dynamics, weeeelllll!
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The biggest problem with three wheeled vehicles with one front wheel is that during hard braking, weight shifts to the single wheel, so that even small steering changes can cause a crash.
:1: Even my recollection of riding a pedal tricycle when I was kid clearly confirms this is the essential problem.
To ignore what happens under hard braking when doing one's testing is to test what doesn't matter much.
Moto
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No offense to anyone here and I'm not questioning any of the opinions stated but I have a question or 3. Aren't most reverse trikes set up with wider, car type tires all around as opposed to conventional trikes that have a motorcycle front wheel and 2 wider car type tires at the rear? So in the real world, wouldn't you be comparing apples to oranges, so to speak?
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Moto you are correct, but for each given set of variables to a dynamic problem, for 1 in front or 2 in front,(Mass, Acceleration, Deceleration, Time, Bumps in the road, Uphill, Downhill, heavy load on the back) the plotted chart would be all over the place. LOL
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Another aspect is the difference in steering authoritie . I've ridden Goldwing trikes, one wheel in front that were hard to get the beast to turn, especially trying to keep up on spirited rides on the back roads. If the corner has a little sand on it , forget it. So for that part, I think the two wheels in front would be better. Just guessing
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No offense to anyone here and I'm not questioning any of the opinions stated but I have a question or 3. Aren't most reverse trikes set up with wider, car type tires all around as opposed to conventional trikes that have a motorcycle front wheel and 2 wider car type tires at the rear? So in the real world, wouldn't you be comparing apples to oranges, so to speak?
Well, the reason for using a motorcycle tire when in the single front wheel configuration is to use a tire that makes turning easier - narrower, rounder, etc. I also simplifies suspension and steering design and lowers manufacturing costs. Unfortunately, in the real world this decision brings with it reduced braking capability (smaller tread patch), reduced grip when turning (same again), and a bunch of other undesirable characteristics.
So yes, we are comparing apples and oranges to some extent - but we're still talking about fruits and not vegetables.