The Arithmetic of Hydroplaning a Bicycle ( per NASA )
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Ironically, you accidentally described how ice-skating works.
I'm sorry to say, but the level of technical knowledge on this forum is rather surprisingly low. Hopefully the knowledgeable people are just quiet.
edit: https://www.sciencedaily.com/release...1105104416.htm ( better article, same point )
I'm sorry to say, but the level of technical knowledge on this forum is rather surprisingly low. Hopefully the knowledgeable people are just quiet.
edit: https://www.sciencedaily.com/release...1105104416.htm ( better article, same point )
That's junior high level physical chemistry. I don't think you are in a great position to comment on the "level of technical knowledge on this forum," but would point out that no one is holding an AK-47 to your head and flipping the safety on and off to convince you to stay.
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That's junior high level physical chemistry. I don't think you are in a great position to comment on the "level of technical knowledge on this forum," but would point out that no one is holding an AK-47 to your head and flipping the safety on and off to convince you to stay.
That said, despite your claim that this is junior-high material, if you read the previous citation, you will find that important discoveries on this topic have been made as recently as 2019. I cannot speak for you, but I wasn't in junior-high that recently.
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#34
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Who the heck is riding a fat tire bicycle at 29.3 mph?
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Nearly lost it just the other day in soft, light gravel just about 2cm deep. WOW... What was that? Was I just Hydroplaning on gravel?
No... Its called "Ravelplaning"
https://www.roadbotics.com/2019/10/0...call-raveling/
Still... I don't know its math, but It was quite an uncomfortable experience to be sure...
No... Its called "Ravelplaning"
https://www.roadbotics.com/2019/10/0...call-raveling/
Still... I don't know its math, but It was quite an uncomfortable experience to be sure...
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No matter where you're at... There you are... Δf:=f(1/2)-f(-1/2)
No matter where you're at... There you are... Δf:=f(1/2)-f(-1/2)
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#37
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I note with interest how fast and furious ad hominem attacks appear here, and yet, how few comments discuss the fact that NASA's investigation finds bicycle hydroplaning to be completely possible. I wonder why...
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Come on. Grow up. And that goes for most of you commenting lately. If you are all emotionally hurt that you cannot refute NASA's investigation described above, I'm sorry for you. But 'tis better to remain quiet and be thought a fool, than to speak and remove all doubt.
If y'all want to turn this thread into a non-stop ad hominem attack, go right ahead. I won't acknowledge any more of that behavior, and it just illustrates that my proof above is beyond question. On the other hand, if you want to discuss bicycle mechanics, give that a try.
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So you don't find "I don't need no stinkin NASA arithmetic to tell me hydroplaning on a bicycle is moot. Ain't happening." to be a stupid remark? Maybe it was in jest, but that was exactly my point -- they needed to dial it down in order to generate a response.
I note with interest how fast and furious ad hominem attacks appear here, and yet, how few comments discuss the fact that NASA's investigation finds bicycle hydroplaning to be completely possible. I wonder why...
I note with interest how fast and furious ad hominem attacks appear here, and yet, how few comments discuss the fact that NASA's investigation finds bicycle hydroplaning to be completely possible. I wonder why...
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It isn't a "mathematical proof." That is pure ignorance on your part. It is merely a testable hypothesis, formulated in terms of a simplistic, ad hoc equation.
It can easily be tested, and either corroborated or refuted.
All of the evidence that I am aware of leads to the latter.
You berate everyone for their failure to mis-understand what that 1963 paper presents in that way that you have. The comical aspect of this, as well as your bizarre tirades and ranting and raving is that you seem equally and inexorably convinced it makes you look somewhat intelligent, whereas it actually starkly reveals you to be a complete and total buffoon.
It can easily be tested, and either corroborated or refuted.
All of the evidence that I am aware of leads to the latter.
You berate everyone for their failure to mis-understand what that 1963 paper presents in that way that you have. The comical aspect of this, as well as your bizarre tirades and ranting and raving is that you seem equally and inexorably convinced it makes you look somewhat intelligent, whereas it actually starkly reveals you to be a complete and total buffoon.
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Lets use your formula, a 25c tire, common to a race bike, at 100psi which is a common race pressure would mean that a bicycle would have to be moving 100mph in order to hydroplane, please show me the pro rider on a pro tour bike that achieves that speed in the dry, they don't because at a certain point its no longer possible for the bike to safely stay upright. It is possible, as your video shows, when the bike has been designed with fairings and more and I doubt you'll find one of those nut balls with the solid brass pair willing to try in the rain. Further, the formula you bring up is a generic one that doesn't take into account things like tire shape and tread pattern, its why tires like goodyear's aquatread and other brands' equivalents can change that equation and perform at higher speeds than a standard tire, by being able to direct the excess water through channels and away from the center section of the tire it increases the speed at any given pressure that a tire will hydroplane. Likewise, the narrow shape of a bicycle tire isn't accounted for in that equation because of its ability to cut through the water, bicycle tires don't need a specially designed tread to move water away, they're narrow enough to do it naturally. As to what speed the hypothetical nut job would need to be at to hydroplane their 25c tire at 100psi is an unknown because while anything is hypothetically possible, the reality is that it really isn't.
Even using a motorcycle tire as a comparison doesn't work, motorcycle tires are inches wider than a fat bike tire, and as a result the fat bike would need to hit higher speeds at equivalent pressure to hydroplane. Dropping the pressure to 36psi in a 25c tire to get it down to a reasonable 60mph also isn't a solution, while it would mean the tire can do it at 60mph using the formula and not the real world scenario of actual tire shape, getting a bike and rider up to 60mph on a tire that will pinch flat at 10mph just isn't going to work. So yes, you've proved everyone wrong, hypothetically you could, in some ridiculous long shot manage to hydroplane a bike. In the real world, its just a stupid argument to even try to stand behind. But have fun with it.
Even using a motorcycle tire as a comparison doesn't work, motorcycle tires are inches wider than a fat bike tire, and as a result the fat bike would need to hit higher speeds at equivalent pressure to hydroplane. Dropping the pressure to 36psi in a 25c tire to get it down to a reasonable 60mph also isn't a solution, while it would mean the tire can do it at 60mph using the formula and not the real world scenario of actual tire shape, getting a bike and rider up to 60mph on a tire that will pinch flat at 10mph just isn't going to work. So yes, you've proved everyone wrong, hypothetically you could, in some ridiculous long shot manage to hydroplane a bike. In the real world, its just a stupid argument to even try to stand behind. But have fun with it.
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I try to avoid riding in the rain, but.... Figure 38mm slicks at 40 psi, 210# rider and bike. At what speed would hydroplaning occur, if it did. Thanks.
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Perhaps our new contributor can weigh in on the assertion that heavier bikes guarantee a better workout than lighter bikes.
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Ironically, you accidentally described how ice-skating works.
I'm sorry to say, but the level of technical knowledge on this forum is rather surprisingly low. Hopefully the knowledgeable people are just quiet.
edit: https://www.sciencedaily.com/release...1105104416.htm ( better article, same point )
I'm sorry to say, but the level of technical knowledge on this forum is rather surprisingly low. Hopefully the knowledgeable people are just quiet.
edit: https://www.sciencedaily.com/release...1105104416.htm ( better article, same point )
First off, it's nothing close to 2 feet wide, and second, you can see it flopping around like a soft fender, and third, the front tire is unaffected by it anyway, and fourth, and most importantly, the results achieved by Martin comport with the investigations by both NASA and the NHTSA.
The pegs are only slightly narrower than the grips on the handle bar and the grips are typically 5.75” or 11.5” total. The hydroplane is about the width of the pegs as see in the video or roughly 20” which is close enough to 2 feet to be “about”.
Second, in the run up to the water and in the water itself, there is no visible “flopping” of the hydroplane. The hydroplane in this picture looks extremely rigid with bracing added to keep it rigid.
Third, the motorcycle dives into the water when the front wheel drops too deep and turns the hydrofoil in wing which pulls the motorcycle into the water. The wheel is getting much more assist from the hydroplaning of the hydrofoil than the wheel is hydroplaning.
Fourth, if you put hydrofoil on a motorcycle and hurl it across a body of water, of course it is going to “hydroplane” but it hydroplanes on the hydrofoil and not on the tires. Here’s the full quote from the Solid Works article says
The equilibrium of speed and balance would prove crucial in the completion of the task especially with no lateral stability, thus a ski–like hydro blade was fashioned on SOLIDWORKS to sit beneath the rear wheel to act as a hull in order to steady the bike whilst moving at pace.
Because, as I explained, the applicable constant has declined in the sixty years hence.
To be clear, are you admitting now that they are hydroplaning, or are you still delusional?
The question at hand, friend, was not "Is it possible to hydroplane during a time trial?" It is "Is it possible to hydroplane?" And people do ride with 30 psi in their tires.
Still an achievable speed when descending, or motor-pacing, or on an aero bike -- although very ballsy. Regardless, again, the question is not "Is it possible to hydroplane while riding the way I ride?" It is "Is it possible to hydroplane?"
Why is it odd? Brown used the same reference material, just older, less-accurate versions.
I have provided investigations by NASA and the NHTSA, both of which confirm that bicycles can achieve total hydroplane. I have provided video evidence of that phenomenon occurring.
If that isn't sufficient for you to understand, I daresay nothing ever could be.
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Last edited by cyccommute; 06-19-23 at 08:40 AM.
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"...further substantiated the fact that hydroplaning can create a very serious slipperiness problem to most pneumatic-tired vehicles."
Copied and pasted out of the NASA study. If one were to read the study, one would see references to "partial hydroplaning."
Having had one hydroplaning experience on a bicycle in some 60 years of cycling I don't really care whether or not it was complete hydroplaning or partial, it was most unnerving. Although the NASA study is most definitely way over my head, I do not believe that anywhere in that study is it proved that it is impossible to hydroplane on a bicycle and my personal experience is enough to convince me that even if the paper does say it is impossible (and it doesn't), then the paper is wrong. I was descending a mountain pass in the rain on a self supported tour on a tandem. The descent was straight, the stoker was still and the bike was behaving in ways I have never experienced before or since (thankfully). I have no idea how fast we were going but we were probably on 1.25" Schwinn Le Tours maybe pumped to 85 psi if someone wants to calculate anything. Total weight had to be over 300 pounds. Tell me I am wrong, tell me TC1 is wrong, I don't care. I don't believe that regardless. Be thankful it may be rarer than rare. Be thankful to not have experienced it but be hesitant to categorically dismiss it because someone told you NASA said so. I don't think they did.
Copied and pasted out of the NASA study. If one were to read the study, one would see references to "partial hydroplaning."
Having had one hydroplaning experience on a bicycle in some 60 years of cycling I don't really care whether or not it was complete hydroplaning or partial, it was most unnerving. Although the NASA study is most definitely way over my head, I do not believe that anywhere in that study is it proved that it is impossible to hydroplane on a bicycle and my personal experience is enough to convince me that even if the paper does say it is impossible (and it doesn't), then the paper is wrong. I was descending a mountain pass in the rain on a self supported tour on a tandem. The descent was straight, the stoker was still and the bike was behaving in ways I have never experienced before or since (thankfully). I have no idea how fast we were going but we were probably on 1.25" Schwinn Le Tours maybe pumped to 85 psi if someone wants to calculate anything. Total weight had to be over 300 pounds. Tell me I am wrong, tell me TC1 is wrong, I don't care. I don't believe that regardless. Be thankful it may be rarer than rare. Be thankful to not have experienced it but be hesitant to categorically dismiss it because someone told you NASA said so. I don't think they did.
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Let's see:
PSI-Hydroplane speed
5psi/23mph
10psi/33mph
15psi/40mph
20psi/46mph
30psi/57mph
40psi/65mph
50psi/73mph
60psi/80mph
90psi/98mph
120psi/113mph
CAN you hydroplane?
yes
Will YOU be hydroplaning?
HA! no.
PSI-Hydroplane speed
5psi/23mph
10psi/33mph
15psi/40mph
20psi/46mph
30psi/57mph
40psi/65mph
50psi/73mph
60psi/80mph
90psi/98mph
120psi/113mph
CAN you hydroplane?
yes
Will YOU be hydroplaning?
HA! no.
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Says the guy running 23s at 140psi.
Come on. Grow up. And that goes for most of you commenting lately. If you are all emotionally hurt that you cannot refute NASA's investigation described above, I'm sorry for you. But 'tis better to remain quiet and be thought a fool, than to speak and remove all doubt.
If y'all want to turn this thread into a non-stop ad hominem attack, go right ahead. I won't acknowledge any more of that behavior, and it just illustrates that my proof above is beyond question. On the other hand, if you want to discuss bicycle mechanics, give that a try.
Come on. Grow up. And that goes for most of you commenting lately. If you are all emotionally hurt that you cannot refute NASA's investigation described above, I'm sorry for you. But 'tis better to remain quiet and be thought a fool, than to speak and remove all doubt.
If y'all want to turn this thread into a non-stop ad hominem attack, go right ahead. I won't acknowledge any more of that behavior, and it just illustrates that my proof above is beyond question. On the other hand, if you want to discuss bicycle mechanics, give that a try.
Tell you what: go get a set of 23mm tires. Pump them up to 1.4 psi. At that pressure, according to the NASA formula, the bike should hydroplane at 12 mph. Now find a nice lake and go skim across it. Make sure that you film it because hilarity is going to ensue.
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Plan Epsilon Around Lake Michigan in the era of Covid
Old School…When It Wasn’t Ancient bikepacking
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
Stuart Black
Plan Epsilon Around Lake Michigan in the era of Covid
Old School…When It Wasn’t Ancient bikepacking
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
Last edited by cyccommute; 06-18-23 at 06:09 PM.
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