maddog34

look up "friction" next... you'll possibly realize that tire contact and brakes converting motion into heat are the SAME basic principle.
and a skid is just a reverse burnout... both melt rubber into little tiny balls.. AKA: "the marbles". created by heat as a result of FRICTION... you know... the same thing that makes brakes work.
enjoy eating your straw.

oh, and sliding tires across oily pavement is really... are ya sittin' down?.... petro-planing.

now... what makes wet pavement slippery when compared to dry pavement?
a thin layer of water... we know that as HYDROPLANING.... the amount of hydroplaning occurring is all that stands between you and that guardrail on the outside of any corner when the road surface is wet... speed reduces the time that the water has to get out from in between your tires and the pavement's surface.. tread helps speed the removal... directional treads actually create a pumping action as well as channels to facilitate the evacuation of the offending liquid.

L134 

I suspect many of the people who cite the NASA paper have not actually read the paper. Having actually experienced what I thought was hydroplaning while on a bicycle, I was skeptical of the claims that it is impossible per the NASA study so decided to actually read the study to see if it in fact said this. Most of it was completely over my head but I did note something called partial hydroplaning in the study. OK, so if one wants to split hairs, maybe I was not technically experiencing 100% hydroplaning but maybe it was partial hydroplaning. In any event, it was VERY unnerving. It was a one time event on a fully loaded tandem descending a mountain pass in Canada in the rain. The bike was moving in ways I have never experienced before or since. I yelled at my wife to sit still. She responded that she was. So, no matter what anyone more knowledgeable might say here, I am convinced that I have experienced at least partial hydroplaning that one time, would prefer it never happens again, and believe that the cited NASA paper does NOT prove me wrong. I might add the paper does also mention the liquefying of tire. Anyway, sometimes reality trumps study/theory. In reality, science is just theory. If one wants to claim that it is impossible that I was hydroplaning then I would be curious as to what your theory is on what I was experiencing. Maybe I was just hallucinating?

sweeks

Well, it's a lot more than that. Science is the best way we have to understand the natural world. It's not perfect, being a human endeavor, but it's self-correcting and, given enough time, leads to better understanding.
In science, the word "theory" means a concept that is so well-supported by evidence that it's generally accepted as "truth"... at least in the scientific community. A theory starts as a "hypothesis", which may be not much more than an observation or educated guess. Then the hypothesis is tested, attempting to show that it's wrong; in other words to "falsify" it. If this happens, the scientist goes back to the drawing board and generates another hypothesis. When the hypothesis has been tested enough by multiple investigators, and becomes useful for making predictions, it attains the status of a theory.
Examples of theories include Germ Theory of Disease, Evolution, Continental Drift. These have stood the test of time and many challenges, but they *could* be falsified... whoever did this would instantly win the Nobel Prize!

shelbyfv

L134, that does sound frightening regardless of the cause! How did you correct it?

squirtdad

Of all the silliness you have posted this seems to be the most ridiculous.
you can lose traction without causing a skid mark

and losing traction is not hydroplaning in all cases, much less hydroplaning on liquefied rubber

L134 

Long time ago, 1982. What I do recall is that I was terrified, I sensed that I had pretty much no control of the bike (probably not true as we did not crash) and I NEVER told my now ex-wife. I think I probably just managed to gradually slow down, stop, and take a deep breath. BTW, it was not a shimmy. It was more like a floating sensation. This topic has always fascinated me because of the experience and I simply don't buy the argument/theory that it is impossible to hydroplane on a bike, regardless of what any scientist might tell me.. I will also contend that the cited NASA study actually does NOT prove it impossible and therefore I am NOT dissing the scientists and am NOT denying the science.

Trakhak

I've had exactly the same experience, although in my case it was on a fine layer of sand. Probably not hydroplaning in your case or mine.

jolly_codger

Well all I know is that there should be a law standardizing the location of the arrow on the sidewalk. Forget all this hydroplaning stuff, let's talk about all the time wasted worldwide looking for the gosh darn arrow (especially for those of us needing reading glasses).

79pmooney

Continental Drift! Right on topic. So those tires have been studied in detail by the non-cycling world. Is the drift more in wet conditions? Did they measure water thickness? Can you extrapolate the results to other tires? And did they study this drift at speeds relevant to cyclists? (The experience of the tandem rider a couple of post up sure sounds like it could be described as "drift". Were those tires Continentals?)

For now, I'll stick to Vittoria tires.

79pmooney

And my other wisecrack comment - I make it a point of seeing to it my tires always rotate so that the tread on top goes forward. I find the bike very difficult to balance when they rotate backwards and even when I can do the balancing act, I go not arrive where I intended to go.

curbtender

You guys talking about losing your grip? The only time I've had issues on asphalt being wet is when it was painted and on tarred cracks.

ElClemente

yes we can see it all on you tube and hear it on the web

ElClemente

yes I laughed out loud at that, just ride and see for yourself

speedy25

All this chatter and I didnt see much about tire direction.

If you look directly at the tread and see a caret ^ or arrow head in the tread it is directional. When looking at the tire from the back or front the "point" should be facing up. If there is a directional arrow, that will match what I just wrote. It will be the opposite for the front.

HOWEVER many of the better quality tires will have a two sided arrow on the sidewall which will have front and back marked on either side of the arrow. This DOES match what I have described. Another conventional marking is POWER with an arrow that will also match.
The power scenario matches why the tire is mounted rotating one way for the rear and the opposite for the front. Rear has forces transmitted from the chain. Front has the most force from braking.

Got it figured out now?

-SP