tire direction
#76
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Joined: Jul 2015
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From: NW Oregon
Bikes: 1982 Trek 930R Custom, '91 Diamondback Ascent w/ XT, XTR updates, Fuji Team Pro CF road flyer, Specialized Sirrus Gravel Convert, '09 Comencal Meta 5.5 XC, '02 Marin MBX500, '84 Gitane Criterium bike
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.
Last edited by maddog34; 06-18-23 at 03:16 PM.
#77
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Joined: Dec 2015
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From: San Diego
Bikes: 1978 Bruce Gordon, 1977 Lippy, 199? Lippy tandem, Bike Friday NWT, 1982 Trek 720, 2012 Rivendell Atlantis, 1983 Bianchi Specialissima? 1998 Serotta Atlanta, 1981 Dave Moulton
You may be interested in the new thread, where that is discussed in more detail -- specifically the fact that NASA's equation proves bicycles can hydroplane.
#78
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From: Chicago area
Bikes: Airborne "Carpe Diem", Motobecane "Mirage", Trek 6000, Strida 2, Dahon "Helios XL", Dahon "Mu XL", Tern "Verge S11i"
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!
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!
#80
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Joined: Jul 2006
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From: San Jose (Willow Glen) Ca
Bikes: Kirk Custom JK Special, 86 De Rosa Pro, '84 Team Miyata,(dura ace old school) 80?? SR Semi-Pro 600 Arabesque
you can lose traction without causing a skid mark
and losing traction is not hydroplaning in all cases, much less hydroplaning on liquefied rubber
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Life is too short not to ride the best bike you have, as much as you can.
Life is too short not to ride the best bike you have, as much as you can.
#81
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Joined: Dec 2015
Posts: 916
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From: San Diego
Bikes: 1978 Bruce Gordon, 1977 Lippy, 199? Lippy tandem, Bike Friday NWT, 1982 Trek 720, 2012 Rivendell Atlantis, 1983 Bianchi Specialissima? 1998 Serotta Atlanta, 1981 Dave Moulton
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.
#82
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.
#83
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Joined: May 2021
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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).
#84
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From: Portland, OR
Bikes: (2) ti TiCycles, 2007 w/ triple and 2011 fixed, 1979 Peter Mooney, ~1983 Trek 420 now fixed and ~1973 Raleigh Carlton Competition gravel grinder
For now, I'll stick to Vittoria tires.
#85
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Joined: Oct 2014
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From: Portland, OR
Bikes: (2) ti TiCycles, 2007 w/ triple and 2011 fixed, 1979 Peter Mooney, ~1983 Trek 420 now fixed and ~1973 Raleigh Carlton Competition gravel grinder
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.
#86
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From: SF Bay Area, East bay
Bikes: Miyata 618 GT, Marinoni, Kestral 200, Soma double cross 2002 Trek 5200, KHS Flite, Koga Miyata, Schwinn Spitfire 5, Mondia Special, Univega Alpina, Miyata team Ti, Santa Cruz Highball, Waterford rs11
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.
#88
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Joined: Mar 2023
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From: Mascotte, Florida
yes I laughed out loud at that, just ride and see for yourself
#89
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From: NE oHIo
Bikes: Specialized, Trek, Diamondback, Schwinn, Peugeot
Amusing
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
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





