tire direction
#51
Senior Member
Join Date: Apr 2016
Posts: 1,244
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 504 Post(s)
Liked 437 Times
in
336 Posts
Examine the pattern of the tread - if there's some directionality it will be in the form of chevrons, whether solid shapes or an arrangement of separate blocks or grooves. For smooth running on a paved surface you want the tip of the chevron to make contact before the sides, so the chevrons should be pointing forwards as you look at the tyre from above. This "might" also displace surface water to the sides. It is the direction for the rear tyre on dirt to dig in under traction, increasing its contact area. Reverse that for the front, so it digs in under braking. There is an argument for reversing those directions in soft sand because if the tyre digs in you'll just bury the wheel without gaining traction. IMHO YMMV
#52
Senior Member
Join Date: Jan 2009
Location: San Diego, CA
Posts: 3,677
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 839 Post(s)
Liked 1,064 Times
in
747 Posts
Your photo didn't link, and if I remember the rules, will not until you have 10 posts.
However, here's some help.
Most bike tires are not directional in any way. For those that are, the right direction depends on the intent. On a rear mtn bike tire the intent is to get the most push off in soft sand or mud, so mount the tire so the "harder" side of treads are to the rear on the bottom (forward on top). Reverse this in front so you get the maximum bite when braking.
For road bikes tread is mainly cosmetic, though it has some effect when the road is dusted with wind blown sand. Typical road treads often have herringbone type treads, modeled like those on car tires. The logic is that the point hits first and wedges water outward as the tire rolls. This doesn't matter on bikes, since water isn't an issue, but for cosmetic purposes mount so the herringbone points forward on top.
However, here's some help.
Most bike tires are not directional in any way. For those that are, the right direction depends on the intent. On a rear mtn bike tire the intent is to get the most push off in soft sand or mud, so mount the tire so the "harder" side of treads are to the rear on the bottom (forward on top). Reverse this in front so you get the maximum bite when braking.
For road bikes tread is mainly cosmetic, though it has some effect when the road is dusted with wind blown sand. Typical road treads often have herringbone type treads, modeled like those on car tires. The logic is that the point hits first and wedges water outward as the tire rolls. This doesn't matter on bikes, since water isn't an issue, but for cosmetic purposes mount so the herringbone points forward on top.
Likes For Crankycrank:
#53
Full Member
#54
I'm good to go!
Join Date: Jul 2017
Location: Mississippi
Posts: 15,002
Bikes: Tarmac Disc Comp Di2 - 2020
Mentioned: 51 Post(s)
Tagged: 0 Thread(s)
Quoted: 6199 Post(s)
Liked 4,816 Times
in
3,323 Posts
So if I ride too fast going around a corner on a dry road and my rear wheel goes out from under me, then I guess I must have hydroplaned!
Likes For sweeks:
Likes For sweeks:
#57
Full Member
No one here has offered any suggestion as to what that "something" might be, if it isn't hydroplaning.
Again, doesn't mean that the tire is completely riding on water. You've gotten nitpicky about the details, but hydroplaning has water substituting as road surface, yet even a loss of 25% of the traction of the tire still leaves 75% in contact, ie not hydroplaning, and still past the limit of the tire to hold.
Durometer does matter, because at your microscopic level some of the water is displaced allowing the softer rubbers to contact the pavement maintaining better grip but the wetter and faster things are the less that can be displaced reducing the level of actual grip. Road bikes don't hydroplane. I hit a puddle at 45mph, if my ass wasn't back I'd have gone over the handlebars because the tire cuts in and slows rapidly.
No one has yet offered any thing even resembling an explanation of how those videos -- not to mention a motorcycle travelling across a lake at bicycle speed -- are possible in this world that you imagine, where bicycles cannot hydroplane.
Until and unless someone, anyone, offers such an explanation, then I'm afraid you all are tilting at windmills. There exists video evidence of bicycles hydroplaning. That remains a very serious problem for all y'all who are claiming it cannot happen, and needs to be addressed.
#58
Senior Member
Join Date: Nov 2014
Location: Eugene, Oregon, USA
Posts: 27,547
Mentioned: 217 Post(s)
Tagged: 0 Thread(s)
Quoted: 18382 Post(s)
Liked 4,515 Times
in
3,355 Posts
With tractor tires, they say to mount with the chevrons pointing towards the ground in front so that the middle part contacts first. The theory is that it pushes the mud and water to the side to improve traction. Mounting them backwards pushes the mud to the middle and makes traction worse.
It should be similar for other types of tires, although perhaps to a lesser extent.
Likes For CliffordK:
#59
Full Member
And, again, we have video evidence of cycles hydroplaning -- which is the 800 pound gorilla in this particular room, who remains ignored.
I am still waiting for someone to explain how those bikes hydroplaned, if such is impossible. You have only three choices:
- Insist that all of those videos were doctored
- Explain the other as-yet-unknown phenomenon which caused the separation of tires and road, and which allowed that motorcycle to travel across a lake
- Admit the obvious, which is that bicycles can and do hydroplane
#60
Full Member
https://www.jensonusa.com/Schwalbe-R...ound-29-Tire-3
It is directional, but one would be hard-pressed to guess the proper direction by inspecting the tread pattern.
#61
Senior Member
Join Date: Dec 2019
Location: South Shore of Long Island
Posts: 2,801
Bikes: 2010 Carrera Volans, 2015 C-Dale Trail 2sl, 2017 Raleigh Rush Hour, 2017 Blue Proseccio, 1992 Giant Perigee, 80s Gitane Rallye Tandem
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 1088 Post(s)
Liked 1,028 Times
in
724 Posts
Because, as already explained, your vehicle's mass is fixed. And gravity is static. And the durometer of your tires is static ( within the constraints of one corner, anyway ). So something has to change, in order to prevent your tires from deforming into the surface -- otherwise they will continue to do so, due to gravity pulling them into the road surface.
No one here has offered any suggestion as to what that "something" might be, if it isn't hydroplaning.
No one here has offered any suggestion as to what that "something" might be, if it isn't hydroplaning.
Yes, exactly. If you go back and check that corner afterwards, you will find the black marks created by the liquid rubber on which you hydroplaned.
Yes, it is. Otherwise gravity would still be pulling down on your vehicle, and causing your tire to interface with the road surface, and developing traction. Gravity does not take holidays. It is always there.
Again, you are hydroplaning on liquid rubber. There is no other option, unless you turned off gravity.
Yes, it is. Otherwise gravity would still be pulling down on your vehicle, and causing your tire to interface with the road surface, and developing traction. Gravity does not take holidays. It is always there.
Again, you are hydroplaning on liquid rubber. There is no other option, unless you turned off gravity.
I most certainly did not refute my own argument. Cars do not "build tread", so restate whatever you were trying to write here, as this makes no sense.
I posted video of road bikes hydroplaning.
No one has yet offered any thing even resembling an explanation of how those videos -- not to mention a motorcycle travelling across a lake at bicycle speed -- are possible in this world that you imagine, where bicycles cannot hydroplane.
Until and unless someone, anyone, offers such an explanation, then I'm afraid you all are tilting at windmills. There exists video evidence of bicycles hydroplaning. That remains a very serious problem for all y'all who are claiming it cannot happen, and needs to be addressed.
No one has yet offered any thing even resembling an explanation of how those videos -- not to mention a motorcycle travelling across a lake at bicycle speed -- are possible in this world that you imagine, where bicycles cannot hydroplane.
Until and unless someone, anyone, offers such an explanation, then I'm afraid you all are tilting at windmills. There exists video evidence of bicycles hydroplaning. That remains a very serious problem for all y'all who are claiming it cannot happen, and needs to be addressed.
Likes For Russ Roth:
#62
Senior Member
Join Date: Apr 2016
Posts: 1,244
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 504 Post(s)
Liked 437 Times
in
336 Posts
There's no need for a "rule of thumb" when mounting tyres that have the intended direction of rotation marked on them, although you may want to try them the "wrong" way to address a particular requirement.
#63
Full Member
General note, I started a new thread with proof that bicycles can hydroplane. This will be my last reply here.
Again, for the hundredth time, please do not try and attribute this behavior to unnamed magical forces. What -- exactly -- is the "something" you believe in, to which you refer in that sentence? If you cannot name it, or explain it, I am inclined to quote Steve Wonder at you: "When you believe in things, that you don't understand, then you suffer."
Same thing.
They don't "build tread".
And motorcycles are many times heavier, resulting in similar tire psi on the ground.
For the hundredth time, how? Without a change in gravity or mass or pressure, how does this occur? Please do not attribute it to magic. I would like you to specify the physical phenomenon responsible for a tire ceasing to interface with the ground beneath it.
Are you kidding me? How is a motorcycle travelling across a lake not hydroplaning? I'm sorry, but I think you are completely divorced from reality.
Ibid.
They don't "build tread".
And motorcycles are many times heavier, resulting in similar tire psi on the ground.
Ibid.
#64
Senior Member
Join Date: May 2010
Location: Bastrop Texas
Posts: 4,490
Bikes: Univega, Peu P6, Peu PR-10, Ted Williams, Peu UO-8, Peu UO-18 Mixte, Peu Dolomites
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 970 Post(s)
Liked 1,632 Times
in
1,048 Posts
Tread usually
points in the direction of travel...
points in the direction of travel...
__________________
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)
#65
Full Member
#66
Droid on a mission
Join Date: May 2018
Location: Palm Coast, FL
Posts: 1,005
Bikes: Diamondback Wildwood Classic
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 317 Post(s)
Liked 280 Times
in
195 Posts
Move on, you have already beat this dead horse to oblivion
__________________
JoeTBM (The Bike Man) - I'm a black & white type of guy, the only gray in my life is the hair on my head
www.TheBikeMenOfFlaglerCounty.com
JoeTBM (The Bike Man) - I'm a black & white type of guy, the only gray in my life is the hair on my head
www.TheBikeMenOfFlaglerCounty.com
Likes For JoeTBM:
#67
Expired Member
Join Date: Jun 2007
Location: TN
Posts: 11,564
Mentioned: 41 Post(s)
Tagged: 0 Thread(s)
Quoted: 3683 Post(s)
Liked 5,448 Times
in
2,769 Posts
Apparently he can't help himself.
#68
Droid on a mission
Join Date: May 2018
Location: Palm Coast, FL
Posts: 1,005
Bikes: Diamondback Wildwood Classic
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 317 Post(s)
Liked 280 Times
in
195 Posts
I very rarely do this but I feel an "ignore" option coming on strongly.
__________________
JoeTBM (The Bike Man) - I'm a black & white type of guy, the only gray in my life is the hair on my head
www.TheBikeMenOfFlaglerCounty.com
JoeTBM (The Bike Man) - I'm a black & white type of guy, the only gray in my life is the hair on my head
www.TheBikeMenOfFlaglerCounty.com
#69
It's MY mountain
Join Date: Sep 2006
Location: Mt.Diablo
Posts: 10,002
Bikes: Klein, Merckx, Trek
Mentioned: 70 Post(s)
Tagged: 0 Thread(s)
Quoted: 4338 Post(s)
Liked 2,982 Times
in
1,618 Posts
Confirmed:
(later)
The physical phenomenon he's looking for is called "lubrication". He's essentially claiming that lubrication is the same thing as hydroplaning. While there are some similarities at a microscopic level, hydroplaning implies that the distance between the two surfaces is large enough that they don't even affect one another. An example would be a vehicle that enters a puddle that covers both paved road surface and a grassy shoulder. If the vehicle hydroplanes, it will pass over the pavement and over the grassy area with no difference in friction because it doesn't even sense the grass. If the vehicle doesn't hydroplane it will maintain contact with the pavement and slide with reduced friction to the grassy area where it will behave differently.
(later)
The physical phenomenon he's looking for is called "lubrication". He's essentially claiming that lubrication is the same thing as hydroplaning. While there are some similarities at a microscopic level, hydroplaning implies that the distance between the two surfaces is large enough that they don't even affect one another. An example would be a vehicle that enters a puddle that covers both paved road surface and a grassy shoulder. If the vehicle hydroplanes, it will pass over the pavement and over the grassy area with no difference in friction because it doesn't even sense the grass. If the vehicle doesn't hydroplane it will maintain contact with the pavement and slide with reduced friction to the grassy area where it will behave differently.
Likes For DiabloScott:
#70
Senior Member
Join Date: Jul 2015
Location: NW Oregon
Posts: 2,975
Bikes: !982 Trek 930R Custom, Diamondback ascent with SERIOUS updates, Fuji Team Pro CF and a '09 Comencal Meta 5.5
Mentioned: 15 Post(s)
Tagged: 1 Thread(s)
Quoted: 1299 Post(s)
Liked 739 Times
in
534 Posts
Well they don't of course. Auto tires are wide and have a flattish profile and they can hydroplane because the water can't out of the way fast enough. Bicycle tires could hydroplane if we're talking really wide ones like 4" with a flattish profile, but your basic road bike tire is too narrow and too round for that to happen; in fluid mechanics terms, the two do not have dynamic similarity so using one to model the other is invalid. The videos you posted show slippery roads and high resistance from riding through deep puddles, not hydroplaning.
More to the OP's point, no tread in any direction would've prevented any of those crashes.
More to the OP's point, no tread in any direction would've prevented any of those crashes.
do you also think bike brakes and automotive brakes aren't the same too?
Last edited by maddog34; 06-18-23 at 01:26 PM.
#71
It's MY mountain
Join Date: Sep 2006
Location: Mt.Diablo
Posts: 10,002
Bikes: Klein, Merckx, Trek
Mentioned: 70 Post(s)
Tagged: 0 Thread(s)
Quoted: 4338 Post(s)
Liked 2,982 Times
in
1,618 Posts
More strawman arguments
Likes For DiabloScott:
#72
SE Wis
Join Date: Apr 2005
Location: Milwaukee, WI
Posts: 10,517
Bikes: '68 Raleigh Sprite, '02 Raleigh C500, '84 Raleigh Gran Prix, '91 Trek 400, 2013 Novara Randonee, 1990 Trek 970
Mentioned: 40 Post(s)
Tagged: 0 Thread(s)
Quoted: 2747 Post(s)
Liked 3,401 Times
in
2,058 Posts
"One of the most commonly used equations for predicting hydroplaning was developed by NASA. This equation is also known as Horne’s hydroplaning equation [7] which is valid only for smooth tires with limited groove and tread design."
Horne is still in use today.
https://vtechworks.lib.vt.edu/bitstr...per_REVIEW.pdf
Horne is still in use today.
https://vtechworks.lib.vt.edu/bitstr...per_REVIEW.pdf
#73
Full Member
Grumpus and I were having a brief side chat about whether or not one can reliably determine intended tread direction by visual inspection of the pattern. That's not directly related to the main issue that I have been educating y'all on, hydroplaning.
If you were offended that I replied in that side conversation, well, get over yourself. Same applies to @shelbyfv.
And, for the record, the horse is still kicking, because several people here still cannot understand that bicycle tires can, and do, hydroplane -- despite proofs from NASA and NHTSA, and video evidence.
If you were offended that I replied in that side conversation, well, get over yourself. Same applies to @shelbyfv.
And, for the record, the horse is still kicking, because several people here still cannot understand that bicycle tires can, and do, hydroplane -- despite proofs from NASA and NHTSA, and video evidence.
#74
Full Member
#75
Full Member
Recommend that you do some reading about how thin "large enough" is, in this context. "Large enough" is still microscopic. You are getting closer to understanding the concept, though, which I commend -- unlike some of your compatriots here.