A narrower tire may cut through fresh powder better, but that's not the whole picture with winter driving. Consider hard packed snow, where no tire is cutting through anything. Or plain salt covered streets. Or ice. Or wet slushy junk. Aside from fresh powder, traction comes down to friction.I disagree but would consider your opinion if there were some quantitive analysis behind it.
Traction and handling are two different things, influenced by different characteristics of the tire. Handling is definitely affected by tire width, as well as sidewall height. Traction is not.in an controlled environment (a straight line and downhill I might add), all parts appear to be equal. however, in the real world were most of us drive our cars in different environments, wider and narrower tires do not have the same handling characteristics on the same car when driven by the same driver in the same conditions. i wonder what the good professor has to say about ice-skates having narrow blades, when people would surely be able to stand-up a lot easier with wider blades. he infers the friction coefficient would be identical with the ice-skates, and you imply they would perform exactly the same; they won't. same goes for skis, snowboards, and tires.
Not my professor, just a video I found that accurately demonstrates the simply physics principle. You keep referencing how the experiment was run "downhill." If it wasn't clear, it was so the same exact force was acting on both blocks. The downhill factor is irrelevant.For some, there is a fine line were traction ends and handling begins, but lets run with your story that narrower/wider tires make no difference. It has to do with how much rubber is touching the road, regardless of what your professor has taught us.
These cars weigh more than 2-tons and are moving, stopping, turning, and going in every direction most of that time that just straight downhill. But section width means nothing and is outdated? Sorry, I can't drink that Kool-Aid.
Let's leave handling out of this, because that has more to do with suspension than tires. I wasn't aware Indy or Nascar guys ran winter tires. Can you point me to a race run on snow? They run wide tires because the rubber compound is much softer. Softer = more friction. The tires are wide to distribute the heat. If they ran that rubber compound with 215mm tires, they would be lucky to last a few laps. If they could run narrower tires without giving up traction, they probably would because it would cut down a few pounds.I guess all the manufactures and vendors are giving out outdate advice; good to know. Those Indy car and Nascar guys have it all wrong too. Though one is likely just running a wider bald tire for handling, or is it traction?
O the sarcasm. No shit snow happens. How often are people (anywhere in the US) driving through fresh powder? I'm willing to bet it's a good mix of plain road, packed snow, and occasionally fresh snow. 205 vs 215 makes no difference, unless all you do is blaze trails all the time.Not everyone lives where you do and get to follow a plow truck or a snow compactor everywhere they go. Some actually have to drive in, well, snow. Maybe not in the summer months, but never the less, snow happens.
That's exactly it. Snow tires, in the US, are a hard sell to a lot of people. Manufacturers and vendors throw the cheapest option at people to lower the entry price point.BTW, narrower winter tires are cheaper than wider ones. Makes sense, outdated advice be damned, on a tire only used 4 months of the year. :naughty:
Don't confuse coefficient of friction and friction. Changing the downforce ABSOLUTELY changes the friction. It's a fundamental physics equation. Friction = friction coefficient x applied force. True, changing the area doesn't matter (assuming the force is constant)."Total friction," whatever that is, may not change. By definition, a coefficient is dimensionless and changing downforce or area does not change friction. Another way to say it is that the CoF is a fundamental property of the interface between the two materials,
Pressure does nothing to get a car moving. The car could weigh 30 tons, but if there is no friction between the ground and the tires, it won't go anywhere.Pressure, however, is quite another thing. Pressure is force per unit area. Increased pressure concentrates the force.
False, all around. Ice skates don't melt the ice. That's an outdated theory which was been discredited. http://www.ccmr.cornell.edu/education/ask/?quid=1138Ice skates do indeed work because of force concentration, which melts the ice and lowers the coefficient of friction (it's lower at the water-blade interface than the ice-blade interface.) It can get too cold to ice skate.
No, a narrower tire has the same contact patch. Please see the Road & Track link I previously posted.A narrower tire has a smaller contact patch, which means more downforce/unit area.
Yes, tire width is part of it, as well as tread depth and tread design. The snowshoe thing is a bad analogy. People depend quite a bit on friction for snow traction. Without it, they would be falling all over the place. Go strap a snowboard to each foot and see how far you get. The CoF does not change based on what you're driving on. It is solely determined by the rubber compound of the tire.That can displace water and/or snow - wider tires are more prone to hydroplaning, remember, because they lack the pressure to squeegee the water out of the contact patch. That's why snowshoes and wide tires keep people on top of snow - the downforce is more broadly distributed, but people don't depend on friction for traction on snow, and the CoF for a tire on powder is much lower than the CoF of a tire on packed powder.
False. I'll defer to the Road & Track link again.Every system is a compromise. In winter, the downforce at the contact patch matters more for going, stopping and turning, so smaller (narrower) is better. In summer, a larger contact patch means more tire to surface contact in all phases of dry road driving.
:headbash: Bobsled "runners" are long blades. They're a little thicker than an ice skating blade because they have to support more weight. They work off the same concept. The front runners (i.e. blades) rotate to steer the sled.Think of a bobsled. They have runners, not blades. The runners are highly polished for a low CoF and fast speeds. Yet they are wider than a blade to allow for some friction for turning.
(I apologize in advance for being crass here). The luge proves again you don't know what you're talking about. Please go read about it beforehand. The luge sled has two long blades, called runners. They are angled, and ride on an edge. This is closer to an ice skate than the bobsled. There is no fiberglass under the blades. The fiberglass is above the blades, for the rider to lay on. Yea, they steer by bending the runners. Rotational forces don't really come into play.The luge also proves the point as well. They have thin blades, to be sure, but the blades or steels are mounted on runners, typically fiberglass. The luger steers by applying pressure to the runners to bend them, and, perhaps more importantly, by SHIFTING the eight from one side to another, because in luge, steering is more about balancing rotational forces than about pointing the sled. When in balance, the highest speeds are attained.
Not sure what you mean by the 10/10ths comment. I assume tread depth, but not sure why that matters here.So maybe I'm a Kool-Aid drinker too, but narrower tires serve to maximize friction at the contact patch under winter conditions, and that's why they are better for starting, stopping, and turning in bad weather. Typically, no one drives his car at 10/10ths in winter conditions more than once.
believe it or not tons of people drive in fresh powder snow. say when they finish work or school or whatever the case is, and streets are unplowed. lots of major cities were on a budget and barely had enough snow trucks going around plowing and salting the streets. As a matter of fact i have always driven in streets with fresh powder snow, to get groceries, do some shopping, or whatever the case was. but i see what your saying. of course having a snow tire with factory width will be perfectly fine. but say a 16 inch tire will definately be better than an 18, 19, or 20 inch wheels with snow tires on em.I'm saying the whole "narrow is better for winter driving" advice everyone spews is overstated and overused.
It only applies for fresh powder which, for most, is a small percentage of their winter driving. There's nothing wrong with keeping stock widths to avoid giving up handling performance.
But you make a good point. Cheaper is better. The worst winter will be better than any all-season.