Schneegz

And the bikes kick ***... again. One bike is bone stock, the other is modified but still street legal. The final words of the article say it all.
Now, if I only had the skill to ride a bike that fast... :D

Superbike Magazine

Psylence

I used to race bikes

No matter how cool the car, it'll always be surpassed in coolness by the guy in the sportbike riding a powerwheelie in 5th gear!

Problem is... no one makes any interesting motorcycles anymore

zthang

Yea...bikes these days are ridiculously fast...but each still has its positives. Riding a bike is a lot more work than cruising in a car.

Schneegz

No joking. As much as I love my bike, the 6" of snow on the ground have kept me off it for days now :D

P00Man

bikes will always whip cars
________
LovelyWendie99

zthang

Only on the straights...

Jag

Wrong. Some sportscars can hold more corner speed than a sportbike but this is irrelevant since a bike can brake so much later and get out of the corner so much faster than a car. A stock sportbike will still smoke pretty much any street legal car around a race track. I have done some amateur car racing and I race bikes professionally so I think I can be fairly subjective on this although I'm far from being an authority, only stating my opinion based on experience.

zthang

You're probably right when it comes to average people, but I have a video on my computer from TopGear where they race a Carerra 4S against an R1, both stock with professional drivers around a track and the Carerra actually wins. The way they explained it is because the car has 4 wide tires and therefore more grip than the bike around the corners. The car did win there, but only by a hair. So i'm sure in real life situations, the bike would win hands down.

Jag

You might be right zthang, it really depends on the rider/driver. You're also comparing a $90k car to $8k bike though :D
Either could be faster I guess, it would just depnds on driver skills, road conditions and how twisty the road is.

Schneegz

Did you not read the mag article I posted? The cars were driven by a professional race car driver and included a Porsche GT3, which is a hell of a lot faster than a Carrera 4s. Despite that fact, all the cars, including the GT3, were beaten by a moto journalist on a bone-stock GSXR ON A ROAD COURSE.

The only car that beat Gixxer wasn't even street legal, and was in turn beaten by a modified, yet still street legal, GSXR that was ridden by a pro rider.

Remember; ALL THE CARS WERE DRIVEN BY A PRO RACE CAR DRIVER.

Ike

I have videos of the Walser Supra and a 260Z with a LT-1 against a couple different Busas and various sportbikes to support otherwise :p Overall it's a silly argument, I love bikes but we're comparing apples to oranges here.

Werth_lots

Can you post this Video?
Or a link to it?
Thanx a million

97gpGT

FYI- The area of contact means nothing at all when it comes to grip. The only thing that really matters as far as grip is concerned is the compound the tire is made out of.

Jag

What?? So that's why the tire's on a Formula 1 car are so wide?? Can I have some of whatever it is you're smokin' ?

The wider the tire the more grip you'll having on cornering and acceleration?
Bigger contact patch = More traction

zthang

Everybody's right here...its obviously a known fact that for the most part, bikes are much faster than cars...i know my dinky little $1500 CBR F3 will SMOKE my $30k Z any day of the week. :D

97gpGT

Looks like someone failed basic high school physics.... Next time you decide to make a semi-flaming post, make sure you know what you're spouting off about before you make yourself look like an ***.

The force of friction, which is what keeps your car on the road, is defined as f=N(mu_s), where N is the normal force acting on all four tires, equal to the mass of the car (m) multiplied by acceleration due to gravity (g) and where mu_s is the coefficient of static friction between the tire and the road. As you can see, the area of contact makes no difference to the frictional force that keeps your car on the ground. The work that this friciton does on the tires creates heat, and the heat will eventually build up until it's hot enough to melt the tire. When the tire melts, the rubber of the tire contacts liquid rubber, which contacts the road. This dramatically decreases the coefficient of friction, which decreases the fricitonal force and causes a person to lose traction.

If a rubber compound could be formulated that is completely heat resistant, the most efficient tires would be as thin and light as possible. Unfortunately, this has not happened yet and probably never will, so engineers decide to increase the amount of rubber which increases the amount of heat that the tires can absorb before they liquify. One kilogram of rubber can absorb only half the amount of heat that two kilograms of rubber can absorb before liquifying, which only absorbs two-thirds the amount of heat that three kilograms of rubber can absorb. The bigger, heavier, and more powerful a car is, the more force it exerts on its tires when it is cornering and accelerating and so its tires need to be more massive so that they can absorb the heat created by these maneuvers without liquifying and slipping when the driver hits the throttle or turns sharply. This is why a Lotus Elise, arguably the world's best handling car, can use much, much thinner tires (I believe the fronts are either 175 or 195, and the backs are somewhere in the low 200s) than a Viper or Porsche but still handle better. It's a light car that does not produce too much power, so its tires can be smaller and lighter without sacrificing driveability and without risking skids and spin outs when throwing it around a road course.

An F1 car uses such wide tires because it can pull multiple lateral g's when it's cornering. The massive amounts of downforce provided by it's aerodynamics increases the normal force that the tires feel, which increases the amount of frictional force that they experience. The greater frictional force means that more work is done on the tires by friction, so they heat up pretty quickly. The compound of these tires has a higher coefficient of static friction than normal tires if its temperature falls within a certain range. This is why you see F1 cars swerving back and forth before a start of a race. The drivers are causing friction to do a lot of work on their tires, heating them up to operating temperatures before they take off from the line. To make sure the tires don't exceed their operating temperatures, the techs and engineers of an F1 car equip it with large tires to better dissipate the heat created by its turning and accelerating during a race.

Jag

I only attempted to correct the previous post that tire width doesn't affect traction with a simple statement saying otherwise without getting into formulas and making myself look like a physics dork. Since you've resorted to name calling I guess I'll have to prove my point.

I didn't fail physics but it seems you're stuck in your grade 10 physics class as you've shown you can copy and paste a formula from an old text book. You're partially right in stating the basic friction formula as f=N(mu_s) and in that formula tire width doesn't enter the equation. The problem is this formula is much too basic to be used to determine tire traction, the key factor you're missing is how the coefficient of friction is calculated, when dealing with tires we cannot use a standard friction coefficient of 0.7 for dry pavement.

So, Do wider tires create more friction?

The answer seems simple enough. Surface area doesn't affect the total frictional force, as we've seen in the previously stated equation.

But this topic is much more complex than whether surface area affects friction. The wider tires used for some cars on the street are effective because there are more treads on a wider tire which cause more friction. In race cars, the width of the tire creates a lower rolling friction. The surface area is proportional to the traction from the stickiness of the tires when heated. The width of the tire does not directly affect friction, but along with other factors, such as the type of rubber, temperature, and tire pressure, tire width affects the coefficient of friction, which in turn affects the total frictional force.

Next time you decide to make a semi-flaming post, make sure you do some research before you make yourself look like an ***.