Sportbikes are not beginner bikes

[ceo012384]

Originally Posted by Mistress Maygin

It wasn't the height so much as the width of it. I have to spread my legs further to fit

Funny, I've had so many girls say this to me.

Originally Posted by NeonspeedRT

Ummm, have you ever taken an MSF class? Have you ever done any reading on Motorcycle basics or physics? If not, I encourage you to do both asap. When cornering on a motorcycle traction is reduced. Depending on the amount of lean angle, you have a smaller contact patch on the road. Have you ever watched any motorcycle racing? When they are leaned over in a corner, they are using maybe a fraction of the tires contact patch.

In a car, you have more contact path because the tires are turned. You don't turn on a motorcycle. You countersteer. A motorcycle turns nothing like a car.

Please do some research before you start giving people the wrong information.

Man, if you're going to speak in such a haughty fashion, you should at least be right. You're not. This post is ridden with inaccuracies.

Have YOU done any reading on motorcycle physics?

- The contact patch doesn't get much smaller when the bike is leaned over with the profile of today's tires... the traction is not decreased.

- Contact patch size depends on tire profile, lean angle, and how hard you are on the gas. And with today's tire profiles, at full lean there is still a very large contact patch.

- The reason turns are a problem is because the centripetal forces of cornering are trying to 'shear' the tire. When accelerating in a straight line, the forces of acceleration as well as gravity squat the tire onto the ground and there is TONS of friction. When in a turn you just have gravity and a very slight acceleration, and then the cornering forces are ripping at the tire in a sideways fashion. I.e. in layman's terms, you're close to sliding. Think about it, if a carboard box were coming toward you on the ground, would it be easier to stop it by pushing against it, or by moving out of the way and pushing against the side of the box to try to stop is via friction between your hands and the surface?

- In racing, how are they only using a 'portion of the contact patch'? The contact patch is the portion of the tire in contact with the ground. They're using 100% of it. This is true for normal riding too, not just racing.

- In a car, you don't have more contact patch because the tires are turned. You have more contact patch because the tires are wider and they are flat, and the cornering forces act to load those tires far more in the vertical direction than with a motorcycle, yielding large rectangular contact patches.

Hope this clears things up.

[NeonspeedRT]

Originally Posted by ceo012384

Man, if you're going to speak in such a haughty fashion, you should at least be right. You're not. This post is ridden with inaccuracies.

Have YOU done any reading on motorcycle physics?

- The contact patch doesn't get much smaller when the bike is leaned over with the profile of today's tires... the traction is not decreased.

- Contact patch size depends on tire profile, lean angle, and how hard you are on the gas. And with today's tire profiles, at full lean there is still a very large contact patch.

- In racing, how are they only using a 'portion of the contact patch'? The contact patch is the portion of the tire in contact with the ground. They're using 100% of it. This is true for normal riding too, not just racing.

- In a car, you don't have more contact patch because the tires are turned. You have more contact patch because the tires are wider and they are flat, and the cornering forces act to load those tires far more in the vertical direction than with a motorcycle, yielding large rectangular contact patches.

Hope this clears things up.

Ok, I apologize if I misworded my post. I know what I want to say and it doesn't always come out right by the time I type it.

First off I was trying to keep things simple and not start confusing people, esp new riders that may read this post. On "most" motorcycles, when you corner, traction is reduced because of the smaller contact patch that the tire has.

You have an oval tire () and take a corner, your contact patch is going to be smaller then if you are riding in a straight line. Plain and simple. I'm not refering to racing specifically. Just normal riding.

You are 100% correct on this: Contact patch size depends on tire profile, lean angle, and how hard you are on the gas. And with today's tire profiles, at full lean there is still a very large contact patch.

[No Worries]

Quiz: My old Suzuki uses a 130 width rear tire. If I put on a 180 tire (and appropriate wheel, same tire compound, same pressure, etc.) will the contact patch with me just sitting on the bike change? Will it get bigger in area? Wider? Longer? Smaller? Will the handling get better, ie. easier to change direction?

[Carolina]

Originally Posted by Carolina

Good read maybe I should print it out for the guys at work

Originally Posted by DLIT

It'll take thousands of sheets of paper to print it out.

Oh well I'll just use their paper

[Rider]

Originally Posted by No Worries

Quiz: My old Suzuki uses a 130 width rear tire. If I put on a 180 tire (and appropriate wheel, same tire compound, same pressure, etc.) will the contact patch with me just sitting on the bike change? Will it get bigger in area? Wider? Longer? Smaller? Will the handling get better, ie. easier to change direction?

What is the aspect ratio(sidewall height)? If they are equal (say 55%) then the contact patch would get longer and wider. No it will not be easier to change direction. More tire touching the surface equals more friction.

[No Worries]

Originally Posted by Rider

What is the aspect ratio(sidewall height)? If they are equal (say 55%) then the contact patch would get longer and wider...

That's what I always thought. But Archimedes proved us wrong over 2000 years ago. As the 130 tire is now, the contact patch is rectangular with the long dimension front to rear. With a 180 tire, the contact patch area will be the same according to Archimedes. The contact patch could now be rectangular with the long dimension left to right, or even square. Which is better for cornering traction? Long dimension front to back, or long dimension left to right? Which is better for accelerating out of the corner?

[Dave]

Originally Posted by ceo012384

Funny, I've had so many girls say this to me.

Man, if you're going to speak in such a haughty fashion, you should at least be right. You're not. This post is ridden with inaccuracies.

Have YOU done any reading on motorcycle physics?

- The contact patch doesn't get much smaller when the bike is leaned over with the profile of today's tires... the traction is not decreased.

- Contact patch size depends on tire profile, lean angle, and how hard you are on the gas. And with today's tire profiles, at full lean there is still a very large contact patch.

- The reason turns are a problem is because the centripetal forces of cornering are trying to 'shear' the tire. When accelerating in a straight line, the forces of acceleration as well as gravity squat the tire onto the ground and there is TONS of friction. When in a turn you just have gravity and a very slight acceleration, and then the cornering forces are ripping at the tire in a sideways fashion. I.e. in layman's terms, you're close to sliding. Think about it, if a carboard box were coming toward you on the ground, would it be easier to stop it by pushing against it, or by moving out of the way and pushing against the side of the box to try to stop is via friction between your hands and the surface?

- In racing, how are they only using a 'portion of the contact patch'? The contact patch is the portion of the tire in contact with the ground. They're using 100% of it. This is true for normal riding too, not just racing.

- In a car, you don't have more contact patch because the tires are turned. You have more contact patch because the tires are wider and they are flat, and the cornering forces act to load those tires far more in the vertical direction than with a motorcycle, yielding large rectangular contact patches.

Hope this clears things up.

man look what i started, thanks to ceo

[Mistress Maygin]

Originally Posted by No Worries

Not true. I have an older (1990) CBR1000 and the seat height is at least 2 inches shorter than the 1000RR, and the seat padding is five times thicker. And even though it's 200 pounds heavier than an R6, it's a zillion times easier to ride on the street.

If you read my post after that, it wasn't about the height so much as how big the bike is in width. If you put 3 bikes next to each other, all with the seat the same height off the floor, but one is a 1000, ones a 600 and the other a 250, "you" will set on each differently. At least I did with all the ones I sat on.

[Dave]

Originally Posted by Mistress Maygin

If you read my post after that, it wasn't about the height so much as how big the bike is in width. If you put 3 bikes next to each other, all with the seat the same height off the floor, but one is a 1000, ones a 600 and the other a 250, "you" will set on each differently. At least I did with all the ones I sat on.

right, but what NW is getting at is that you classified *all 1000s as being too wide for you. while it may not be a true 1000, im sure you wouldnt have any problems standing up my 954, its a pretty narrow bike behind the engine

[Mistress Maygin]

Originally Posted by Dave

right, but what NW is getting at is that you classified *all 1000s as being too wide for you. while it may not be a true 1000, im sure you wouldnt have any problems standing up my 954, its a pretty narrow bike behind the engine

Hmm, I see what you're saying. Didn't mean to generalize incorrectly. Remember, I am still new to this. The numbers are the size of the engines, yes? So wouldn't a 1000 pretty much be about the same size on every bike? The body and what not would be different, yes, but... Or am I completely off here?