Serious question

[Finn]

We all know that cars can out corner bikes mainly because of the amount of rubber on the ground. Taking this into consideration, why doesn't my bike have a 190 size tire on the back AND front? While I realise the turn in would require a bit more energy, the grip would be most excellent... surely.

Go on, rip apart my hypothesis.

[dnos]

Why don't ya try it and see?
A bit of an experiment.

Oh and can ya video it too please so we can have a laugh.

[Finn]

While I also appreciate that most of the grip when accelerating and cornering comes from the back because of weight distribution, surely it would help for everyday riding??? Some scooters use the same size.

[onearmedbandit]

Look at 125GP bikes for your answer Finn. Tiny as tyres (width) yet out corner the MotoGP bikes (I realise there are other reasons they out corner the larger bikes, just giving an example of a bikle with excellent grip yet a narrow tyre). It's more to do with putting the power down on the road then actual cornering grip. From where I see it anyway.

[The Stranger:Me]

We all know that cars can out corner bikes mainly because of the amount of rubber on the ground. Taking this into consideration, why doesn't my bike have a 190 size tire on the back AND front? While I realise the turn in would require a bit more energy, the grip would be most excellent... surely.

Go on, rip apart my hypothesis.

Is the amount of rubber the biggest issue?
You see many people on real skinny tyres doing some real bloody fast laps.

I would have thought the biggest issue is countering the centrifugal force. A car has a large mass already inside the corner. The weight is transferred to the outside wheels on the car on a corner, thus virtually the entire weight is inside.

A lighter bike (or car) has less force acting on it in the corner, hence less to counter, thus better cornering.

Just a guess.

[White trash]

Too heavy to steer mate. You may think it's a little difference, but feel the difference between say a Widglide with a skinny front tyre and a Fatboy with a 130 section front tyre and you'll be amazed.

The effort required to turn the wheel in the "wrong" direction for counter steering is the issue.

[The Stranger:Me]

Odd that you feel the need to head it up as a serious question.

I think we have reached a milestone on KB. Finn's first serious post.

[Pumba]

After having a Holden SS with the widest rear tyres I have seen on a modern car (he was in frount till I passed him) folow me through the paraparas on the way to wanganui over easter I see the logic in your statement.....

However

Take the average tyre size of a run of the mill 250cc bike and the average tyre size of Chopper, I know what I would rather go into a corner with.

Just my two cents.

[Finn]

And why doesn't counter steering work on a car?

This one is for The Stranger...

[Crasherfromwayback]

Too big on the front also 'bump steers' badly

[The Stranger:Me]

And why doesn't counter steering work on a car?

This one is for The Stranger...

The same forces act on any wheel.
Problem with a car is it isn't going to lean because of the second track.

[ManDownUnder]

The smaller/tigher radius on the tyre gives a wheel an increased tendency to roll over (i.e. turn more easily). Makes sense to have that on the front as it's the most dynamic, influences steerage in addition to the up and down motion of the rear.

Once it starts to lean, the rear has no option but to follow...

[Ixion]

We all know that cars can out corner bikes mainly because of the amount of rubber on the ground. Taking this into consideration, why doesn't my bike have a 190 size tire on the back AND front? While I realise the turn in would require a bit more energy, the grip would be most excellent... surely.

Go on, rip apart my hypothesis.

Consider a car tyre. The tread area is flat across the tyre. The manufacturers try very hard to make it that way. Flatter it is , the more rubber on the road.

Now consider almost any bike tyre. Hm, the tread section isn't flat. It's curved.

Like a section of a circle.

Now, imagine a little circle. A narrow bike tyre. And draw a straight line tangentially to it. The road. Now imagine a big circle. A big bike tyre. Draw a tangential line. Notice something about the contact areas of the circle and the line? They're the same. Real world, not quite because the tyre deflects a bit and squashes flat. A fat tyre will squash a bit more than a little tyre . But not much.

And that squashing actually makes handling worse. because it makes the tyre into a flattish section tyre. Like a car tyre.

Imagine having a flat section tyre on your bike . (Sidecar tyres are like that). Now lean the bike over. Hm. What happens to that tyre. Oh, its either resisting leaning over and bulging a bit (you ain't gonna go round NO corners like that !). or it's tipped over onto the sidewall. Oh. big expensive painful bang.

Cars and bikes corner by TOTALLY different mechansims. Except for sidecars. And trials bikes. EDIT: In deference to Mr Motu : And flattrackers. And a few other odd ball types. And bikes going very very slow.

This has got to be THE most misunderstood issue in the whole of biking. The number of times I've answered it here. And every newbie that jumps out of a cage and onto a bike always asks it again. Gee. I want fatter tyres. No you don't .

On a bike - skinnier the tyre, faster you corner. Only reason to make rear tyres fat is because of the weight and power of big bikes. Little tyres would get ripped up. No reason at all to make front tyres fat.Except maybe comfort, big soft squishy tyres soak up bumps better.

But still we have things like the Honda Hornet, with a rear tyre wider than a Manx Norton. Cos Honda know that if they don't put a big fat tyre on it, ignorant newbies will go "Oh no, look at the skinny little tyres".

[doc]

Consider a car tyre. The tread area is flat across the tyre. The manufacturers try very hard to make it that way. Flatter it is , the more rubber on the road.

Now consider almost any bike tyre. Hm, the tread section isn't flat. It's curved.

Like a section of a circle.

Now, imagine a little circle. A narrow bike tyre. And draw a straight line tangentially to it. The road. Now imagine a big circle. A big bike tyre. Draw a tangential line. Notice something about the contact areas of the circle and the line? They're the same. Real world, not quite because the tyre deflects a bit and squashes flat. A fat tyre will squash a bit more than a little tyre . But not much.

And that squashing actually makes handling worse. because it makes the tyre into a flattish section tyre. Like a car tyre.

Imagine having a flat section tyre on your bike . (Sidecar tyres are like that). Now lean the bike over. Hm. What happens to that tyre. Oh, its either resisting leaning over and bulging a bit (you ain't gonna go round NO corners like that !). or it's tipped over onto the sidewall. Oh. big expensive painful bang.

Cars and bikes corner by TOTALLY different mechansims. Except for sidecars. And trials bikes.

This has got to be THE most misunderstood issue in the whole of biking. The number of times I've answered it here. And every newbie that jumps out of a cage and onto a bike always asks it again. Gee. I want fatter tyres. No you don't .

On a bike - skinnier the tyre, faster you corner. Only reason to make rear tyres fat is because of the weight and power of big bikes. Little tyres would get ripped up. No reason at all to make front tyres fat.Except maybe comfort, big soft squishy tyres soak up bumps better.

But still we have things like the Honda Hornet, with a rear tyre wider than a Manx Norton. Cos Honda know that if they don't put a big fat tyre on it, ignorant newbies will go "Oh no, look at the skinny little tyres".

Can you repeat the question

[BarBender]

Taking this into consideration, why doesn't my bike have a 190 size tire on the back AND front? While I realise the turn in would require a bit more energy, the grip would be most excellent... surely.
.

Was thinking the same thing as I slid home from work today...