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[cem_devecioglu]

Chris, playing game words whole night may be ok for you but I have other things.. bye

[feeutfo]

Chris, playing game words whole night may be ok for you but I have other things.. bye

Bye cem.

Notifications set phone on silent.

[feeutfo]

I wonder what dbug has to say?

[Kevin Wood]

Crikey! This is worse than discussing the merits of gold plated 13A plugs on a Hi-Fi forum.

Damn this subjective stuff. 

[dbdb]

Give me size and i'll give you the new ratings if that helps

Andy

Those ratings are absolutely meaningless, sadly, and are detracting from what the tyre manufacturers should be aiming for - grip and longevity, or a sensible compromise thereof. Not wanking around over fuel efficiency, which nobody gives a nants piss over.

Rant over, and breath

The fuel efficiency difference between the very lowest and very highest ratings is around 5%. So, in an Omega, about 1mpg. As most tyres fall in the middle, it makes absolutely break all difference, apart from allowing the greenies to copitulate up their favourite tree....  ....while the rest of us are sliding into said tree, causing far more damage to the environment, if you believe that 'dangle berries'.


Thanks for the offer AndyC, but not required, I have them. Unless you have access to proper comparisons (to Sport Maxx TT)

They are Fuel efficiency: E  Wet grip: A  Noise: 1 bar 68 dB.  Query answered, why are there 10 pages on this?

The new EU tests are brilliant and are scaring some manufacturers witless.  Or at least their advertising departments.

The difference in fuel use between an A and a G is 7.5%.  That's about £370 a year if you do 20,000 miles a year at 25mpg.

The problem with http://www.tyrereviews.co.uk is that the 'reviews' are just owners saying what they think their tyres behave like. It's not scientific at all. 

My guess looking at them is lovely in the wet (top wet grip rating), crap in mud and snow and wet grass.

[feeutfo]

Give me size and i'll give you the new ratings if that helps

Andy

Those ratings are absolutely meaningless, sadly, and are detracting from what the tyre manufacturers should be aiming for - grip and longevity, or a sensible compromise thereof. Not wanking around over fuel efficiency, which nobody gives a nants piss over.

Rant over, and breath

The fuel efficiency difference between the very lowest and very highest ratings is around 5%. So, in an Omega, about 1mpg. As most tyres fall in the middle, it makes absolutely break all difference, apart from allowing the greenies to copitulate up their favourite tree....  ....while the rest of us are sliding into said tree, causing far more damage to the environment, if you believe that 'dangle berries'.


Thanks for the offer AndyC, but not required, I have them. Unless you have access to proper comparisons (to Sport Maxx TT)

They are Fuel efficiency: E  Wet grip: A  Noise: 1 bar 68 dB.  Query answered, why are there 10 pages on this?

The new EU tests are brilliant and are scaring some manufacturers witless.  Or at least their advertising departments.

The difference in fuel use between an A and a G is 7.5%.  That's about £370 a year if you do 20,000 miles a year at 25mpg.

The problem with http://www.tyrereviews.co.uk is that the 'reviews' are just owners saying what they think their tyres behave like. It's not scientific at all. 

My guess looking at them is lovely in the wet (top wet grip rating), crap in mud and snow and wet grass.

Problem is, the sc5 where purchased by looking at very similar info. Based on a previous older model working well.

And turned out to be a nightmare. Would you spend another £5-700 odd quid again based in that experience? No I wouldn't either, hence the post for first hand experience.

[cem_devecioglu]

 
 
http://www.youtube.com/watch?v=zIy8VBYZiJM
 
do I see correct    its reaching lateral 1.0g
 
give me this tyre anyday

[feeutfo]

 
http://www.youtube.com/watch?v=zIy8VBYZiJM
 
do I see correct    its reaching lateral 1.0g
 
give me this tyre anyday

Maybe TB should complain, his omega didn't turn into a Porsche when he fitted sc5


I'm here all week.

[feeutfo]

And anyway, TB would kicks his arse on TT.

[cem_devecioglu]

 
http://www.youtube.com/watch?v=zIy8VBYZiJM
 
do I see correct    its reaching lateral 1.0g
 
give me this tyre anyday

Maybe TB should complain, his omega didn't turn into a Porsche when he fitted sc5


I'm here all week.

Fine, you have time to read this(these)
 
"Most writers call this quantity `slip angle.' I think this name is misleading because it suggests that a tire works by slipping and sliding. The truth is more complicated. Near maximum loads, the contact patch is partly gripping and partly slipping. The maximum net force a tire can yield occurs at the threshold where the tire is still gripping but is just about to give way to total slipping. Also, I have some difficulties with the analyses of slip angle in the literature. I will present these difficulties in these articles, unfortunately, probably without resolution. For these reasons, I give the quantity a new name.
A tire is an elastic or deformable body. It delivers forces to the car by stretching, compressing, and twisting. It is thus a very complex sort of spring with several different ways, or modes, of deformation. The hypothetical tire implied by with constant would be a non-elastic tire. Anyone who has driven hard tires on ice knows that non-elastic tires are basically uncontrollable, not just because is small but because regular tires on ice do not twist appreciably.
The first and most obvious mode of derformation is radial. This deformation is along the radius of the tire, the line from the center to the tread. It is easily visible as a bulge in the sidewall near the contact patch, where the tire touches the ground. Thus, radial compression varies around the circumference.
Second is circumferential deformation. This is most easily visble as wrinkling of the sidewalls of drag tires. These tires are intentionally set up to deform dramatically in the circumferential direction.
Third is axial deformation. This is a deflection that tends to pull the tire off the (non-elastic) wheel or rim.
Last, and most important for cornering, is torsional deformation. This is a difference in axial deflection from the front to the back of the contact patch. Fundamentally, radial, circumferential, and axial deformation furnish a complete description of a tire. But it is very useful to consider the differencesin these deflections around the circumference.
Let us examine exactly how a tire delivers cornering force to the car. We can get a good intuition into the physics with a pencil eraser. Get a block eraser, of the rectangular kind like `Pink Pearl' or `Magic Rub.' Stand it up on a table or desk and think of it as a little segment of the circumference of a tire. Think of the part touching the desk as the contact patch. Grab the top of the eraser and think of your hand as the wheel or rim, which is going to push, pull, and twist on the segment of tire circumference as we go along the following analysis. "
 
from
http://www.pelicanparts.com/techarticles/physics_racing/part10.htm
 
total
http://www.pelicanparts.com/techarticles/physics_racing/

[cem_devecioglu]

and I find this post quite interesting
 
"The school physics books tell you that the coefficient of friction is a constant, but in reality this is an oversimplification. In the case of tyres, the coefficient of friction drops off as you increase the weight on the wheel. This is why you can tune a car's handling by adjusting the anti-roll bar, and also why you *can't* tune with anti-roll bars if the load on the tyres is too small (the vehicle is overtyred).

Because of this, the bigger the contact patch the more grip you can get. In a drag race, dropping the tyre pressure increases the contact patch area and increases grip. Even on road bikes you will see people dropping the tyre pressure to almost nothing for the absolute maximum grip down the strip.

BUT, when you look at lateral grip (side force) other factors start to matter. The tyre develops side force because of the slip angle between the tyre and the road. This slip angle means the tread is being pulled sideways by the road surface. At the front of the contact patch the deflection is relatively small. As you move back along the contact patch the deflection increases steadily. At some point, the sideways forces in the tyre exceed the friction between the tread and the road and the tread starts to slip relative to the road. When the tread is slipping like this it produces less grip on the road. Now imagine increasing the slip angle and imagine what effect this has on the side force. As the slip angle increases the sideways deflection builds up quicker so the front of the contact patch works harder. But more and more of the back of the contact patch is sliding and losing grip. At some point you reach a maximum point where more slip angle means less side force because you are losing more grip at the rear of the contact patch that you are gaining at the front. This is often referred to as 'breaking away' where you ask the tyre for more grip and end up getting less.

The longer the contact patch is, the more gradually this break away occurs. If you shorten the contact patch, the break away occurs more abruptly but you get more absolute grip at the peak. This is because there is less variation in sideways distortion between the front and back of the contact patch, more of the contact patch reaches maximum grip and starts to slide at the same point. Having a shorter contact patch also means you get less self-aligning torque so there is less feedback through the steering about how close the tyres are to breaking away.

When you fit wider tyres, what you're doing is making the contact patch wider and shorter for the same tyre pressure. This means you get a more abrupt breakaway but more grip right on the limit. The disadvantage is more expensive tyres, more tramlining and steering kickback, more wind and rolling resistance and noise, less grip in slippery conditions, a more abrupt breakaway to catch out the unwary driver and less warning through the steering about how close the tyres are to breaking away. "

[feeutfo]

Not read it yet, cut and paste helps no one.

Having spoken to Dunlop, again, matching tyres to a specific chassis is absolutely key. Hence manufacturers approve a tyre specific to that model.


Eg ...There is no guarantee a tyre that works on a golf, will work on an omega.

Now to read.

[cem_devecioglu]

Not read it yet, cut and paste helps no one.

Having spoken to Dunlop, again, matching tyres to a specific chassis is absolutely key. Hence manufacturers approve a tyre specific to that model.


Eg ...There is no guarantee a tyre that works on a golf, will work on an omega.

Now to read.

dont know who you talk to but he did tell you story

[feeutfo]

Cem quoting random segments from google helps nobody, we know enough about slip angle. Thanks.


I'll ask again, how do you explain the tram lining oddity on sc3 mo /ao1?

[feeutfo]

Not read it yet, cut and paste helps no one.

Having spoken to Dunlop, again, matching tyres to a specific chassis is absolutely key. Hence manufacturers approve a tyre specific to that model.


Eg ...There is no guarantee a tyre that works on a golf, will work on an omega.

Now to read.

dont know who you talk to but he did tell you story

Again your an expert on something you have no experience of.

A term In uk " knows everything, knows nothing" almost aplies.

As always, every answer under the sun except a helpful one.