Bald tyres on a car

kmb500

straggler wrote: »

Tyres are designed to be run with tread. Running without tread risks overheating and catastrophic failure. But you are welcome to find this out the hard way.....

Why aren't you allowed to drive on slick tyres? Is that a serious question?!

Yes its a serious question, I don't know much about physics but I would have thought that when there's more tyre (i.e. not full of gaps/tread) there's more friction so more grip. Formula 1 cars drive on slicks and they can go faster round corners due to their grip than anything else out there.

Retrogamer

Interestly i had a set of semi budget tyres that were close to the legal limit but still gripped very well, even in the wet.

I put on a set o brand new budget tires and even though there was much more tread, i had about 50% less traction in the wet.....

macman

kmb500 wrote: »

Yes its a serious question, I don't know much about physics but I would have thought that when there's more tyre (i.e. not full of gaps/tread) there's more friction so more grip. Formula 1 cars drive on slicks and they can go faster round corners due to their grip than anything else out there.

But only until it starts raining...

Johnmcl7

macman wrote: »

But only until it starts raining...

Yep, this is from near the end of the Blancpain 24 at Spa last year when it started raining and the cars didn't even manage to make it back to the pits before they were sliding about like they were on ice:

https://www.youtube.com/watch?v=y9boXa4Jtts

rich13348

kmb500 wrote: »

Yes its a serious question, I don't know much about physics but I would have thought that when there's more tyre (i.e. not full of gaps/tread) there's more friction so more grip. Formula 1 cars drive on slicks and they can go faster round corners due to their grip than anything else out there.

The gaps/tread is to allow water to escape out so there is grip. If there is no tread and no way to let water out you very quickly start aquaplaning.

F1 cars also have very sticky slick tyres that need to be at a specific temperature to work, hence the jackets and the weaving from side to side to warm them up. And they only last half or third of a race and need changed.

Do you want to put new tyres on every 50 miles?

kmb500

rich13348 wrote: »

The gaps/tread is to allow water to escape out so there is grip. If there is no tread and no way to let water out you very quickly start aquaplaning.

F1 cars also have very sticky slick tyres that need to be at a specific temperature to work, hence the jackets and the weaving from side to side to warm them up. And they only last half or third of a race and need changed.

Do you want to put new tyres on every 50 miles?

thanks, that makes sense.

on a dry flat road do slick or tready tyres have more grip, out of interest?

Car_54

kmb500 wrote: »

Yes its a serious question, I don't know much about physics but I would have thought that when there's more tyre (i.e. not full of gaps/tread) there's more friction so more grip. Formula 1 cars drive on slicks and they can go faster round corners due to their grip than anything else out there.

Schoolboy physics teaches you that friction is independent of area! See http://www.dummies.com/education/science/physics/how-surface-area-affects-the-force-of-friction/

Nasqueron

kmb500 wrote: »

thanks, that makes sense.

on a dry flat road do slick or tready tyres have more grip, out of interest?

Anecdotally from riding a bike, tread tyres are harder to get to speed and more work to keep going vs slicks, the difference between a 35mm knobbly tyre and 25mm slick is huge, I'd say more grip on the tread tyre

Joe_Horner

Car_54 wrote: »

Schoolboy physics teaches you that friction is independent of area! See http://www.dummies.com/education/science/physics/how-surface-area-affects-the-force-of-friction/

That holds for smooth surfaces but a tyre's grip is augmented by "mooulding" itself into the lumps & bumps of the tarmac which is why you get a lot less grip on a worn out road surface than a new one. That element of their grip is affected by area,

rich13348

kmb500 wrote: »

thanks, that makes sense.

on a dry flat road do slick or tready tyres have more grip, out of interest?

In not sure about that. Interesting question.

Given that F1 uses slicks on a perfect smooth tracks I am tempted to say slicks due to more surface area.

However this point is moot as you cannot in the UK guarantee dry road for more that an hour and flat road is never guaranteed.