[SmartCat]

Just curious!

F1/Nascar car tyres are as bald as Mogambo's head, and are called as "Racing Slicks". The idea behind using these tyres is that contact patch is more than grooved tyres, and hence the tyres are grippier when the track is dry.

Racing Slicks:


Wet Tyres:


Taking the same logic forward, as road tyres' tread wears out over 50,000 kms+, does the grip levels increase on our normal roads when its not raining? If no, why?

I see millions of taxis, buses and trucks with bald tyres and they seem to manage the grip/braking part fairly well - most of the time.

[Akshay1234]

The tyre compound on those tyres is very soft and sticky so it grips well. Even when those wear out over the course of the race, the grip levels do reduce. So to answer your question, bald tyres do not grip more than new ones in any condition.

[vikram_d]

Originally Posted by smartcat

Just curious!

F1/Nascar car tyres are as bald as Mogambo's head, and are called as "Racing Slicks". The idea behind using these tyres is that contact patch is more than grooved tyres, and hence the tyres are grippier when the track is dry.

Taking the same logic forward, as road tyres' tread wears out over 50,000 kms+, does the grip levels increase on our normal roads when its not raining? If no, why?

I see millions of taxis, buses and trucks with bald tyres and they seem to manage the grip/braking part fairly well - most of the time.

Not really. Road car tyres are at least 10 times harder than racing slicks even when new and moreover after 50k+ kms of usage they will only get harder. The tread in the tyres help in biting (for lack of a better word) the road and generate better grip.

Taxis, trucks and buses are pushing the limits of the tyres to the breaking point due to cost considerations.

[AlphaKilo]

Racing slicks have a softer compound and also are "heated" up(run at optimum temperatures) -> rubber tends to get slicker and more grippy. The reason for having treads in wet tyres are to expel the water and reduce "Aquaplaning". The treads are designed such a way to expel the water outwards away.

The normal road tyres are of a harder compound -> a compromise between slicks (mogambo style) and treads (mr. India style). Moreover, we do not run-in the tyres before we hit the roads everytime - we don't get warm up laps before going to grocery shop! Road tyres are more or less a compromise between different compounds and are not meant for high-speed F1 style driving.

On the funnier side: If we happen to run on "mogambo" style slicks during our daily use, imagine the pit stops we would have to do at our work place and more important at home! With better halves (for those who have!) standing near the house gate with the wheel nut releasing guns and spare wheels.

[ghostrider]

Absolutely not. The reason Racing Slicks are grippier is because of the tire compounds used to make them very soft and very 'sticky'. They aren't road legal, and even if they were, you wouldn't be able to use them in everyday conditions.

[Potenza]

As a basic rule for tyres the tyre that gives the biggest contact patch on a dry surface is the tyre which will provide more grip. A slick tyre provides a bigger contact patch than a grooved tyre and hence better suited for dry conditions. The grooves in the tyres are mainly to pump out water from under the tyre to prevent aquaplaning. Hence not only in F1/Nascar but also in Moto GP you will find slick tyres being used on a dry track and treaded or grooved tyres being used only when its wet.

However coming back to your question, a "bald" tyre will not provide more grip on a road going car on a dry surface simply because its completely worn and doesnt have any rubber remaining to lay down on the road surface in return for grip. In this case a grooved tyre will provide better grip simply because :1. It has more rubber remaining, 2. Because its not worn out completely it has stronger sidewalls and a stronger tyre casing which can take the load of braking and cornering.

[theMAG]

Slicks are super soft compounds while road tyres are h-a-r-d by comparison. For slicks, their grip comes from the compound, while for road tyres the grips is from the treads. So you see, having a road tyre sans tread is a rather bad idea !

[Sankar]

Theoritically yes, if the tyre compound hasn't become hardened/aged after long years of hard life and if there is enough grippy compound left remaining on the tyre carcass. But since generally baldness is associated with old age (in tyres and in humans) there is very little chance that the remaining rubber compound will be in its optimum molecular structure to provide good grip.

A shaved road tyre gives better performance on a dry track compared to full treads.
http://blog.caranddriver.com/the-los...-tire-shaving/
http://www.tireshaving.com/tire_shav...aving_info.htm

[AlphaKilo]

Originally Posted by theMAG

while for road tyres the grips is from the treads. So you see, having a road tyre sans tread is a rather bad idea !

1. How?

Well, logically speaking isn't it

"more the surface area available for contact with road = higher the road friction" ??

2. Harder the compound, better the chances are to survive a Foreign object damage(FOD) hence, make a tyre hard (may be possibly out of iron , i know i know you all would be wanting to kill me now! hey come on, we won't have any more punctures) and make them "mogambo ishtyle" hurray! Super grip! Isn't that what our trucks and taxi's doing? Desi ishtyle and technology!

(well, I assume to know the correct answer but for the benefit of everyone, it would be good if we discuss about the technical insights of it, which obviously I don't know!)

[GTO]

Racing slicks and bald tyres may look the same (i.e. treadless), but they are a whole world apart.

Bald road tyres have the *grippy* rubber completely worn out.

Of course, you can buy racing slicks for your road car, but they are meant to be used in bone-dry weather only (e.g. M3 CSL and its semi-slick tyres).

Example of a drag racing slick tyre (Pic Source)

[sgiitk]

The answer is an unequivocal YES given that other things being the same. Natural since there is more rubber in contact with the road. Softer rubber makes them even stickier.

[srishiva]

Since you did not say old tyres gone bald. I agree that they are more gripping in dry.

You did say after 50K kms. I guess they are hard, aged and would have lost their mojo.

[SS-Traveller]

Originally Posted by smartcat

...does the grip levels increase on our normal roads when its not raining? If no, why?
I see millions of taxis, buses and trucks with bald tyres and they seem to manage the grip/braking part fairly well - most of the time.

On a perfectly smooth tarmac surface designed for racing, with bald, evenly surfaced, soft compound tyres, you have more grip.

Do you have perfectly smooth tarmac surfaces designed for racing? - NO.

Do you have bald tyres? - YES.

Are the tread surfaces of your bald tyres even and flat? - NO.

Are they made of a soft compound? - NO.

You decide.

Can't help recall an incident from many years ago (1998). I was in a rush, and hired a Maruti Omni to transport me from Darbhanga to Patna. The vehicle had 4 perfectly bald tyres - zero tread pattern! And the ride was, to say the least, hair-raising. We almost ended up in a ditch a couple of times. And then I asked the driver, why he preferred to drive on bald tyres, considering that he couldn't control the car with them. Pat came his reply:

- "Ganje tyre puncher nahin hote." (Bald tyres don't puncture easily.)

- Huh? What? How? Why?

- "Yahaan lootne ke liye sadak pe keel daal rakhte hain. Ganje tyre mein keel nahin gaadhta, aur puncher nahin hota." (People scatter nails on the road to stop and loot cars. Bald tyres don't pick up nails and don't get punctured.)

I suppose lesser car control was a good trade-off to avoid being looted by thugs in the hinterlands of Bihar! Now where did you say you plan to drive to with bald tyres, smartcat?

[SmartCat]

Originally Posted by SS-Traveller

Now where did you say you plan to drive to with bald tyres, smartcat?

hehe!

A few years back, because of wrong wheel alignment, my car's new tyres became bald in just 4000 kms. So bald that I could see the metal (or is it nylon?) cords of the tyres.

But surprisingly, I had never felt any loss of grip during those 4000 kms, even on highways. I only realized something was wrong with the tyres after a short downpour - the car was slipping and sliding away, all over the highway.

On a perfectly smooth tarmac surface designed for racing, with bald, evenly surfaced, soft compound tyres, you have more grip.
Do you have perfectly smooth tarmac surfaces designed for racing? - NO.
Do you have bald tyres? - YES.
Are the tread surfaces of your bald tyres even and flat? - NO.
Are they made of a soft compound? - NO.

I guess we could add sand/dirt to that list - you will find them on our normal roads, but not on a race track. Loose sand/dirt/mud should, theoretically atleast, make a bald tyre lose grip.

[AlphaKilo]

Originally Posted by SS-Traveller

- "Yahaan lootne ke liye sadak pe keel daal rakhte hain. Ganje tyre mein keel nahin gaadhta, aur puncher nahin hota." (People scatter nails on the road to stop and loot cars. Bald tyres don't pick up nails and don't get punctured.)

I suppose lesser car control was a good trade-off to avoid being looted by thugs in the hinterlands of Bihar! Now where did you say you plan to drive to with bald tyres, smartcat?

Desi Improvisation! i am telling you! Someday, world (developed west) will follow our path!

Now comes another question: Is the tread design different (should it be?) for heavy vehicles(trucks/buses) from that of passenger vehicles (cars/bikes)? Why?(other than load factor is there any reason?)

OT: so bald tyres are for the thugs on the road, but how do you deal with the one in the driving seat? (taxi wallahs)