a science problem about tires... help me!?

Question

The purpose of the thread on tires is to increase their grip on the road. If you agree with this statement, then 1) why do drag racers use "slicks" (tires with no thread) and 2) why do brake linings have no thread?

Answer 1

I'd check for a source on this, but I believe that smooth tires give more traction because they have more surface area on the road than tires with tread. The tread is to channel water to keep vehicles from hydroplaning when the road is wet.

For the second part of your question, do you also mean tread (rather than thread)? Same answer - the flat surface gives a larger surface area for more friction which would give more stopping power (at least until the brake pads wear down).

Answer 2

Slicks or some Dot-R track tires actually have tread, they simply lack a tread pattern... but that's just a technicality. A slick offers more possible contact patch, which means more grip. The compounds and carcass construction of these tires is also vastly different from road tires, but looking at just the tread, more contact between the tire and the road means more grip... same with brakes (but more on that in a moment).

Introducing a tread pattern is to help the contact area find a surface that it can contact. If you've ever driven on race tires, you'll know that a little lose road gravel or sand could cause you to lose all contact... and of course, even light rain would leave you unable to steer or stop. Tread patterns allow the tire a channel to move such debris to, letting the block of the pattern reach the road, and grip. The pattern does not increase grip (it actually decreases it), but it allows the other area better grip.

So, brake linings: same issue, the larger the contact area between the brake pad and disc (or shoe and drum), the better it can grip. But, if you look at a brake pad, you will usually see two groves, and if you look at many discs, you may see slots. While you do not have the exact same issues with tires, you can get gases that form under the heat and friction of braking which decrease the ability of the pad matieral to grip against the rotor, the groves or slots allow these to escape... similarly a small decrease in maximum swept area in exchange for maximizing the grip for the remaining area.

Answer 3

Tread, not thread. The reason is because you can't predict what kind of surface you'll be running on. Slicks also have a soft composition in order to have maximum adhesion, but are never used on a wet track. The tread on a regular street tire will channel water out of the contact patch to avoid hydroplaning. Slicks will hydroplane on a wet road, and it won't have to be that wet. A friend of mine slid his car off a turn into a creek--with bald tires. If the tires had tread, the car probably would have stayed on the road. The road was wet. As far as brakes, you don't usually have a water problem. Disc brake pads are forced so hard against the disc that they plow the water aside. But I had the same problem as hydroplaning with mountain bike brakes in the rain--they wouldn't grip the rim. This is similar to a disc brake, and also similar to the bald tire situation. I almost went through a stop sign. There's a trick that was used by dirt bike riders in the past, when drum brakes were more common. File diagonal grooves in the surface of the shoes so any water that gets in is channelled to one side, allowing the shoe to make contact with the drum that much faster. Otherwise, the shoe will hydroplane on the drum until the water is squeezed out. I did that on my own bike.

If you're dealing with a completely dry surface, there isn't much advantage to having tread. The only advantage left is that the tire is more flexible. That's a really big advantage, though. You can have a thick tread with a flexible surface, which gives good tire life while keeping the tire cool. If the tread were that thick and solid, it would really heat up at highway speeds. You'd be bending a thick piece of rubber instead of a thin piece of rubber with nubs.

I should add that the reason we filed the brake shoes is because we'd go plowing through streams. Wouldn't always make it, of course. But your buddies were always there to drag it out and laugh at you.

Answer 4

1) The word is "tread". "Thread" is what screws have.
2) The tread increases grip on a wet road. Drag racers use untreaded tires on dry roads but not on wet roads. Loop (Nascar, Formula One, etc.) racers use untreaded tires when the pavement is dry and treaded tires when the pavement is wet. This is not legal on public roads because prohibiting all use of untreaded tires is the best way to ensure that we do not use untreaded tires in the rain.

Answer 5

Slicks give the most traction in DRY weather, but the streets don't always stay dry, so treaded tires are required for all weather use.

Some high performance brake linings DO have slots in them, but brakes are not tires, so it's a different thing here.

Answer 6

the tread on a tyre is used to disperse water (when it is raining) that is why race cars change to a tyre with a tread when it is raining. A slick tyre forms a wave of water in front of it when the road is wet causing aquaplaning. now imagine every one using slick tyres on the streets when it starts raining

Answer 7

Newtons regulations of action inertia products in action tend to stay in action in a immediately line till acted upon via a stress The handbag is vacationing on the fee of the vehicle, as is each and every little thing contained in the vehicle