Team-BHP - Tyre Noise - Less noisy tires?

hi fellas,

i have observed that when i drive my ikon over cemented roads the tyre noise is awfully loud but as soon as i hit the tarred road , its feels someone has pressed the mute button !!

why do tyres on cemented roads make more noise than on tarred roads??

cheers

ps- this phenomenon has happened on every car i have driven

Probably coz cemented roads are a lot harsher and "give" a little less than tarmac. Thats also why the ride over cement is much worse than smooth tarmac. But, as cement lasts longer than the regular tar we use on roads, the Govt. has turned to using cement for the main roads.

Its the Porous nature of Tarmac which dampens the Tyre Noise,, When the air is forced out of the way of the contact patch of the tyre it causes a noise(called as air pumping i think

) , *now a tarmac road is *more porous than a concrete one so
the air trapped in tread grooves is able to leak into the road surface hence dampning the noise , a concrete road is hardly porous so the air becomes trapped and compressed ,*exciting the surrounding air and creating sound waves.

and like GTO mentioned .. since cemented roads are less porous they offer no drainage to the water , which remains stagnant and then ultimately results in aquaplaning.. which shlldnt be a problem for fellow team bhpians since we all put in countless dedicated hours of watching Schumi/Loeb/Tiff Nedell/ *

I have bridgestone s 322 tyres on my siena, 175 65r 14. noticed the tyre noise more from these than the regular good year cross plies on my fiat. Bridgestones are supposed to be inherently noisier. I had a choice between bridgestones and goodyears. But chose bridgestones coz they last longer than goodyears which have better grip and lesser tyre noise. had to compromise on this coz i knew i wud not get much of an oppurtunity to push the car hard.

Quote:

Originally Posted by [b

Quote[/b] ]But, as cement lasts longer than the regular tar we use on roads, the Govt. has turned to using cement for the main roads.

thats a debatable point. i have seen cemented roads in tatters within 6 months yaar

anyways thnks for the inputs

cheers

Yeah the speedbreakers are irritating, just after the flyover, they tend to kinda create a bottle-neck and start a traffic jam over the flyover and all, and the worst part is, (I mentioned this in another thread too) all the speedbreakers are uneven in size, thats the most irritating thing..
(its a horror for ppl having cars with low ground clearance, low profile tyres etc.)
And 1 more thing, now that this thread has become more of critisizing the road-system, i'd also like to ask, how many guys get irritated with that bumpy ride on the flyovers, I mean I dont know whether it is for drainage or just to cover the series of pieces of the bridge or what, but they have metal plates and the ride over the bridge is like after every 10-15 meters theres this bump. I cant seem to understand why they have it so carelessly put. Even the modern day flyovers have em'. I have not seen this anywhere except for India.

Hey N_C,

To add to what people have said above, tar is also much smoother than concrete, even those tiny ridges in the concrete add to the noise when they are being hit by your tyre several times per second.

About the debate of which is more dureable - concrete or tar. I dont have an unbiased answer, but i can definitely tell you that the ratio of mix of the cement in the concrete plays a huge part in how dureable it is, and as you know contractors will be more than happy to weaken the mix just to save a couple of bucks (read:crores).
[fyi - its concrete used in roads, of which cement is only a constituent]

N4S, i think bridgestones are noisier coz they tend to use a harder rubber compound (and hence last longer as well).

PS, The metal plates on flyovers are to cover the "expansion joints" in the flyover & road surface, which is basically a gap in the road to enable the road to expand and contract with temperature changes. Im not sure if this is the only function of the metal plates though. There are other ways to tackle the expansion joint in the roadsurface, but im guessin that they are more expensive and dont last as long!

Happened to stumble onto this page, chk it out - http://www.cmaindia.org/faq4.html

cya
Rehaan

Hello,

The tyre noise you mention has many reasons for this. In the case you have mentioned, you are asking as to why it is quiter on Tar roads than on the Concrete roads.

This is because the tar roads contain Bitumen which is like rubber. This not only helps in reducing the noise level, but also helps in better braking and road grip.

If any of you guys have noticed in Delhi and Mumbai in sharp corners they lay a special layer of this Bitumein sheets to make sure the tyre grips proeperly and accients are avoided. In some place in Bangalore also you can see. Next time I will make a note and give you the exact location.

It is this rubber cusion that reduces the noise.

Tyre noise is also different from tyre to tyre on the same road from manufacturer to manufacturer. This is because the tyre side wall or the shoulder of the tyre is designed to make less noise when rotating at high speed. So in some of the new tyres you will have less noise.

If you were to roll your windows and switch off your loud steros you will start noticing this.

All tyre manufactures take a lot of care to reduce the tyre noise. It is like the noise produced by the fan when rotating.

Ravi

hiya, i'm a new member.

i've changed rims and tyres on my swift and i seem to get an intermittent noise from the tyres. repeated wheel balancing and alignments have not settled the problem.

size: 15 inch HR rims with 38mm offset
tyres: 205/55 R15 Yokohama ES 100