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Old 27th September 2005, 20:36   #1
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Angry express way SCARY fact !!!!!

dudes..just got some scary facts about the mumbai pune expresway......thought ill share it with youll all...

when the expressway was being built...the constructors who were building it figured out that these roads wll be used at high speeds so to improve the grip on them they used handrakes to rake them while putting down the mix..these rakes were hand held and were like normal garden rakes and this dsign was meant for a specific purpose of increasing the grip onthese roads..
but this plan of theirs has backfirred bigtime because after various testing it has been found out that this rake design has led to the occurence of tremendous sound waves rebunding within the yres of vehicles moving over them...its like resonance of very high frequency ...and this can lead to tyres blowing up......it actually has ...
and it does not matter whether you have tubeless tyres cause it does not cause a puncture which would deflate slowly in a tubeless tyre...but this causes direct blowind up or shreeding of the tyres.....
they have tested he f1's, the potenzas and also some mrf tyres and at high speeds they have all directly blow away.......
it sounded really scary to me cause i am used to realy speedind down the expressway but i guess i wll be more careful now AND SO SHOULD U
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Old 27th September 2005, 21:02   #2
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honestly dude rubber making sound.........it will sound more like a fart

but seriously....sound is made up vibrations and i cant possibly understand what is going to vibrate,the tires or the road.Even if the tire vibrates at really high speed the sound is not going to be of a high frequency AND we are talking about rubber bursting due to a high frequency sound not glass!!If so then the latter would break first.IMHO tires burst due to heat and excess air pressure.
then again what do i know
fellow bhpians,please correct me if i am wrong!!

binz

Last edited by binz : 27th September 2005 at 21:05.
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Old 27th September 2005, 21:22   #3
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Oh well,
There goes the only road in India whenre one can safely drive fast in the mornings.
No more 160+ kmph.
Thank you for ruining my day.
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Old 27th September 2005, 21:59   #4
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Kindly elaobaret who is this expert.
NO NO NOOOOOOO. No tyre blowout happens due to all the funny facts mentioned. In fact it is very difficut to blowout a H rated ( 210 kmph tyre rating) at speeds of 140 -160 kmph.

Tube tyres usually blow out beacuse they deflate suddenely at low speeds and at such speedes the tyre litrely breaks away.

Just use 1 or two psi more than rated pressure, use tubless and forget about it. Doing mumbai Pune for last 3 years in Eagle tubeless and not a single problem

Even try to remember have u seen any single mumbai pune taxis in tyre accident

Last edited by pranil : 27th September 2005 at 22:01.
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Old 27th September 2005, 22:01   #5
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If they had tested Eagle F1s, Potenzas etc and they had blown at high speeds, the crashes would have been spectacular and we would have heard about it, don't you think?
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Old 27th September 2005, 22:12   #6
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Typical internet rumor i guess....it is very very difficult to blow
up a flexible material like rubber from sound.
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Old 27th September 2005, 22:16   #7
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dudes evenive being doing this way from the last two years and at very high speeds....its just that ive come to know about it today...its just that my uncles landcruiser tyre burst and got shreaded and it has happened before on his skoda with f1,s..its just that he asked some top notch authorities and thats what he got..and he told me and hence i informed you all.....its the rake pattern in the road thast causing this...and by the way the road has the most accidents per km in all of india and it is a single way road so a few are car-car crashes...i alone no of 9 cars that have burst tyres on this way and all were using the best....
and binz u say that tyres burst due to excessive heat and wrong tyre pressure doesent vibrations also lead to heat formation and sound waves can cause vibrations snd its not oly the sound as i said there are reverberations caused

Last edited by xtreme power : 27th September 2005 at 22:17.
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Old 27th September 2005, 22:45   #8
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1. Roadbuilding, especially those of expressways, is a special science and should not be based on constructers figuring out - during construction - that it would be used by high-speed vehicles and then trying to use garden rakes to make it suitable for such speeds. The figuring out should have happened at the design stage, not while laying the concrete, therefore I dont believe the garden rake theory.

2. However it is a fact that this stretch of road which is a dual carriageway has amazing stats by way of accidents, and its not like its the only such road in India. There is obviously something wrong somewhere, even if it is not a garden rake. When there are too many accidents of the same sort, someone has to study the pattern to find the common link that MAY have caused all these accidents, NOT write it off as a case of drivers going too fast or tyre pressures being wrong - as has been pointed out in many accidents, the car and tyre had been excellent.

3. Lamborghini shouldnt be driving around at 16 kmph, so he shouldnt be complaining about not being able to drive at 160.
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Old 27th September 2005, 23:10   #9
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i never meant the exact garden rake just wanted to specify the type of design and im sure this was thought about in the early perod before construction but taking speed into account and also this rake design was i think by some automated mechanism..not 2 sure but will deffinitely try and see this design the next time i travel....
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Old 27th September 2005, 23:14   #10
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OK guys give this poor lad a break will ya... he is just trying to educate us with conspiracy theories and such.
Next someone here will say that the constructor's of the express way have done this coz some external hostile government paid them so as to unnerve all the citizens of India into NOT using the express way so that it will affect commerce and stuff...
GEEZ GET REAL... this is like a sci-fi theory mixed in with a right winged conspiracy.
anyway thats my 2 cents worth...
Having used the express way even before it was opened... yes I sneaked in onto certain sections even before the mantri came and cut the ribbon...the only thing that the "HAND RAKE" marks do is give you a slight bit of tram lining for a little while.. nothing to get your knickers into a twist about people....
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Old 28th September 2005, 10:35   #11
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Quote:
Originally Posted by xtreme power
they have tested he f1's, the potenzas and also some mrf tyres and at high speeds they have all directly blow away.......
Dude, I am not flaming you. Butttt:

Who are these "they"? Are you telling us that the RTO has bought sets of Bridgestones, Michellins and Yokos for testing? And they also bought a couple of Octi RS machines for crash testing?

@Steeroid, my 2 cents here: Perhaps the drivers are not very familiar with driving at 160 kmph, as they cant do it frequently in India for obvious reasons. I think this too could be another contributing point...
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Old 28th September 2005, 10:58   #12
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Hand rakes are used on concrete road surfaces for 2 reasons:

1. To create some sort of grip on the surface. A smooth concrete surface is as good as a glass surface under wet conditions.

2. To dissipate the water from the concrete mix to collect on the surface. If water is allowed to settle on the surface, the surface tends to become brittle and will subsequently reduce the life of the concrete.

Tyres bursting due to sound vibrations is something to ponder upon!
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Old 28th September 2005, 11:42   #13
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Quote:
Originally Posted by Steeroid
....
3. Lamborghini shouldnt be driving around at 16 kmph, so he shouldnt be complaining about not being able to drive at 160.
LOL

btw nic post again Steeroid *up*
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Old 28th September 2005, 11:53   #14
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Quote:
but this plan of theirs has backfirred bigtime because after various testing it has been found out that this rake design has led to the occurence of tremendous sound waves rebunding within the yres of vehicles moving over them...its like resonance of very high frequency ...and this can lead to tyres blowing up......it actually has ...
Guess this is related to the phenomenon called Standing Wave effect (is that the right term???) Dont remember the term correctly. But remember reading about this one of the Autocar's guide about tires.

Its like when the wheel rotates, the tires are being compressed at the bottom and then relax. This causes a wave (really guys!) and this wave has a frequency that increases corresponding to the speed of rotation.

In case the frequency of rotation matches the resonance frequency (highly unlikely considering the r&d that goes into manufacturing these tires) then the tires would start resonating ie., the amplitude of motion will be high and the tires might tear or burst.

I am not sure how this can be related to the road surface

Will try to find some material regarding this on google today.
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Old 28th September 2005, 13:50   #15
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Quote:
Originally Posted by Harrie
Guess this is related to the phenomenon called Standing Wave effect ....

Will try to find some material regarding this on google today.
Here is some:

" every tire has a maximum speed limit at which a "standing wave" occurs along the tire circumference causing deformation, a temperature rise and eventual failure...."

http://www.sciencedaily.com/releases...1011071718.htm
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