[Shan2nu]

I recently had a flat on my Vtec. The tube had been ripped at more than 2 places. Not wanting to take any chances with it, i decided to replace the tube, but the place where i'd taken the tyre didn't have any Bridgestone tubes. That guy showed me some JK tube, which in the first place, didn't look like it could handle the kind of speeds the Vtec is capable of.

On asking him about the tube, he said that the tube was meant to be used in a 175/65 R 14 tyre. What about speed rating, i asked him?

Oh well tubes arent rated for speed, that's only for tyres, he said. And I must admit, that even after searching the tube, i could find no speed or load rating written anywhere on it.

But inspite of all this, I rejected his offer and went to the nearest, authorised bridgestone dealer in town. Luckily, he had the recomended tube in stock. When i asked him about the speed and load ratings for a tube, i got the same answer.

As per these guys, there seems to be no such thing as a speed or load rating for tubes. I'm still not able to digest that. Imagine you fit a MRF or JK tube, in a bridgestine tyre which is "T" rated (good for 190 kmph). How do i know if the tube inside is good enough to handle speeds upto 190 kmph?

Maybe all Bridgestone tubes for 175/65 R 14 "bridgestone" tyres are T rated, but that doesn't mean all the other companies follow the same rule.

Maybe the JK tube that guy showed was infact S rated (good for 180kmph), you never know as there's no indication given on the tube.

So, the next time you plan to replace the tubes in your tyres, please make it a point to use the same brand and size as that of the tyre.

Be careful, coz one small mistake like this, can have "Devastating" results.

Regards...
Shan2nu

[Shan2nu]

After a little searching, i came apon this page where all the recomemded "JK" tyre sizes for indian cars is given, no doubt the size is right but note that the speed and load rating is still absent.

http://www.jktyre.com/passenger-cars...city-vtec.html

Regards...
Shan2nu

[F50]

Hey thanks for the info Shan2nu ....

[shravan316]

Thanks for shedding light on this very important aspect Shan2nu....never thought of this earlier.

[Dippy]

Better still.. go tubeless

Dippy

[GTO]

I'd presume that when they give the speed rating for a tyre, its for the tyre and tube included.

But its still scary that there arent individual ratings. Its an irony that the fastest car in my house is the ONLY one with tubed tyres

GTO

[nitrous]

guyz, when i visited blore last weekend, i did around 100-125 kph average speed on my ceat nylon tyres. do u think that was dangerous ??

[Shan2nu]

Originally Posted by [b

Quote[/b] (nitrous @ July 09 2004,09:38)]guyz, when i visited blore last weekend, i did around 100-125 kph average speed on my ceat nylon tyres. do u think that was dangerous ??

Usually all car tyres can manage doin 125kmph without damage.

Here's a table that willsort out your problem. On your tyre, look out for it's speed rating, usually marked with an alphabet. Then get back to the table and see upto what speed your tyres can be driven.

Max Car Speed Capability

Speed

Symbol KPH MPH
L 120 75
M 130 81
N 140 87
P 150 95
Q 160 100
R 170 105
S 180 113
T 190 118
U 200 125
H 210 130
V 240 150
W 270 168
Y 300 186
Z 240+ 150+

Regards...
Shan2nu

[Rehaan]

Well speed ratings range from A-Z.
The slowest speed rating being A1 tires (5km/h MAX ) ..but ofcourse those arent passenger car tires!

The thing to keep in mind with the speed rating is that as the tires get older or get more worn out you should keep lowering the "speed rating". There is some general rule of thumb ie subtract Xkm/h off the given speed rating for every 10,000km the tire travels and 5km/h for every month the tire is old. But i dont know the specifics... sorry!
Also, the way speed ratings are specified, is under controlled conditions, and i believe it is the maximum speed the tire is designed to sustain for a period of one hour. (Am i right??)
Also, its very important that you are running the correct tire pressure for a high speed trip.

cheers
R

[killjoy]

Originally Posted by [b

Quote[/b] (Dippy @ July 08 2004,23:32)]Better still.. go tubeless

Dippy

[GTO]

Originally Posted by [b

Quote[/b] ]5km/h for every month the tire is old.

Nope, that sounds like a little too much. In a year, the speed rating of your tyre comes down by 60 km/h? Its probably 5 km/h for every year or something.

Will do some research and update

GTO

[Rtech]

Shan2nu, GTO, without meaning to sound rude, I really fail to understand how or why you continue to drive one of the fastest cars in India on stock tubbed rubber.

I could understand the "aam janta" doing this as they are not really knowledgeable vis-a-vis the safety aspects of driving on tubeless tyres, but for 2 extremely automobile literate people to do this is, IMO, inexcusable.

A set of good performance tyres costs as much as a decent music system does, but yet, the first thing people do is spend a load of money on their system! I really don't understand this. The first thing I did with our new car was drive it to the tyre shop and switched from the stock rubber to Eagle F1's. This is even before I took the car home!

Things like better speakers can wait...I want to feel safe when I drive at 170kmph.

Switch over guys, before its too late.

Rtech

[Shan2nu]

Originally Posted by [b

Quote[/b] (rtech @ July 09 2004,22:07)]Shan2nu, GTO, without meaning to sound rude, I really fail to understand how or why you continue to drive one of the fastest cars in India on stock tubbed rubber.

Dude, try telling that to my dad.

I've been looking out for tubeless tyres from day one, but dad doesn't want them changed right now. Now how can you argue with that?

I've also been trying hard to get these tyres to wear asap, so that i can get a reason to get them replaced, but [img]http://www.team-bhp.com/iB_html/non-cgi/emoticons/***.gif[/img] , these tyres don't seem to be wearing off. 40K kms and there's still a lot of life in them.

Things never happen when you want them to......LOL!!

Regards...
Shan2nu

[Rehaan]

Originally Posted by [b

Quote[/b] (GTO @ July 09 2004,11:11)]

Nope, that sounds like a little too much. In a year, the speed rating of your tyre comes down by 60 km/h? Its probably 5 km/h for every year or something.

Will do some research and update

GTO

There is some general rule of thumb ie subtract Xkm/h off the given speed rating for every 10,000km the tire travels and 5km/h for every month the tire is old. But i dont know the specifics... sorry!

Meant to say "Y"km/h.
As is said i dont know the specific figures. Will try n get them as well.

cya
R

[Rehaan]

Hey Rtech,

Man...i dont know why but i was going crazy because i seemed to remember seeing your tires looked like eagle f1s! lol
Glad i have that confirmed now!

Originally Posted by [b

Quote[/b] ]The first thing I did with our new car was drive it to the tyre shop and switched from the stock rubber to Eagle F1's. This is even before I took the car home!

Ditto.

cya
R