[lilkim (OP)]

I know that car tires do not have innertubes, but bikes do why don't they pop when it is super hot outside?

B free!!!

[tony6789]

prolly because there is something added to the rubber so it doesnt pop

NEVER! underestimate youth

[lilkim (OP)]

ok, then why do they pop with too much air? same thing isnt it? you pump up the innertube and if too much air is put in it pops and darn it you have to go buy another one and try again....so when it is super super hot outside why does'nt the innertube inside pop? Doesn't the air expand? I don't mean the rubber i mean the inner tube. I've seen them go flat due to hot weather but not pop.....

B free!!!

[another_someone]

The problem is not that car types are in principle that different from bicycle tyres, it is just that car types have a much tougher job to do even in ordinary conditions, so they must already be designed to be much tougher.

Even without changes in weather, a car tyre has to support (shared between the 4 of them) about 1 ton of metal, and potentially be travelling anywhere from 70mph, to in excess of 150mph.  These tyres get very hot even on the coldest of days, so a few degrees more or less in the ambient temperature will not make that much of a difference to them.  The biggest problem for car types is usually not over-inflation (all that is likely to cause is that you lose control of the car because the tyres don't grip the road well enough), but under-inflation which causes more flexing in the tyre, which creates a greater buildup of heat as the car drives faster.

By comparison, a bicycle is only carrying the weight of a human being and a lightweight frame, and is not going to be travelling faster than about 30mph (some specialist bicycles will travel faster, even up to 80mph, but not your ordinary everyday street bike).  Also, because bicycles are so light, and are limited to the power that a human being can muster, the tyres must be exceptionally efficient in energy usage, and in weight; and will not be subject to so much heat internally generated, so they are built with less of a margin of error.

George

[neilep]

More tyre related goodness can be found here

http://www.thenakedscientists.com/forum/topic.asp?TOPIC_ID=1306

Men are the same as women, just inside out !

[lilkim (OP)]

ty niel...i will ck it out..

B free!!!

[tony6789]

the air doesnt expand enuf to allow the tire to pop

NEVER! underestimate youth

[4getmenot]

hmmm, ohhhh ok.

k

[4getmenot]

why not? it expands in a balloon.

k