Tyres in the Sun Warning

[Rickshaw Phil]

I wonder if the issue could be that getting the rubber a lot hotter than normal exposes flaws in the material or in the fitting rather than it being the slightly higher pressure?

 

[Globalti]

Yes small gashes are able to stretch, which puts strain on the threads, which tear.

 

[midlife]

At absolute zero nothing will be moving so air pressure = zero?

 

[snorri]

I had a tyre explode, it was not a particularly hot day, I heard the bang as we topped Drumochter summit and thought it might have been due to an altitude thing but closer inspection at the end of the journey indicated that the rear mounted cycle rack was holding the bike tyre too close to the car exhaust pipe.

 

[FishFright]

[QUOTE 5359543, member: 9609"]its got to be somewhere though[/QUOTE]

It's still there but not exerting any forces. I think it's one of those things that work approaching zero Kelvin but gets hard to fathom at actual zero Kelvin. If such a temperature actually exists .

 

[nickyboy]

[QUOTE 5359543, member: 9609"]its got to be somewhere though[/QUOTE]
What happens as you cool air is eventually it liquifies. In doing so its volume is dramatically reduced. As you keep cooling further some parts solidify, with all except water reducing further in volume

So what you end up with a 0k is a tiny, tiny bit of solid "air, some little bit of supercooled liquid and nothing else. Hence the pressure exerted by this tiny tiny bit can be considered to be practically zero

 

[Tin Pot]

I've been thinking about this, probably due to the recent hot weather we have been having. When I was in my early teens, in the early 1970s, it was quite common for random elderly men (it was always elderly men) advising us kids to beware of leaving our bikes in direct sun. The reason being is that the tyres would deflate. This advice seems really strange nowadays, and I would never offer such advice to anyone as it seems totally pointless. I assume the logic of it was that the sun would warm the tyres and therefore the air inside would expand and leak out. The point of this post is that I was wondering whether there was ever any truth in it. Has anyone else been offered such advice? Bearing in mind that an elderly man in the early '70s would have life experience from approaching 100-years now (albeit you only have my word for it). It's very possible that tyre valves have improved a lot over all those decades, but I still can't help wondering that the valves are under more pressure during normal use than when the tyres are stationary but left in the sun.

People know virtually nothing, and assume virtually everything.

Ignore them.

 

[Drago]

Another old man talks sense.

View: https://m.youtube.com/watch?v=Hmc819RMVUE

 

[Tin Pot]

Another old man talks sense.

View: https://m.youtube.com/watch?v=Hmc819RMVUE

 

[Tin Pot]

It's still there but not exerting any forces. I think it's one of those things that work approaching zero Kelvin but gets hard to fathom at actual zero Kelvin. If such a temperature actually exists .

You mean Zero Point Energy.

It drives my ebike and espresso machine.

 

[marshmella]

I can vouch for the fact that the sun does have an effect on tyres. Back in the 1980s on a hot summer day, a young technician at work addressed me with "Oi Nick, your bike's just exploded". Going out to the bike rack which had a corrugated iron roof to investigate, I found the back tyre off the rim on one side and the inner tube in pieces.

Same thing happened to me in a beer garden. It was a warm day but not blazing hot . Bike propped against a wall about 15 yards or so from table when it went bang, i think most of the punters thought they were being shot at.

 

[Blue Hills]

My wife has a particularly illogical one of patting drinks cans before opening them to prevent them from spraying.
.

At the risk of a severe thread divert I cannot help but wonder what that's all about. Some OCD or a family memory - her mum always did it?

Great thread start by the way - I do remember these tales from my 60s/70s childhood - along with one bright spark's patented way of discouraging bike thefts - deflating his tyres whenever he parked up. Happy (small town) days - no one ever locked a bike that I recall.

 

[Tin Pot]

At the risk of a severe thread divert I cannot help but wonder what that's all about. Some OCD or a family memory - her mum always did it?

It’s the same way most superstition start and propagate. We have a tendency to rely on other people’s decisions about things - in many ways this can be helpful, save time, energy etc, but it also leads to this kind of nonsense.

Someone way back started saying that they tried tapping the can before opening, and they never had the spray calamity since. People don’t understand the physics, assume it’s true, don’t bother trying to evidence it, and tell other people.

...Assumptions.

 

[Blue Hills]

another family can/beer nonsense.

I know someone who in all honesty passed on a "tip" from her sister that a canned beer (I generally avoid anyway and prefer draught/spoons) can be kept fine for the next day by putting a spoon through the ring-pull slot and then putting it in the fridge.

The only clever thing about this is that the spoon "bowl", if upwards, stops the thing dropping into the tin.

If I ever see this person again I will enquire whether a fork works just as well.

 

[User269]

Meanwhile, back in the real world...............