Do you let air out of tires?

[Yellow Saddle]

Ah my (perfectly valid) schoolboy physics gas laws calc hadn't taken account of.softening or.degrading of the materials in a hot car

Ah but but but....the rubber softens and lose some tensile strength with heat but the cords don't, and they are the structural bits that keeps the shape, not the rubber. A car easily gets 60 degrees C inside - too hot to touch the steering wheel. Fire up that calculator again and redo that increase in pressure.

 

[Profpointy]

Ah but but but....the rubber softens and lose some tensile strength with heat but the cords don't, and they are the structural bits that keeps the shape, not the rubber. A car easily gets 60 degrees C inside - too hot to touch the steering wheel. Fire up that calculator again and redo that increase in pressure.

I think my calc stands, if not the conclusion. If it's 60C inside it must be, what, 30C outside. So that's 10% hotter in proper units 273+30 against 273+60

 

[AlanW]

Surely the tyre is responsible for providing the shape of the tube. Where does it distort to?

I agree that the tyre should make the tube retain its shape. However, from experience I have noticed that Latex tends to stretch more in certain places when kept at its working pressure for any length of time. That said, Latex tubes do drop 10 to 15 psi in 24 hours so in a week they would be near enough flat anyway I guess?

But I had a few issues with Michelin Latex tubes a few years ago and I wrote directly to Michelin UK Customer Support and that is what I was advised to do, so I do.

 

[Yellow Saddle]

I think my calc stands, if not the conclusion. If it's 60C inside it must be, what, 30C outside. So that's 10% hotter in proper units 273+30 against 273+60

Don't confuse me with facts.

 

[Cuchilo]

My tubs lose pressure all on their own .

 

[Smokin Joe]

I had a number of tubes blow out last year while leaving the bike in the car all day while i was at work.

I've had that on my way to a race, not blowing out but patches on repaired tubes (One on a clincher, another time with a tub) coming adrift with the heat.

 

[GrumpyGregry]

I only deflate my tyres if the bike is going on an aeroplane.

 

[Tim Hall]

I only deflate my tyres if the bike is going on an aeroplane.

Is that because you choose to, or the airline/ground agents ask you to?

 

[GrumpyGregry]

Is that because you choose to, or the airline/ground agents ask you to?

110 psi Kojaks at 11,000 metres....

iirc correctly I was asked the first time I did it and the rationale made sense for high pressure tyres.

 

[Lonestar]

{EDITED} I can't post that,I'm highly superstitious..

 

[Tim Hall]

110 psi Kojaks at 11,000 metres....

iirc correctly I was asked the first time I did it and the rationale made sense for high pressure tyres.

The most extra pressure the tyre will experience is another 14.7psi, assuming the (a) the hold is unpressurised and (b) you go high enough such that the external atmosphere is 0 psi. at 100,000 feet, atmospheric pressure is 0.16 psi. If we say your flight to CPH doesn't go higher than 35000 feet (roughly 11000m), external atmospheric pressure is about 3.5 psi. So the max differential your tyre gets is 14.7 - 3.5 = 11.2 psi.
Q1: Can your tyre at 110psi take another 11 psi?
Q2: Is your pressure gauge accuarate enough to tell?
Q3: Do you feel lucky, punk?
Q4: Can you tell I'm bored on a Friday afternoon?

 

[Profpointy]

110 psi Kojaks at 11,000 metres....

iirc correctly I was asked the first time I did it and the rationale made sense for high pressure tyres.

Except it it isn't. The luggage hold on a plane is also pressurised as it's much simpler engineering wise to pressurise the whole fuselage - a cylinder - than have various internal air tight bulkeads and only pressurize the top half. And in any case 110psi is 7 atm (above ambient on the ground) pressure - so even in outer space it would onky be 8 atm above ambient pressure - which is I'd guess, rather less increase than merely sitting on the bike.

That said, it's wiser to do as you're told then get hoy'd off the flight, but nonsense all the same.

 

[Markymark]

Most nights I let the tyres down, remove the wheels, brake pads and gear levers.

At the weekend I always remove the chain and delink them all, remove all cables, remove cassette, chainring and bearings. Then usually fortnightly I take the spokes apart and break the welding of the frame.

I find this routine helps preserve my bike. However I do spend on average 12 hours a day on this.

 

[numbnuts]

I like to ride on fresh air

 

[contadino]

I had a very close pass by a Bartoli delivery van this afternoon. Spotted it parked up a few km further down the road. Stopped and let down two tyres.

So yes. I do.