URGENT! Flying with Brompton in the hold - deflate tyres?

[Fab Foodie]

Which bit of the Rhine are you on FF? Anywhere near me?

Duisburg/Homberg.
Anywhere close Auntie H?

[Auntie Helen]

I'm 30km from Duisburg so yes - but going back to England for a week tomorrow!

[T42]

"Excuse me, sir, but you have to deflate your CO2 cartridges."

[Auntie Helen]

Excellent timing for my holiday to Colchester... the central heating here has broken down so no heating or hot water for about five days (difficult-to-source spare part needed).

[rogerzilla]

Does the airline insist on deflating the aircraft's tyres, too? 

No, because they're 'soft' anyway.  They do calculate the maximum pressure at sea level to prevent explosions when cruising at 30000ft.  And if you really want some technical investigation of what challenges can arise, then how about the tyres on an aircraft that cruises at 70000ft such as the U-2.

I think the original question asked about 'hard' tyres and whether they required deflating to become 'soft' tyres.

I recall a fun day in Mallorca listening to quite a few inner tubes exploding in Muro while having coffee as the riders had left their 140psi inflated tyres in the sun.  Same principle, air can expand at an alarming rate, be it in heat or relative vacuum.

Descending a long steep hill on a front brake-only fixie is terrifying for the same reason.  A 400g rim has very little heat capacity and can get up to over 100 deg C very quickly (enough to make the brake blocks smell of singed Bakelite).  So that's about 1/3 increase in pressure if the air in the tyre reaches the same temperature, which is probably enough to pop a 140psi or even a 120psi tyre off the rim.

[Kim]

Bromptons, on the other hand, make up for lack of heat capacity in the rims with their superior aero-braking... 

[Biggsy]

...Especially with an S bag. 

There's a Brandt theory that it's not just increased air pressure that makes tyres pop off, but also the heat makes the tyre beads more slippery.  Not sure how true it is, but it would explain marginal cases when the pressure hasn't been all that outrageous.

[mark]

I would expect heat to soften the rubber around the bead, so Brandt's theory makes a certain amount of sense.

[Fab Foodie]

I'm 30km from Duisburg so yes - but going back to England for a week tomorrow!

Maybe close then, I tend to stay around the Moers area and travel into Reinhausen for work.

[Auntie Helen]

I'm in Kempen which is SW of Moers. I don't cycle that way too often as it's rather industrial (and round Kempen is fields and stuff) but there are still some nice routes to be found. I cycled to Landschaftspark Duisburg in the snow in January - that was fun!