Reducing air pressures (tyres/shocks) for flying

Apologies if this has been asked before but I can't seem to find an answer using the 'search'

Haven't flown with a bike for a few years, but was always told to let air out of the tyres. Back then my forks were elastomer though. Now I have air forks and a rear air shock. Worth letting some or all of the air out? Also, I've got tubeless wheels that are sloshing about with fresh stans sealant so I'm not keen on letting them down really.

What's the pressure drop like in the hold? If it's, say, 50% and I leave 20psi in my tyres then presumably the tyres would feel like they have 40psi for the duration of the flight – which is no big deal…

They put dogs and cats in the hold….so, what pressure drop are you talking about?

I've never let air out of my tyres or shocks on all the flights I've done.

Do they? I don't know, that's why I'm asking. I just assumed the hold wasn't pressurised like the cabin was, hence them asking you to drop tyre pressures.

Some airlines ask you to let air out of tyres, but they have never heard of an air fork or shock.

Holds of passenger aircraft are pressurised, so your tyres will be fine.

Even if the hold was a total vacuum the effective pressure will only be increased by 14psi.

Since the hold is pressurized, probably to at least 2/3 sea level pressure you are talking less than 5psi difference.

I'm pretty sure they don't let the air out of the plane's tyres when it takes off.

How about if it tried to take off on a conveyor belt?

lol

Ah fair enough, I shan't worry then. Cheers!

Even if the hold was a total vacuum the effective pressure will only be increased by 14psi.

I could be talking crap but I would imagine that effective pressure is more to do with ratios than absolute values. A 28psi tyre at sea level has a 2x pressure differential from one side of the rubber to the other. Drop outside pressure to 7psi and there's now a 4x differential. Drop to 1psi and there's a 28x pressure difference (equivalent of running nearly 400psi at sea level)

As I type this, I'm starting to think I'm talking bollards actually… 😉

edit: yes, I'm definitely talking rubbish

How about if it tried to take off on a conveyor belt?

You did that on this forum too?

Sorry
😉

jase, step away from the beers!

never let tyres or shocks or forks down before but i tell them i have every time they ask.
keeps them happy.

They ask you to let the tyres down simply so that the bike doesn't try and roll all over the place.

air pressure at sea level is about 15 psi.

if you put your tyres in a vacuum, it would be like adding 15 psi into the tyre.

aircraft holds are pressurised – to at least 10 psi.

it's sometimes necessary to deflate your tyres to fit them into a bike bag, but you really don't need to do it from an 'explosion-prevention' point of view…

last thing you want to do is mess up your carefully tweaked settings on your shocks and forks. +1 on letting the tyres down to save a bit of space in the box/bag. Also it normally pays to let the bike stand upright when you reach your destination so any oil/air issues can correct themselves.