Bikes on Planes - Tyre Pressures ???

les kennedy said:

Got my ticket - Got my hard shell bike box - Bike packed away.

Tyres ? Do I let them down or what ? I'm opting for the middle ground here at the mo - 100PSI in
them when they can take 140 PSI.

The airline may ask you to, but there's no reason logical reason why you should. Does the pilot let
his tyres down?

Quoted message said:

What would the pressure increase be in a hold on board a plane. I'm guessing that airplane tyres
never explode when they get higher - maybe they are different from 700 x 23's slightly, but the
idea is the same I think ?

The most difference the bike tyre will see is 14.7 psi - ie the difference between 1 atmosphere and
no atmosphere. So your 140 psi will seem like 154.7 psi. However it is unlikely that the hold is
unpressurised anyway so the difference won't be that great anyway.

Tim In space no one can eat ice cream

Though I never accepted that there was any necessity to reduce the pressure in my bike tires, I used to do it since othersise a baggage handler might let them down completely flat. I was transporting the bike intact with no case, just removed the chain and pedals, lowered the saddle, turned the handlebar sidewise to narrow the bike, and used a bungie to hold the front wheel pointed ahead while allowing it to turn. The bike always arrived in fine shape and I could have it ready to ride away in just a couple of minutes. It's possible to ride away on soft tires but not on flat ones.

I no longer have to worry about this because the airlines won't accept an unpackaged bike and because I now have a bike with S&S Torque couplings which unscrew to take the frame into smaller parts so it'll fit into a case small enough that the airlines accept it as a suitcase. The wheels will only fit if the tires are completely deflated though. Takes the better part of an hour to get the bike ready to ride too.

Bob Taylor

Quoted post said:

Originally posted by Les Kennedy
Got my ticket - Got my hard shell bike box - Bike packed away.

Tyres ? Do I let them down or what ? I'm opting for the middle ground here at the mo - 100PSI in
them when they can take 140 PSI.

What would the pressure increase be in a hold on board a plane. I'm guessing that airplane tyres
never explode when they get higher - maybe they are different from 700 x 23's slightly, but the idea
is the same I think ?

Flying into Geneva for next weekend. Some big bike race in a nearby country that sounds
interesting ?

Thanks,

Les

--

E-mail : [email hidden]

les kennedy said:

Tyres ? Do I let them down or what ? I'm opting for the middle ground here at the mo - 100PSI in
them when they can take 140 PSI.

Quoted message said:

Flying into Geneva for next weekend. Some big bike race in a nearby country that sounds
interesting ?

I recently flew one of my bikes to Zurich and the airline (Swiss) insisted I let my tyres down
fully. I just wheeled mine to check-in though, packed in a hard case they wont be able to see your
tyres and will probable accept whatever you tell 'em. The staff seemed a bit clueless really when it
came to travelling with a bike, which surprised me.

Bob
--
Mail address is spam trapped To reply by email remove the beverage

les kennedy said:

Got my ticket - Got my hard shell bike box - Bike packed away.

Tyres ? Do I let them down or what ? I'm opting for the middle ground here at the mo - 100PSI in
them when they can take 140 PSI.

What would the pressure increase be in a hold on board a plane. I'm guessing that airplane tyres
never explode when they get higher - maybe they are different from 700 x 23's slightly, but the
idea is the same I think ?

Flying into Geneva for next weekend. Some big bike race in a nearby country that sounds
interesting ?

Thanks,

Les

--

E-mail : [email hidden]

This is what BA have to say on the subject :

britishairways.comenOpen ↗

Pete

I have read that it is unlikely that that bike tyres will explode in an aircraft hold but it seams
that the airlines don't appreciate the science and prefer one to deflate tyres so they are soft(er
than 100psi). If they insist on looking at your bike my 50 pence would be on them insisting you
deflate them some more. They'll ask you if you have deflated them, you'll say yes they may let you
go. It depends I guess if the airport has a large x-ray machine (Stansted does) so they do not have
to see the bike or if they inspect it manually. Whats your issue with deflating them then ? Don't
want to take a track pump ?

Aeroplane tyres are different to bike tyres, they are inflated to much lower pressure and are
designed to be moved from sea level to 40,000ft and higher and can cope with the changes in outside
pressure, bike tyres are much less tolerant though more tolerant than airlines think.

"les kennedy" <[email hidden]> wrote in message
news:<[email hidden]>...

Quoted message said:

Got my ticket - Got my hard shell bike box - Bike packed away.

Tyres ? Do I let them down or what ? I'm opting for the middle ground here at the mo - 100PSI in
them when they can take 140 PSI.

What would the pressure increase be in a hold on board a plane. I'm guessing that airplane tyres
never explode when they get higher - maybe they are different from 700 x 23's slightly, but the
idea is the same I think ?

Flying into Geneva for next weekend. Some big bike race in a nearby country that sounds
interesting ?

Thanks,

Les

Tim Hall <[email hidden]> wrote in :"]news:[email hidden]:

Quoted message said:

les kennedy said:

Got my ticket - Got my hard shell bike box - Bike packed away.

Tyres ? Do I let them down or what ? I'm opting for the middle ground here at the mo - 100PSI in
them when they can take 140 PSI.

The airline may ask you to, but there's no reason logical reason why you should. Does the pilot
let his tyres down?

No he does not. But then aircraft tyres are not filled with the same stuff as our bike tyres.
Nitrogen is used.

Quoted message said:

Quoted message said:

What would the pressure increase be in a hold on board a plane. I'm guessing that airplane tyres
never explode when they get higher - maybe they are different from 700 x 23's slightly, but the
idea is the same I think ?

The pressure in a hold is maintained to the same as cabin pressure I believe, think AVI in transit
on this one, dogs, cats, often travel.

Quoted message said:

Quoted message said:

The most difference the bike tyre will see is 14.7 psi - ie the difference between 1 atmosphere
and no atmosphere. So your 140 psi will seem like 154.7 psi. However it is unlikely that the hold
is unpressurised anyway so the difference won't be that great anyway.

There should be very little difference, but possibly being asked to let the tyres down is a
precautionary measure more against baggage handlers using your bike to go to the canteen in the
other terminal. In the event of a hold de-pressurisation your tyres may be a problem, however the
catastrophic events which led to that means your last ride will probably be strapped into the seat
earthbound, possibly on fire with a watery grave awaiting. Dont worry about it......

Gibbo.

"John Gibson" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

No he does not. But then aircraft tyres are not filled with the same stuff as our bike tyres.
Nitrogen is used.

So which part of the normal Gas Laws (good O-level physics stuff -- but probably now beyond most
graduates) does Nitrogen disobey?

T

🙂

John Gibson schrieb:

Quoted message said:

Quoted message said:

The airline may ask you to, but there's no reason logical reason why you should. Does the pilot
let his tyres down?

No he does not. But then aircraft tyres are not filled with the same stuff as our bike tyres.
Nitrogen is used.

Which means that the difference is around 30% (air is ~70% Nitrogen, ~21% Oxygen and some other
elements).

Hans
--
Hans Friedlaender <http://hans.friedlaender.org> "Mommy, I'm going to paint a sun there now. Oh, it
turned out to be a whale!" Tobias, 28 Months.

"les kennedy" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Got my ticket - Got my hard shell bike box - Bike packed away.

I guess the hold could get very cold which would affect the tyre, but wouldn't that break loads of
stuff? So I guess the hold doesn't get that cold.

Anyway what happens when a tyre explodes, my guess is at most a small hole in the side wall an a bit
of noise, very muffled by the shell bike box.

Does anyone no what the airlines think the problem is.

les kennedy said:

Tyres ? Do I let them down or what ?

No. If they ask you to deflate them, ask them whether they insist on animals carried in the hold
being deflated too.

Dave Larrington - legslarry.beerdrinkers.co.uklegslarry.beerdrinkers.co.ukOpen ↗
===========================================================
Editor - British Human Power Club Newsletter
bhpc.org.ukbhpc.org.ukOpen ↗
===========================================================

MSeries said:

Aeroplane tyres are different to bike tyres, they are inflated to much lower pressure and are
designed to be moved from sea level to 40,000ft and higher and can cope with the changes in
outside pressure, bike tyres are much less tolerant though more tolerant than airlines think.

Are you sure. I can't find anywhere that actually states what the tyre pressures are but I've found
one article where a 747 was landed on a 30m runway (usually requires 45m) and "To meet the runway
strength limits the tyre pressures were lowered from 200 to 170 psi"

saoginc.com112002.htmOpen ↗

Tim.

--
God said, "div D = rho, div B = 0, curl E = - @B/@t, curl H = J + @D/@t," and there was light.

tjw.hn.orgtjw.hn.orgOpen ↗ locofungus.btinternet.co.uklocofungus.btinternet.co.ukOpen ↗

"Dave Larrington" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

les kennedy said:

Tyres ? Do I let them down or what ?

No. If they ask you to deflate them, ask them whether they insist on animals carried in the hold
being deflated too.

Amusing though that is, it doesn't actually make any sense, animals being capable of gaseous
exchange in ways that humans aren't.

Along the same lines though, one could ask them whether wheelchairs travelling in the hold need to
have their tyres deflated.

--
Mark South: Citizen of the World, Denizen of the Net "I wonder why so many Finnish traditions are
related with booze?"
- Juha Sakkinen

Mark South said:

Amusing though that is, it doesn't actually make any sense, animals being capable of gaseous
exchange in ways that humans aren't.

Well, you know that, and now I do too, but the average airline check-in lackey probably doesn't. And
it worked for someone I know flying to Europe from Captain Cook's Mistake...

Dave Larrington - legslarry.beerdrinkers.co.uklegslarry.beerdrinkers.co.ukOpen ↗
===========================================================
Editor - British Human Power Club Newsletter
bhpc.org.ukbhpc.org.ukOpen ↗
===========================================================

Was speaking to my boss who has a PPL.

for every 1000ft there is a 0.2 bar increase (relative pressure), with planes crusing at 35,000 ft
this means about 7 bar increase which is about 100psi.

apparently plane tyres have very low pressure in them at ground level but they are built to support
the plane with its construction / design rather than PSI.

When I have taken my bike on planes I had to let the tyres down completely.. tkae a pump!

hope this helps...

Gavin

"les kennedy" <[email hidden]> wrote in message
news:<[email hidden]>...

Quoted message said:

Got my ticket - Got my hard shell bike box - Bike packed away.

Tyres ? Do I let them down or what ? I'm opting for the middle ground here at the mo - 100PSI in
them when they can take 140 PSI.

What would the pressure increase be in a hold on board a plane. I'm guessing that airplane tyres
never explode when they get higher - maybe they are different from 700 x 23's slightly, but the
idea is the same I think ?

Flying into Geneva for next weekend. Some big bike race in a nearby country that sounds
interesting ?

Thanks,

Les

Thus spake "Frank X" <[email hidden]>

Quoted message said:

"les kennedy" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Got my ticket - Got my hard shell bike box - Bike packed away.

Quoted message said:

I guess the hold could get very cold which would affect the tyre, but wouldn't that break loads of
stuff? So I guess the hold doesn't get that cold.

If the hold gets cold, (the gas will contract) the tyres will get get softer & be less of a problem.
Decreasing atmospheric pressure is vastly overstated.

Quoted message said:

Anyway what happens when a tyre explodes, my guess is at most a small hole in the side wall an a
bit of noise, very muffled by the shell bike box.

Quoted message said:

Does anyone no what the airlines think the problem is.

^^^^^

Oxymoron alert!

--
Helen D. Vecht: [email hidden] Edgware.

Thus spake "Tony W" <[email hidden]>

Quoted message said:

"John Gibson" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

No he does not. But then aircraft tyres are not filled with the same stuff as our bike tyres.
Nitrogen is used.

Quoted message said:

So which part of the normal Gas Laws (good O-level physics stuff -- but probably now beyond most
graduates) does Nitrogen disobey?

Quoted message said:

T

Quoted message said:

🙂

Of course not! Air is 80% nitrogen anyway, innit?

--
Helen D. Vecht: [email hidden] Edgware.

Thus spake Hans Friedlaender <[email hidden]>

Quoted message said:

John Gibson schrieb:

Quoted message said:

Quoted message said:

Quoted message said:

The airline may ask you to, but there's no reason logical reason why you should. Does the pilot
let his tyres down?

No he does not. But then aircraft tyres are not filled with the same stuff as our bike tyres.
Nitrogen is used.

Quoted message said:

Which means that the difference is around 30% (air is ~70% Nitrogen, ~21% Oxygen and some other
elements).

Air is 79% Nitrogen, or thereabouts...

--
Helen D. Vecht: [email hidden] Edgware.

"Gavin Will" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Was speaking to my boss who has a PPL.

for every 1000ft there is a 0.2 bar increase (relative pressure), with planes crusing at 35,000 ft
this means about 7 bar increase which is about 100psi.

Well, he must have got his licence on Jupiter, Venus or somewhere, because here on ground level
Earth we only have 1 bar of atmosphere, and in the worst case 1 bar - 1 bar = 0 bar, not -6 bar

SteveC

"Helen Deborah Vecht" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Quoted message said:

I guess the hold could get very cold which would affect the tyre, but wouldn't that break loads
of stuff? So I guess the hold doesn't get that cold.

Quoted message said:

If the hold gets cold, (the gas will contract) the tyres will get get softer & be less of a
problem. Decreasing atmospheric pressure is vastly overstated.

I was actually thinking the rubber (or whatever it is may become brittle). Even going from 20 C to
-20 C would only reduce presure in the tyre just over 1 bar.

It's all nonsense of course, just idle curiosity.

Quoted message said:

Quoted message said:

Anyway what happens when a tyre explodes, my guess is at most a small

hole

Quoted message said:

Quoted message said:

in the side wall an a bit of noise, very muffled by the shell bike box.

Quoted message said:

Does anyone no what the airlines think the problem is.

^^^^^

Oxymoron alert!

I think the use of *no* for know was actually just a plain old moron alert ;o)