Don't the bezels use a rubber gasket? Would low pressure cause that gasket to expand even a little bit, making it tougher to turn the bezel?

Just my first random thought. Physics is like magic, right?

 

The same thing happens with my old Breitling Navitimer. The bezel (slide rule) becomes very hard to turn at cruising altitude. I understand that when the pressure inside the watch becomes higher than the one outside it, crystal and bezel are pushed out and this prevents a smooth rotation.

Proof of that is obtained by pulling out the crown during the flight: immediately the bezel rotation goes back to normal. The reverse is not so evident, after landing I don't really need to let the outside pressure get inside the watch to obtain a smooth rotation.

 

Funny, I just came from a trip using airplane, experiencing the same boring moment and ending up playing with my Orange Monster bezel. But I didn't think the bezel became tighter.
And if you say that the pressure inside the watch becomes higher than the one outside it, well... I'm sure it would NEVER push the bezel out, as the bezel is an independently separated mechanical part outside the watch case, and not related to the "inside" of your watch. And I think the cabin pressure only had a very little effect to human body. It should NOT affect your watch mechanism. ANY of them. At least that's what I understand from the Seiko Monster, as I'm not really a scientist ;-)

 

.

 

hey guys are you kidding?
the airplane is pressurised so you are at an altitude near the sea while flying in terms of pressure xD

 

Yeah, that's why my ears never pop while flying.

I vote for some kind of relativistic phenomenon involving time dilation....

 

Watches are not all made in the same way. The revolving bezel of the Navitimer includes the crystal which rotates together with it so in some way it is part of the case. Of course most watches are made differently. At cruising altitude the pressure in the cabin corresponds to approx 5,000 feet and that is a significant difference in respect of the pressure at sea level.

 

Airliners are generally pressurised to simulate conditions at 8000 feet. Air pressure at sea level is around 14.7 pounds per square inch, and at 8000ft its around 10.9psi. So if your watch was assembled at sea level there will be around 3.8psi trying to get out when at altitude.
I suppose its feasible (depending on the design of the watch and condition of the seals) that this internal pressure could force the crystal and crystal gasket to push or bow out (as mentioned by someone earlier) a tiny amount and this could set up an interfernce with the bezel.

 

I don't think that applies on pressurized passenger airliners. They use pressure to negate the external effects of the altitude. What you're talking about would be unpressurized airplane. But those will never fly that high in the first place... Time for Mythbusters?

 

The 10.9psi at 8000ft is chosen because its perfectly comfortable for us but stresses the airframe far less than the 14.7psi we normally live with (aeronautical engineering 101). Put a 3.8lb weight in your hand and imagine that pressing outwards in all directions, thats what you actually have inside a well sealed watch at altitude in a pressurised airliner, this is how pressure differential works.
I have no idea if this is enough to press out the crystal or seal slightly, but basing the theory on the fact that these are designed to withstand pressure from without and none from within, it is theoretically feasible.
Because they are designed to withstand external pressure this could also explain why they took a day to return to normal at sea level pressures.
Microscopic gas pockets in the bezel o-ring are also a feasible cause for the same reason as above, ie pressure differential.

 

Correlation does not equal causation ;-)

I say it was a coincidence.

 

Ditto.

I just don't believe a pressure change of 4PSI would cause any distortion in the case or crystal of a Monster to cause any bezel interference. I don't believe a bezel gasket would change dimensions either.

Something caused the bezel to be more difficult, but it wasn't because the watch was on an airplane at altitude. This is reinforced by the statement about it taking more than a day to go back to normal. It didn't take more than a day to become more difficult to move, so it taking more than a day to go back to normal means it's from some other cause.

 

More likely that the bezel oring is expanding under reduced air pressure.

 

Interesting read. http://www.rlhudson.com/O-Ring Book/diagnosing-causes5.html

 

Dry air if anything

 

That's a great suggestion!

 

I like all of the pressure theories, but I can understand the pressurized cabin argument too. This is a little off the wall, but does anyone think that the altitude of the plane might have an inertial effect on the bezel? Meaning that because the watch is so much further out from the earth and coupled with the speed of the plane, the watch is expanding due to inertia.


Sent from my iPhone using Tapatalk

 

Interesting comments - thanks folks. I do find it odd that after some hours after landing, it worked as normal and has been ever since. It's nothing I'm worried about - just a mere curiosity.

I've got another trip coming up in April so, I'll retest my OM. I'll wear it onboard just as I did previously and after flying at cruising altitude for an hour, I'll try moving the bezel. If it's difficult to turn, my next action would be to unscrew the crown. If there is any pressure inside the watch, it would normalize with the cabin...which may result in the bezel turning easier/normal. This would validate the theory about the pressure in the watch.

Dan

 

there is no theory, cabins are pressurized, so no theory.

 

It's aliens!


Sent from my iPad using Tapatalk

 

One way to test how good the pressure is onboard would be to open a plastic bottle while at cruising altitude and cap the bottle at that altitude. It will look normal when you land if the pressure is as suggested. If there truly is lower pressure up there, the bottle will have collapsed due the higher pressure on the ground. This is a little thing I like to do when I go up and down a mountain. Even just 5000 feet in elevation can have clear effects on the bottle.