Setting Tire Pressure in Cold Weather

[BC1100S]

But what about altitude? What if I start off in Death Valley on a 35F morning and climb a range of 10,000 ft. mountains where its 85F and come down again to 40F weather? It's so confusing!

Yes, I'm being facetious.

[GTRider]

But what about altitude? What if I start off in Death Valley on a 35F morning and climb a range of 10,000 ft. mountains where its 85F and come down again to 40F weather? It's so confusing!

Yes, I'm being facetious.

Not so facetious…

https://www.tirerack.com/tires/tiret...jsp?techid=167

I’ve seen altitude changes of >7k feet in a day of riding and watched the change on the TPMS display. Mostly what the above article points out is the value in checking your tire pressures every day on a ride.

Best,
DeVern

[RPGR90s]

Gernerally speaking you want about a 10% rise in temp from cold to hot (about 10-15 miles of riding).

My dad preached this to us kids back in the 70's as he was an engineer with Uniroyal.

[brownie0486]

Not so facetious…

https://www.tirerack.com/tires/tiret...jsp?techid=167

I’ve seen altitude changes of >7k feet in a day of riding and watched the change on the TPMS display. Mostly what the above article points out is the value in checking your tire pressures every day on a ride.

Best,
DeVern

I like climbing the higher elevations in Colorado in the summer. Mt. Evans is 14,200 feet as an example but there's a dozen peaks over 12K feet to get up as well out there.

We leave my brothers house at 9K feet, setting the tires based on current temp and using the formula mentioned [ 1 psi for every 10F in temp change ]. A difference of 5K feet. Once set in the morning, I don't pay any attention to tire pressures.

We were caught in a hail/sleet freezing rain last June on Independence pass. When we started the trek up over the pass it was 75F or so, I saw 35F near the top of the pass. A difference of 40F in less than an hours time. I never looked at the computers tire pressure reading, never do after I set the tires in the morning according to the formula discussed.

[Lee]

But what about altitude? .

98lee has a few good posts about TPMs and elevation in this thread.
https://forums.bmwmoa.org/showthread...er-says-no-fix

[BC1100S]

While I do appreciate the knowledge shown here by folks I hold in high regard, I'll just set my tire pressure first thing in the morning for wherever I am and.....leave it until I check it again the next morning.

[gordsmarsredrt]

While I do appreciate the knowledge shown here by folks I hold in high regard, I'll just set my tire pressure first thing in the morning for wherever I am and.....leave it until I check it again the next morning.

I'm with you. Check and as often as not adjust tire pressure before (most) every first ride of the day. Pre-ride inspection.

[easy]

What about the moon phase?

E.

[CABNFVR]

What about the moon phase?

E.

Check from the left side on waning moon. Lots of interesting info here, but I tend to fall into the check it with the TPM and just ride.

I was at a BMW rally many many years ago. Early one morning I kicked the front and rear tires with the side of my boot. (Wayyyy before TPM existed.) An old snarly guy addressed me with, "You can't tell how much air is in there like that!". I replied, "I'm not checking how much. I'm checking IF."

[BC1100S]

What about the moon phase?

E.

I was waiting for someone to bring that up.

[Omega Man]

Youse guys forgot to figuring how running nitrogen factors into middays pressure checks if it’s raining.

OM

[akbeemer]

The hard part is computing the effects of earth wobble.

[brownie0486]

The hard part is computing the effects of earth wobble.

We might have to become more aware of the Coriolis effect on our tires as well.

[BC1100S]

Dang, more stuff to think about.

[The_Veg]

And you absolutely *MUST* use the special air available only from your BMW dealer! It is specially designed for your BMW and your BMW is specially designed to use it. The performance will not be as the German engineers who know better than you do intended if you use any other air! ACCEPT NO SUBSTITUTES!