Costco rolling out self fill air stations

Kyle_E

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Just a heads up might want to check the local Costco. They have free air (well nitrogen actually) filling stations now. Probably rolling out across the states.

Locking chuck, you set the pressure digitally on the head unit and it stops right on the number. So convenient I won't bother to use the pump at home anymore. Not sure if they are only on during operating hours, But will check tomorrow.

Went to get air in the truck tires today and notice my old local one had two pumps with designated parking spots right next to the tire center. Went back on the bike to see if their chuck was small enough to fit. Had to do a tiny fiddle with the rear, but no problem at all really.
 

Sierra1

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Nitrogen would be pretty cool. Discount Tire doesn't even offer that. They say it's too hard to find, and replace if you get a puncture.
 

Kyle_E

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Nitrogen would be pretty cool. Discount Tire doesn't even offer that. They say it's too hard to find, and replace if you get a puncture.
You can mix reg air and nitrogen. It just dilutes the nitrogen and makes running it pointless. So if you do get that puncture, you have to drain and refill the tire next time you get a nitrogen source. I will say running it in the truck this past 2ish years I will happily keep running it. Today was the first day in that time my TPMS has gone off. Typically in the past it would go off several times a year on the weather changes.

Now that I know I have easy access to it at costco, will drain and refill the bikes there sometime soon.
 

bigbob

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The thing with nitrogen is it is dry, no water vapor. When the tires heat it is water that expands changing the pressure.

Took my truck to Costco and set machine to 32 pounds. Did all 4 tires. Then reset to 67 (+2 from 65 because warm) and redid them.

TPMS has been good since all reading within 1 pound of each other.
 

Kelvinator

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I've used the Costco "air" station several times now, it's very close to where I live. I can confirm it is available even when the store is closed. Very convenient to do a pre-ride top off on fuel and air. Also noteworthy, you may NOT completely deflate your tires thinking you will get a full load of nitrogen. If your tires are below a certain level of air it will not fill them. You would have to have the tire shop guys do it from their machine. I've never tried that.

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WJBertrand

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The thing with nitrogen is it is dry, no water vapor. When the tires heat it is water that expands changing the pressure.

Took my truck to Costco and set machine to 32 pounds. Did all 4 tires. Then reset to 67 (+2 from 65 because warm) and redid them.

TPMS has been good since all reading within 1 pound of each other.
If water is present as vapor already it won’t expand any more than any other gas. The problem is if there is any condensation, i.e. liquid water present, heating will cause it to change phase. Water vapor occupies magnitudes more space than liquid water and that’s what causes the pressure swings. Nitrogen is dry because the processing to separate it from air leaves the water behind. You can make air just as dry as nitrogen and it will behave exactly the same way, thermodynamically, as pure nitrogen. None of this really matters for street use though.


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Checkswrecks

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Most commercial air compressors have a water separator near the outlet of the tank, especially if a shop is using that air for pneumatic shop tools to keep them from rusting.
 

Kyle_E

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I've used the Costco "air" station several times now, it's very close to where I live. I can confirm it is available even when the store is closed. Very convenient to do a pre-ride top off on fuel and air. Also noteworthy, you may NOT completely deflate your tires thinking you will get a full load of nitrogen. If your tires are below a certain level of air it will not fill them. You would have to have the tire shop guys do it from their machine. I've never tried that.

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Yeah the way the pump works on the backfeed to let the machine trigger and read the pressure is probably something like 15-20 PSI. Good tip. The guy that runs my tire center is a rider so figured he'd have no problem with doing the initial air exchange.
 

WJBertrand

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Most commercial air compressors have a water separator near the outlet of the tank, especially if a shop is using that air for pneumatic shop tools to keep them from rusting.
True, but their effectiveness depends on regular maintenance, even then they only remove most of the water.


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jbrown

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As far as water trapped in the tire changing state goes, water at 46.7 psi (that's 1 atm + 32 psig) boils at about 277 degree F. So the trapped water will stay liquid in our tires.
 

WJBertrand

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As far as water trapped in the tire changing state goes, water at 46.7 psi (that's 1 atm + 32 psig) boils at about 277 degree F. So the trapped water will stay liquid in our tires.
Not true, water can change state from liquid to vapor well below boiling temperatures via evaporation. If you don’t believe it explain how puddles evaporate? There would never be any humidity below boiling in that case as well.


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Sierra1

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Most commercial air compressors have a water separator near the outlet of the tank, especially if a shop is using that air for pneumatic shop tools to keep them from rusting.
You're absolutely correct. . . . but, I can't afford their set-up. I drain my compressor after each use, but that doesn't fix the problem. I always check my tires before I leave anyway. That way my gauge is showing me "cold" (ambient temp) psi. Nitrogen would only do me good if I had the capability to do it at home.

. . . . If you don’t believe it explain how puddles evaporate? There would never be any humidity below boiling in that case as well.
Tires are a closed system. Nowhere for it to go. Otherwise you're right.
 

Kurgan

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Here in MIchigan (and Ohio and Indiana to a degree) Belle Tire has a very large presence and each location has a free computerized air station on the side of the building. Set the desired pressure and let it do it's thing. I've compared their gauge with my Blue Point dial gauge and theirs shows 1lb higher consistently - close enough.

Nice and convenient for the SUV since I don't have access to my compressor and I am not going to use a manual bicycle pump for that volume of air. Motorcycle tires, no biggie to use the hand pump to add a few pounds here or there if need be.
 

WJBertrand

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You're absolutely correct. . . . but, I can't afford their set-up. I drain my compressor after each use, but that doesn't fix the problem. I always check my tires before I leave anyway. That way my gauge is showing me "cold" (ambient temp) psi. Nitrogen would only do me good if I had the capability to do it at home.



Tires are a closed system. Nowhere for it to go. Otherwise you're right.
Correct, the water is still present but at least some of it can still change phase back and forth from condensed to vapor and vice versa, at temperatures well below boiling. That’s what makes tire pressure so variable with ordinary air that has some degree of vapor in it. If that weren’t happening there would be no pressure stability advantage to using dry nitrogen. As the air in the tire warms, it’s ability to carry more water vapor increases. If your bike is parked overnight in the cold, there might be a few tiny droplets of water that have condensed inside the tire. As the tire and tire air within warms, the greater moisture capacity of the warmer air allows more of the water to enter the vapor phase. Simple physics.


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Top Ten

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I see a whole new set of memes coming. It used to be "What oil do you run?" or "What's the best tire?" 2021 has brought us "Air or nitrogen?" o_O
 

Checkswrecks

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I see a whole new set of memes coming. It used to be "What oil do you run?" or "What's the best tire?" 2021 has brought us "Air or nitrogen?" o_O
I've seen threads like this on other forums and yes, people can get ridiculous.

But then we already knew that.
 
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