Then it's going to be "who has the best nitrogen".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?"
Costco rolling out self fill air stations
- Thread starter Kyle_E
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Madhatter
Well-Known Member
im heading to Costco
jbrown
Active Member
You are correct that the water does evaporate without boiling. This is water dissolving in the air, not a phase change. The amount of evaporation is determined by the saturation pressure of the water in air, which does vary by temperature. But the variance is pretty small over the temperature range a tire experiences. From 50 F to 150 F, the saturation pressure of water in air increases by about 3.5 psi. So, you would expect maybe a 3 or 4 psi change due to the water when there is some liquid water in the tire as the tire heats up. This is nothing like the pressure increase due to a phase change when the water turns to steam. But It certainly does add to the pressure variation compared to a dry fill.
WJBertrand
Ventura Highway
Water dissolving in air? 
If it’s no longer a liquid then it’s a vapor/gas, that’s by definition a phase change. If there’s a physical state in between, then you have discovered a new physical state of matter! Let the Nobel committee know immediately!
physical states of matter
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If it’s no longer a liquid then it’s a vapor/gas, that’s by definition a phase change. If there’s a physical state in between, then you have discovered a new physical state of matter! Let the Nobel committee know immediately! physical states of matter
Three States of Matter | Introduction to Chemistry
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jbrown
Active Member
You are, of course correct. There is liquid water and water vapor. My use of the word dissolved is just plain wrong. But the amount of water that transitions from liquid to vapor is small, and the 3 to 4 psi is what you would expect. (Saturation pressure is real, not made up like my new matter stateWater dissolving in air?
physical states of matter
Three States of Matter | Introduction to Chemistry
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)
Kyle_E
Well-Known Member
No beans in Texas Chili so, probably not in a gaseous state.Now I don't know what state I'm in.
WJBertrand
Ventura Highway
That additional few PSI will be in addition to the normal increase in pressure due to temperature. The tire ends up with higher warm pressure that predicted by simple thermal expansion. Doesn’t make much difference for us street riders, but for road racing, where they are right on the edge, splitting PSIs to get a fraction or a second better lap time, it’s significant.You are, of course correct. There is liquid water and water vapor. My use of the word dissolved is just plain wrong. But the amount of water that transitions from liquid to vapor is small, and the 3 to 4 psi is what you would expect. (Saturation pressure is real, not made up like my new matter state
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Good thing I'm not from Texas then.
Top Ten
Active Member
So, how do we genuinely take advantage of free nitrogen at Costco? I'm currently running old-fashion breathing air in my tires, and I want to switch over to nitrogen. Do I go to Costco, open my tire valves, try to squeeze out all the old air, then refill with nitrogen? I know I'm being stupid here on purpose. But really, how does the average guy make use of Costco nitrogen when he already has air in his tires. Do motorcycle shops that mount new tires filled with nitrogen help get you started? Do I always top-off with nitrogen and, little by little, replace the air in my tires? Asking for a friend...
My truck runs 65 psi. Set machine to 32 on all 4 tires. Then reset to 67 (tires warm) and hit them all again. Will do it again some warm day.
Kyle_E
Well-Known Member
You can mix and match nitrogen and air. The only thing is when you do, you loose the advantages that nitrogen offers.
The beauty of this thing, is Costco's are everywhere and now have free "air" 24/7 and you don't have to pay $2 at the gas station if you forget before leaving the house. Also the fact that the Costco stations will fit bikes tight space to fill. Where it is very hit and miss on what chuck the random 7-11 will have.
I had my Costco tire shop manager (hes a rider) dump and do a fresh fill of nitrogen on my bike. You could not do that at the self fill station as I think they need a 10psi or so back pressure to recognize they are hooked up to a tire.
B
ballisticexchris
Guest
Absolutely!! 32psi front and 36psi rear with good old 78% Nitrogen has served me well for over 45 years on my street bikes.
A 30 minute long wait in out of control Cotsco crowds for free air or to save 2 cents a gallon on gas is just not worth it to me. In fact going to Costco for anything is no better than Walmart. Both places are very last resort shopping.
That being said, if you work on your own suspension and keep a bottle of Nitrogen on hand then why not.......