Nitrogen

[martinfan30]

any one else run nitrogen in your tires? i use it in my xr650l, my wifes shadow, and both our toyota's. we have a fill station at our shop and it is killer stuff. 1: it doesnt fluctuate in PSI with temp change. 2: it has larger molecules so it doesnt leak out like conventional shop air.

i just checked my tires after 3 mths. (i know this is a bad practice!) and the tires were still at 21 pounds like when i first filled them. good stuff!?

[PowerCell]

Explane: how do smaller molecules = less pressure loss?

[martinfan30]

glad you caught me! i did put smaller!! :bonk: :bonk:

i fixed it.

[Beyond The Pale]

The main benefit of using Nitrogen is that it comes extremely dry. Shop air usually has a lot of condensation in it. That gets to the rims and starts corroding them. The next benefit is that there is no Oxygen. Oxygen slowly eats at the rubber.

Air is already 78% Nitrogen, so I really don't get the less pressure fluctuations. Same goes for the less leakage. Again the Schrader valves use rubber, so no oxygen means less attack on them. Perhaps that is the reason for less leakage. Schrader valves are not made to really seal anyway. The best thing to do is use a good quality metal screw on valve cap. That stops the slow leakage on my bikes.

Smaller molecules = faster leakage. Again since air is already 78% nitrogen this makes little difference.

[martinfan30]

The main benefit of using Nitrogen is that it comes extremely dry. Shop air usually has a lot of condensation in it. That gets to the rims and starts corroding them. The next benefit is that there is no Oxygen. Oxygen slowly eats at the rubber.

Air is already 78% Nitrogen, so I really don't get the less pressure fluctuations. Same goes for the less leakage. Again the Schrader valves use rubber, so no oxygen means less attack on them. Perhaps that is the reason for less leakage. Schrader valves are not made to really seal anyway. The best thing to do is use a good quality metal screw on valve cap. That stops the slow leakage on my bikes.

Smaller molecules = faster leakage. Again since air is already 78% nitrogen this makes little difference.

ya i corrected my dyslexic first post. try it, they really dont fluctuate with a high percentage of nitrogen. i have been very happy with the nitrogen in my vehicles and all the other guys in the shop are satisfied also. this is why it is used for racing(i.e. NASCAR). ?

[Huffa 2]

You read my mind Martin! ?

I was JUST thinking about that an hour ago, remembering that I read some info on it somewhere and since I got brand new tires on I thought maybe I'd try it but wanted to of course ask on here 1st.

My thoughts were ..........does it help the tires run at cooler temps at all, probably not

Next thought, were the heck would I get it ?

What about Helium, what would that do, would it make the bike feel lighter ?

[martinfan30]

You read my mind Martin! ?

I was JUST thinking about that an hour ago, remembering that I read some info on it somewhere and since I got brand new tires on I thought maybe I'd try it but wanted to of course ask on here 1st.

My thoughts were ..........does it help the tires run at cooler temps at all, probably not

?

this is right out of the "NitroFill" brochure we give to our customers:

increase tire life up to 30%

reduce wheel corrosion(i know cleonard said this)

reduces tire running temperature

for more check out :

http://whynitrofill.com/

[Huffa 2]

Get the heck out, I deliver oil/gas to a company that has it

Who knows, might be able to get it for free and if not, how much should I be paying about ? Just for the L I'm talking.

I'll recheck the link, just looked real quick but do you know, can I buy it in a few cans that are set up to inflate the tires or it's one big machine with tank that it's in?

OH, I see the machine now

[martinfan30]

Get the heck out, I deliver oil/gas to a company that has it

Who knows, might be able to get it for free and if not, how much should I be paying about ? Just for the L I'm talking.

I'll recheck the link, just looked real quick but do you know, can I buy it in a few cans that are set up to inflate the tires or it's one big machine with tank that it's in?

OH, I see the machine now

not sure if you can put it in smaller cans. the purpose of the machine is it fills and fully deflates tires in 2-3 cycles. this gets the oxy out and increases the nitrogen percentage each time to at least 95%. not sure what it costs for a bike, 30 bucks for a car. you could probably go to a shop that has it and get your bike filled cheap.

[CTXr650L]

I remember when i used to work at an airport that all the jets used nitrogen in the tires to keep the pressure more consistent with the extreme changes in temperature they deal with.

Gotta think at altitude (35,000ft) they see temps in the -70 degree range or so, and after a stop on the runway there is enough temperature from rolling under load and braking that it would ruin the really expensive epoxy coatings on our aircraft hangar floor if we didnt park them on special mats.

When i used to race my car (road course) i kept track of tire temps and pressure as a tuning aid. I've seen as much as an 6psi change in pressure between a cold tire before a run and a hot tire after a half hour run. I would have liked to run nitrogen at the time to see if it helped as much as it did in the aircraft but it wasnt available to me at the time.

[HeadTrauma]

Paintballers like nitrogen for the same reasons mentioned here. The velocity settings don't fluctuate with temperature like they do with CO2.

What about Helium, what would that do, would it make the bike feel lighter ?

Since no else addressed it, I guess I will.

Helium is a actually a poor choice because of the molecule size. It is quite small and will actually diffuse right through the innertube rubber. Think polyethylene plastic and latex ballons are airtight? They are, but helium goes right through it. It also goes out through molecular-level leaks that air gasses largely cannot. In practicality, the weight reduction is so small that you would see more benefit by peeling a small decal off the bike or not having that second helping of dinner the night before.

[martinfan30]

I remember when i used to work at an airport that all the jets used nitrogen in the tires to keep the pressure more consistent with the extreme changes in temperature they deal with.

Gotta think at altitude (35,000ft) they see temps in the -70 degree range or so, and after a stop on the runway there is enough temperature from rolling under load and braking that it would ruin the really expensive epoxy coatings on our aircraft hangar floor if we didnt park them on special mats.

When i used to race my car (road course) i kept track of tire temps and pressure as a tuning aid. I've seen as much as an 6psi change in pressure between a cold tire before a run and a hot tire after a half hour run. I would have liked to run nitrogen at the time to see if it helped as much as it did in the aircraft but it wasnt available to me at the time.

just curious, how much pressure they run in those jets?

[martinfan30]

Paintballers like nitrogen for the same reasons mentioned here. The velocity settings don't fluctuate with temperature like they do with CO2.

Since no else addressed it, I guess I will.

Helium is a actually a poor choice because of the molecule size. It is quite small and will actually diffuse right through the innertube rubber. Think polyethylene plastic and latex ballons are airtight? They are, but helium goes right through it. It also goes out through molecular-level leaks that air gasses largely cannot. In practicality, the weight reduction is so small that you would see more benefit by peeling a small decal off the bike or not having that second helping of dinner the night before.

just dont supersize it!!

[Beyond The Pale]

I remember when i used to work at an airport that all the jets used nitrogen in the tires to keep the pressure more consistent with the extreme changes in temperature they deal with.

Gotta think at altitude (35,000ft) they see temps in the -70 degree range or so, and after a stop on the runway there is enough temperature from rolling under load and braking that it would ruin the really expensive epoxy coatings on our aircraft hangar floor if we didnt park them on special mats.

When i used to race my car (road course) i kept track of tire temps and pressure as a tuning aid. I've seen as much as an 6psi change in pressure between a cold tire before a run and a hot tire after a half hour run. I would have liked to run nitrogen at the time to see if it helped as much as it did in the aircraft but it wasnt available to me at the time.

Aircraft run nitrogen for two reasons. First is the the fact that most nitrogen is extremely dry. It is run to prevent water caused corrosion. Second is the high pressures that aircraft run accelerates oxygen reactivity. I spent 10 years doing engineering on fighter aircraft. They run tire pressures between 200 and 300 psi (F14=240psi). At those pressures the oxygen reacts rather quickly with the magnesium hubs and the rubber. That is why nitrogen is used.

Pressure changes with temperature closely follows the ideal gas law. It doesn't matter if it is air or nitrogen. Anyone remember PV=nRT ?

For racing on the pavement tire pressures are extremely important. A few psi can make the difference between winning and losing. The pressure is carefully set so it is optimum when the tires have heated up to racing temps. The pressure change between cold and hot can be a lot more than you think. I have seen changes as large as 10psi in my truck. All it takes is a cold day, a fully loaded truck and high speed interstate.

[Beyond The Pale]

Paintballers like nitrogen for the same reasons mentioned here. The velocity settings don't fluctuate with temperature like they do with CO2.

CO2 is a liquid in the cylinder. The vapor pressure changes a lot with temperature. However at a given temperature the pressure stays the same until the CO2 is used up. With a compressed gas the pressure drops continuously as you use it. I'm sure they use a regulator though since nitrogen has to be at 2000 or so psi to get a usable amount in a small cylinder.

Helium is even smaller since it is not even a molecule. It is just single atoms. Only about 1/6 the size of O2 or N2.

[Denn10]

CLEO why do you keep saying that nitrogen doesnt affect psi changes like air does? It is a fact that nitrogen it a tire vs air DOESNT change as much and it is a definite advantage over straight air. Thus you can keep pressures very close for racing applications where you dont have to get a tire to temp just to raise psi for optimal performance you only have to raise the temp for the rubber to be in its operating temp.

[martinfan30]

CO2 is a liquid in the cylinder. The vapor pressure changes a lot with temperature. However at a given temperature the pressure stays the same until the CO2 is used up. With a compressed gas the pressure drops continuously as you use it. I'm sure they use a regulator though since nitrogen has to be at 2000 or so psi to get a usable amount in a small cylinder.

Helium is even smaller since it is not even a molecule. It is just single atoms. Only about 1/6 the size of O2 or N2.

ive noticed this with my co2 "powertank". 500 psi in the tank until it is empty. the machine uses a "nitrogen generator", im assuming the regulator is part of that.

[dezracerE]

The Baja guys run it due to high speeds, heat and lots of sand.

I have started a race with 18 lbs and finished with 21-22.

Sand washes at 22 lbs sucks...

[Beyond The Pale]

CLEO why do you keep saying that nitrogen doesnt affect psi changes like air does? It is a fact that nitrogen it a tire vs air DOESNT change as much and it is a definite advantage over straight air. Thus you can keep pressures very close for racing applications where you dont have to get a tire to temp just to raise psi for optimal performance you only have to raise the temp for the rubber to be in its operating temp.

Spent too much time studying physics I guess. That and I guess that I'm splitting hairs a little too much. Sorry about that. I just have a hard time coming up with a reason for a large difference between nitrogen and air. The differences in the thermodynamic properties of nitrogen and oxygen are very very minor. Only a few tenths of a percent at most in the pressure ranges that we are talking about here.

A quick Google search has shown that the entire pressure change effect is due to the water contained in compressed air. When it's cold the water condenses lowering the pressure. It evaporates when it is hot raising the pressure. How much the pressure changes is a big function of both how much water is in the tire and how hot it gets.

Like I said before

1. Nitrogen is dry.

2. It doesn't have any reactive oxygen.

As far as I can tell other benefits follow from these two differences. The pressure changes less because it is dry. It's not a magical property of the Nitrogen. It a detrimental property of the water that is in the air. I don't think it applies too much to me out here on the fringe of the California deserts. We complain about humidity when it gets to 20%. I have never seen water inside on of my tires car, truck, or bike. I'll bet that there is a lot more water inside tires in say Miami.

Now how does this apply to our bikes. I'd say that the reduction in leakage is about the only positive effect. However, you should still be checking you pressures before each ride anyway. Without a home source of nitrogen this would be hard to pull off. I routinely ride a widely varying altitudes from sea level to over 10,000 feet. The pressure change there is almost 8 psi so I have to adjust my pressures often.

[martinfan30]

The Baja guys run it due to high speeds, heat and lots of sand.

I have started a race with 18 lbs and finished with 21-22.

Sand washes at 22 lbs sucks...

much better 3-4 lb. increase with nitrogen than 6-7-8 lb. increase with compressed air!