[monstertex]

I was talking to a friend that has been drag racing cars for a while now and he told me he was going to start using nitrogen instead of compressed air in his tires so they won't expand due to the amount of heat. I thought this to be a good idea to try on my bike because of the hot weather in summer. Does anyone know any benifits or drawbacks to doing this? Thanks.

 

[Speeddog]

AFAIK;

Using dry nitrogen just gets you a consistent/repeatable increase in pressure with increase in temperature.

The pressure increase of air with temperature depends on how much water is it (humidity).

It's an issue for a drag racer, as even small changes in air pressure drastically effect the performance of the tires. IMHO, it's not an issue for street riding.

If you've got easy access to a nitrogen tank with the appropriate regulator, there's no harm in it that I know of.

 

[Guest]

I'd heard that if you're concerned about internal corrosion (from the water vapour in the air in the tyre) then nitrogen is the way to go. This must be for magnesium wheels more than for alloy / steel wheels, I guess...?

 

[monstertex]

I wasnt really looking at performance with the dry nitrogen, unless my superbike sponsorship comes through, hah! What I was really looking at was the Texas heat gets nasty in July and August. That combined with the mass in the saddle I think I'd be better off with the dry nitrogen than air so I could run the correct air pressure. Maybe I'm trying to get too technical, but wouldn't that be better than running on less air pressure? Thanks fer the info I'll let you know if he gets the retgulator and if he'll hook me up with a little bit.

 

[Guest]

Nitrogen is so passe'. ;D

There has been experimentation and allegedly, actual use of a inert (noble) gas for the Daytona 200.

I didn't catch if the announcer/commentator actually mentioned the specific inert gas used.

 

[capww8]

IMHO... check your pressure before you ride, and you won't have any problems... your tire temp isn't going to change drastically enough to effect anything.

Also... I'm fairly certain nitrogen fills are the norm in F1 racing... but those tires probably heat up a bit more than a pair of p. dragons :-D

 

[mikef4uk]

I also engineer race cars-quite succesfully i might add as well, the advantage of Nitrogen--as said earlier(speeddog) is it is moisture free,moisture is the worst thing you can put in a race tyre as the tyre will see temps above 100deg C, and the moisture content then causes large pressure differances when out on the circuit, but which have calmed down when the car returns to the pits for a tyre pressure check--causing much confussion,Nitrogen expands in much the same way as air--air is after all nearly 80% nitrogen anyway,from the corrosion point it is probably a good idea,but cold/hot pressures will not change,like i said,it`s used because the moisture conent should be zero-and repeatable

 

[fastbike]

Nope, not inert. Not flammable maybe, but compressed air isn't going to be hazardous because of flammability.

The reason that nitrogen is used in racing (per my buddy who supplied the Long Beach Grand Prix for several years) is that it is inert. They use it to run all their air tools and don't need anything blowing up. Thus that's what their tires get as well.

 

[byl]

the only valid point here is for the moisture, the rest is loads of c**p : . Here in France petrol station charge 10$ for people to pump up their tyres with Nitrogen cause it is not leaking out of the tyre! lets think scientifically :
air is 80% N2, 20% O2 (to simplify, will get ride of other gases!)
If you charge with compressed air, that's what you have in your tyre. Now the O2 is leaking, after a while you'll be left with only N2 in your tyre. Top up with compressed air, you now have 80% N2 + 20% top up with a composition, of 80/20. Your tyre will have 96%N2 and 4% O2.
O2 leak again, then top up again!
96% N2 + 4% of top up (80/20), you have then 99.2% N2 and .8%O2.
Do it another few times and your tyre will be nearly full of N2!!

 

[Capo]

The "ideal gas law" demonstrates to us the fact that the volume of a gas at a constant pressure is directly proportional to the temperature of the gas within its gaseous range. This would mean that any element which attains a gaseous state at a temperature below that of oxygen would gain less pressure as a result of a given increase in temperature (for the sake of example, we'll consider a temperature increase from 80deg F to 180deg F, or equally, an increase from 299.81K to 355.37K). Oxygen becomes a gas at 90.2K (Kelvin), increasing in volume (or increasing in pressure within a fixed volume) by a factor of .209, Nitrogen becomes a gas at 77.36K, increasing by a factor of .199, Helium becomes a gas at 4.22K (the lowest temperature for gaseous form in known elements), increasing by a factor of .158. Relating to the proposed situation at hand, logic would dictate that Nitrogen is superior to common air. Helium would be superior to either of the two.

 

[clarkkent_41101]

You can do all the calculations is the world, but you won't know your moisture levels without a humidity meter. You can't just fill your tires with nitrogen and expect there to be zero humidity. Residual moisture is still present unless you purge your tires. I know at least in NASCAR they purge their tires with nitrogen 3-5 times, but even then, they use a meter to be sure the purging reduced the humidity to low enough levels. If you are only street riding, you probably have no need to use nitrogen. It would take some hard core street riding to increase your tire temperature to levels that would affect your handling.

 

[byl]

The "ideal gas law" demonstrates to us the fact that the volume of a gas at a constant pressure is directly proportional to the temperature of the gas within its gaseous range. This would mean that any element which attains a gaseous state at a temperature below that of oxygen would gain less pressure as a result of a given increase in temperature (for the sake of example, we'll consider a temperature increase from 80deg F to 180deg F, or equally, an increase from 299.81K to 355.37K). Oxygen becomes a gas at 90.2K (Kelvin), increasing in volume (or increasing in pressure within a fixed volume) by a factor of .209, Nitrogen becomes a gas at 77.36K, increasing by a factor of .199, Helium becomes a gas at 4.22K (the lowest temperature for gaseous form in known elements), increasing by a factor of .158. Relating to the proposed situation at hand, logic would dictate that Nitrogen is superior to common air. Helium would be superior to either of the two.

The perfect gas low also and most importantly in our case state than every gas, every, behave the same way or closely enough to be assimilate to a perfect gas than any other gas:
PV=nRT, no mention of specific value for each gas.

 

[byl]

Nope, not inert. Not flammable maybe, but compressed air isn't going to be hazardous because of flammability.

Compressed air is hazardous because of the presence of O2 which can react with other compound
Nitrgen is an inert (commonly use in chemical industry to put reactor under a safe balnketing, arrrgghh you make me talk about work), meaning that it doesn't react, try to pput nitrogen in a contenair then a flame, nothung hapen. so not flamable and inert!