Upgrade to enjoy this feature!
Vital MX fantasy is free to play, but Premium users receive great benefits. Premium benefits include:
- View and download rider stats
- Pick trends
- Create a private league
- And more!
Only $10 for all 2026 SX, MX, and SMX series.
The air you breath is 80% nitrogen. Why is nitrogen used? It’s easy to carry around a pressurized tank to 2000psi as another person suggested, it’s cheap, and it lasts along time. Yes, being inert has a good quality.
Compressed air works perfectly in your bladder or piston shock. No ifs ands or buts.. it expands and contracts the same under heat, your gas WONT leak out.. no worry about aeration, and it’s Contained in a rubber bladder, you have no worry about corrosion. Nitrogen was originally used because of the Air Force, it was cheap. Compressed air with minute quantities of moisture would freeze in accumulators at altitude. Oil does have a water content itself most people don’t realize, which is why a certain oil manufacturer that factory fills Wind Mills bought a dehydrator to reduce water content of oil. I’ve ALWAYS want to dehydrate a shock oil to see if it would reduce fade for a gnarly pro like Carmichael, but it’s the heat And sheering that destroys the VI in the oil very rapidly. Don’t worry about Nitrogen, after 30 minutes on a shock dyno with a high VI shock oil (400+) the oil loses 50% of its original viscosity. That’s insane.
Your tire or shock with ANY gas will expand exactly the same with temperature increase, as compressed air. Great you tube video on Ferrari testing tires with different gases and heating them to the moon, then track testing. They came to the conclusion it’s irrelevant.
I’ve used compressed air my entire life in my shock, I’ve also used Argon and Nitrogen as well. It would be interesting to charge a shock with refrigerant, as the static bladder at 150 psi were compressed, it would remain much closer to the same instead of increasing to 300psi as the shock is fully compressed. Decker said he tested different gases at Kawasaki and could not feel a difference but he COULD feel a difference in different air pressures and how they tried valve around it for James Stewart. So that must be the way OEM settled at the shock pressure they have..
The Shop
DeCal Works Huge Plastic Inventory of UFO and Polisport kits.
Luxon 4-Post Bar Mounts
$189.95 - $239.95
Free shipping: VITALMX
There is no SAE rating for shock oils. Numbers are arbitrary and irrelevant. Motuls 5wt can be Honda’s 10wt. Which is why some say light, medium and heavy. 10wt doesn’t mean anything in the shock world. So when you change your shock oil, check this chart out. There are tons out there.. make sure you know what you are buying
If you had to use air you could, but i would do it in areas of low humidity. As someone already stated, our air is 80% nitrogen.
I use the riders weight to regulate what pressure to put in the shock.
This is the fitting that needs to be used so you do lot loose 20-30 psi when you pull the air chuck away.
You won’t lose air remove the chuck or needle. Only checking or inserting, the bladder volume is very small..
Here is another great test of expansion:
https://youtu.be/kmnZ4-EUbIk
I doubt people are charging their suspension or tires with pure O2, which would not be a great idea given how aggressively reactive pure O2 is.
All gases (nitrogen, oxygen, air, water vapour) expand at the same rate. Been scientifically proven countless times.
Bottled nitrogen contains no water vapour because of the way it’s produced, not because of any inherent property of nitrogen. If I wanted to be that particular about moisture in the gas I could make compressed air with no moisture just as easily.
As far as permeability goes, air is 80% nitrogen anyway (actually about 79%). If it was just the oxygen permeating the tube/tyre, we could get pretty close to pure nitrogen by just filling the tube with air, then letting all the oxygen disappear by itself. Makes you wonder why they bother with those expensive pressure swing and cryogenic plants to make pure nitrogen...
We do need nitrogen to make oil. Also steel, and ammonia.
There are people that think Anti-freeze cools a motor when it has no latent purpose aside lubrication, corrosion and freezing. 100% water Cools best and does all the work. They also think wind chill affects their motorcycle or car... heck, they even think the planet is ending in 11 years because of climate change 😂 Lots of misunderstandings and myths out there, and even with the planet ready to spontaneous combust 🌞 because of CO2, they will still mix their bike 32:1 without regard to our precious planet. God damn plastic straws, don’t get me started
Stick with what works....
Pit Row
Nitrogen v Oxygen
Villopoto v Dungey
Stewart v Anybody
2 stroke v 4 stroke
Oil-Gas premix ratio
MXGP v Anything else
Day v Night
Big boobs v Small Boobs
Anything about JLaw
.....
shifting with clutch vs. no clutch
cheap oil vs expensive oil
AV gas vs pump gas
FYI. I am from Louisiana and had the most wet air you could possibly have (besides actual rain) inside my forks and probably shock without an issue or difference in feeling ever.
Doing a shock service today and pondered a bit - Recalled this thread from yesteryear funnily enough.
Seems Suzuki was happy to recommend refilling the shock on their 250 in 2006, using our globally available 79% mix. Don’t think gas laws have changed much since then. Todays shock will be getting air!
If you’re a hack job go ahead and use air.
Or do it the right way and use Nitrogen.
Stop cutting corners. Hopefully if you’re using air it’s for your own shock and not someone else’s.
Haha I always bitch about what a scam nitrogen in tires is. Makes exactly 0% difference for street cars.
However I can see some very slight benefit for extreme uses (like racing). Buddy earlier talked about how all gases expand the same and it's been tested, and that is kinda true. Most gases follow the ideal gas law at low temperatures and pressures. But once we increase those, the gases do start behaving slightly different because things like the interaction of individual molecules become meaningful. So a shock at 150-200psi and what, 80 degrees Celsius would start to deviate from the ideal gas law.
So for a use like a shock, using nitrogen vs air could provide maybe fractionally better consistency from cold to hot performance. Like maybe. 25% or .5%? Very tiny benefit, but race teams are obviously looking for every tiny benefit they can find, so it's worth it for the predicability.
Being our natural environment is 78.2% nitrogen……
Post a reply to: Nitrogen myths