Nitro in rear suspension... is this a must

[grabber_grabbs]

I did a stupid thing, i removed all the nitro from my rear suspension. Im new to this kind of thing and i should have read my shop manual before removing all the nitro from it. I thought i would make the ride more softer by removing the air (nitro) from it.

Stupid me, now i have to find a place where i can get nitrogen. My question is, can i substiture the nitro with air until i can find someone that can put some nitro in ?

[skip #7]

no under any circumstances use air,years ago when at yamaha school they had first generation mono shock that had air in it blowed it all to heck,what happened was the seal leaked a little oil into the air chamber,on compression it made like a diesel motor and ignited the oil and blew up,nitrogen dosen't burn hence it's use.

[grabber_grabbs]

no under any circumstances use air,years ago when at yamaha school they had first generation mono shock that had air in it blowed it all to heck,what happened was the seal leaked a little oil into the air chamber,on compression it made like a diesel motor and ignited the oil and blew up,nitrogen dosen't burn hence it's use.

Will i damage my suspension if i ride it without nitro in.... just trail riding

[dave34]

there is a disadvantage of using air instead of nitrogen to fill up your shock and that is not that it will blow up but you can get condensation in the reservoir since the shock heats up and cool down repeatedly. Nitorgen is used because it is an inert gas which has low expansion contraction qualities as well it does not support combustion. For short term use go ahead use air but it is best to go to some shock that has nitrogen, should'nt be charged more than 20 bucks to fill either.

[crf450319]

Wow, some pretty interesting stuff about using normal air here. I service my own suspension and brought my shock to my old suspension guy to have it re-charged with nitrogen. He told me that I could use air from a compressor if I had a compressor that would hit the appropriate psi. My compressor is only good for 100 psi, so I didn't use it.

This coming from a guy who owns a shop and has been in the suspension industry for 15 years.

If you're paying $20 for a re-charge your gettin' bent over the counter !! What you could do is find a compressed gas company in your area (if avail.) and rent a tank from them, you might have to buy a regulator which could be around $50 or so but then you're good for life.

If you're in a bind you can use air from a compressor, try to get the most psi out of it. Then when you can, have it re-charged with nitrogen.

[Maddog10]

My local shop was out of Nitro so i just used air in my 09. It's no problem, but i do recommend getting nitro back in it when they get some in. The only issue, according to the mechanics, is that the molecules in air are smaller than nitrogen, so it may VERY SLOWLY leak air out. Not enough to cause any damage for a while, but it may if you run the same air for a long period of time. I refilled with nitro, but yes, you can temporarily run air.

[busted bones]

The reason they use Nitro is the same reason they put it into car tires for a few more bucks now days, it doesnt heat up or cool down as quickly as regular air. This makes for a more consistent feel in the suspension

[DanielStickland]

My local shop was out of Nitro so i just used air in my 09. It's no problem, but i do recommend getting nitro back in it when they get some in. The only issue, according to the mechanics, is that the molecules in air are smaller than nitrogen, so it may VERY SLOWLY leak air out. Not enough to cause any damage for a while, but it may if you run the same air for a long period of time. I refilled with nitro, but yes, you can temporarily run air.

LOL the air doesnt leak out..... its as the expansion and contraction due to heat occurs, thus causing condensation from the Hydrogen atoms, thus reducing the density of the air in the chamber.

[willyd465]

i changed the fluids in my rm 125's shock and to recharge it i went up to belle tire since they advertise nitrogen inflation of their tires, got it where it needed to be for the cost of FREE!!! he even took me out to the shop and let me fill it myself so i know it was done right.

[surferchris1]

Dood, shop air will not make your shock become a diesel engine and combust (sounds like it was overfilled with oil and hydrolocked). Nitrogen technically doesn't heat up and cool down any faster or slower than normal air or leak out any faster (at least not to a degree that's relevant to this application, in fact the air we breath is about 78% nitrogen). Shop air doesn't ruin the shock body, (it's contained in a bladder, it never touches the shock body) However, I understand that the moisture in shop air is not great for the bladder.

DanielStrickland is on the right track but he got it a little backwards, the expansion and contraction of the molecules from heating up and cooling down doesn't cause condensation, it's the other way around. The condensation (which is already there, it came in with the shop air) causes the pressure in the shock to fluctuate with temperature.

The primary reason for nitrogen, is that it's dry. Yes, Nitrogen also has a low coefficient of thermal expansion, but mostly it doesn't have water (condensation) in it (which has a HUGE coefficient of thermal expansion) which means it get's hot and expands which builds pressure within the shock and changes your suspension characteristics. The other reasons it is well suited for this use is that it's non-flammable, non-corrosive, non-toxic and dirt cheap. (I pay around $32 to fill my 175 cu. ft. tank)

Shop air has lot's of condensation in it, but I doubt many of us would notice it's effects while riding, it's perfectly acceptable in the short term. As for any long term damage I can't say for sure, I'd recommend filling with Nitrogen just for the sake of doing it right.

A note about nitrogen in tires, it has it's benefit's (no matter how negligible I think they may be), but I will say this. The primary goal is lack of condensation, so if your tire guy is sloppy with the lube and drips a few drops into the tire, (which we all do, I busted tires for a couple summers back in high school) he just negated any benefits attributed to the nitrogen he filled your tires with. Just something to think about.

[Steven D]

My local shop was out of Nitro so i just used air in my 09. It's no problem, but i do recommend getting nitro back in it when they get some in. The only issue, according to the mechanics, is that the molecules in air are smaller than nitrogen, so it may VERY SLOWLY leak air out. Not enough to cause any damage for a while, but it may if you run the same air for a long period of time. I refilled with nitro, but yes, you can temporarily run air.

Air is 78% nitrogen 21% oxygen and 1% argon and carbon dioxide.

Nitrogen and Oxygen are atoms not molecules and have two electron shells, so they're bout the same size, argon has three, and carbon dioxide is a molecule about three times the size of nitrogen.

LOL the air doesnt leak out..... its as the expansion and contraction due to heat occurs, thus causing condensation from the Hydrogen atoms, thus reducing the density of the air in the chamber.

Shock shaft movement is the primary force regulating bladder volume, by displacing the fluid into the nitrogen chamber. Temperature creates a very small change as it heats/expands the shock fluid.

Condensation results when the temperature/dew point spread approaches zero and water vapour present in a given air mass condenses to form a liquid. It could only occur after the shock has cooled.

The only Hydrogen atoms that could have anything to do with this are the ones present in the water(H20).

Condensation of any water vapour present will lower the pressure not the density.

[Steven D]

Dood, shop air will not make your shock become a diesel engine and combust

I won't become an engine but the combustion is possible. Temperature increases with pressure, if the shock fluid had a low flash point and the shock was hot already it could happen near full compression with a failed bladder.

[honda88]

Get your own nitro setup, I have one. You need regulator tank which I got one when I got nitro from a gas company(not fuel gas,lol). cost 225.00 for entire tank,regulator,hose and air chuck.air chuck is easier than a schrader valve. Cost to fill tank when empty well I had tank for 4 years now but they said 10 bucks and tank will do well over 1000 shocks. I used to get charged from stealership 20 bucks a charge. cost them pennies. Shock only takes 147-149 psi.

[Maddog10]

LOL the air doesnt leak out..... its as the expansion and contraction due to heat occurs, thus causing condensation from the Hydrogen atoms, thus reducing the density of the air in the chamber.

I didn't get technical with them. They just told me that it would slowly lose air. I ran air for about 5 days till they got nitro in and then replaced it.

[thak]

hello,

this air versus nitrogen topic is very interesting!, I also have been wondering what is the difference but haven't noticed any. I service my shock about 5-10 times per year and earlier used to use 15bar nitrogen to fill shock, but now last 3 years, I used just 8bar air from home compressor. Still servicing shock at least 5 times per year, and I cannot say any difference to earlier 15bar nitrogen.

My feeling is that nitrogen is usefull mainly when we talk about 2-3 or more years between shock services, and maybe some top level MXers can notice difference...which I'm not, at least not yet ?