KX Riders
Maintenance & Technical => KX500 Original => Topic started by: hughes on December 24, 2004, 05:50:02 AM
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My brain is alittle clouded on what the nitrogen does for my rear shock. Here in a few days I will attempt to change the oil and have the bladder re-charged. What affects does different nitrogen pressures have on my shock :?: Because I was thinking of having my local shop fill the bladder to the highest spec. for my shock. I figure I could easy enough let some nitrogen out rather than put it back in. Thanks
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How much do you plan to have put in your shock bladder?
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Rick,
My Clymer manual say the spec. for nitrogen bladder is low side 142 psi.- high side 213 psi. I was going to let my dealer re-charge the bladder to at least 200 psi for a starting point.(easier to let some pressure out than put in back in). I started the disassembly of the shock this afternoon. I found zero nitrogen pressure in the bladder and very little oil in the shock. I would really like to know how the nitrogen effects or works with the shock. Thanks.
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Mainly it keeps the shock fluid under pressure to prevent foaming.
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In the perfect World, there would be NO air in your shock...just nice inert gasses, like Nitrogen. That's the design intent of the Bladder.
Manny
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Thanks Guys,
I do not how my rear shock was even working with no nitrogen or oil present. Can't wait to see how my bike rides and handle after I get done with is project. One Question. O.K if the nitrogen pressure keeps the oil under pressure to prevent foaming then the more nitrogen pressure in the bladder will effect the compression and rebound :?: Thanks .
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Not really, a liquid will only compress so far and the amount of pressure it takes to effect viscosity is ALOT more than than the shock body can hanlde.
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Thanks Paul.
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As a note, I run between 160-170 pounds of nitrogen.
Rick
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I will add this Nitrogen does not expand and contract due to heat like air. Also it does not condensate.
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Nice!!! I got my rear shock rebuilt this week and charge it to 160 psi of nitrogen and used 3wt. Bel-Ray HVI Suspenion fluid. Man it rides so go now :lol: Thanks Rick for your Sticky post about rear shock rebuilds. This was my first rebuild of a rear shock and everything went as planned. :lol:
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I will add this Nitrogen does not expand and contract due to heat like air. Also it does not condensate.
WRONG! Nitrogen expands and contracts due to heat just like air. In fact, air is 78% nitrogen. The reason shocks are charged with nitrogen instead of plain ole air is A) there will be no moisture present, B) the nitrogen will have a more CONSISTENT expansion rate than a mixture of nitrogen, oxygen, argon, CO2, etc (air), and C) nitrogen is a noble gas and will not react with the rubber bladder causing deterioration of said bladder.
Recall your basic chemistry......P=nRT/V. Pressure is equal to a constant (n) times rate of expansion (R) times temperature (T) divided by volume (V). As you can see the pressure of ANY gas is directly related to the temperature of the gas. Change the temp and you change the pressure.
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LOL sorry I would never remember any basic chemistry. I am just a guy that likes dirtbikes. I was telling of information that I have heard from other people. Also I am not really here to get peeps pissed off from my opinions. Nitrogen Gas = inert. BTW I will stick to my first comment. Because what you have said is exactly what I said. I just gave a basic oakie explanation.
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You were a little hard on Rowdy there!
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D**n, you guys are smart.... I know this... ME+Chemistry=Notad**nthing. Sure glad this site came up on my google search!!!!
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YIKES!!!! You guys forgot a key safety point! Oil + Pressure + Oxygen = Diesel Engine!!! One VERY important reason to use ONLY nitrogen to precharge the shock's blader accumulator is that nitrogen does not support combustion.