Air shock pressure?

[Swoosebag]

I have a set of rear air shocks that came on the bike when I bought it. There aren't any markings on them that I can find. Any one know what kind of air pressure I should run in them?

 

[satariel666]

Normaly nitrogen pressure in a single motorcycle rear shock is estimated at
14 BAR at maxiumum. With no name shock I would try 10 BAR or so as a good
point to start.

 

[Fire-medic]

I am not a suspension expert.

I am assuming someone threw-on some H-D, or maybe Kawasaki shocks, I think those two ran 'em on their touring models. You could do yourself a favor by posting pics, maybe someone will recognize 'em. You could always air them up to about whatever makes them extend, and then bump 'em by 5-10 psi increments until they became rigid struts-"too-much air!" and then you should bleed 'em off of-course.

To my knowledge, pressures for nitrogen-charged shocks aren't what you would expect to run for atmospheric-air charged shocks. Ten bar is 145 psi, fourteen bar is 203 psi, which is I believe, 'way-too-much for what you probably have.

 

[Rusty McNeil]

To my knowledge, pressures for nitrogen-charged shocks aren't what you would expect to run for atmospheric-air charged shocks. Ten bar is 145 psi, fourteen bar is 203 psi, which is I believe, 'way-too-much for what you probably have.

+1,

They aren't so different than air shocks on a truck. The air is really only supplemental.

Not knowing these particular shocks I'd guess 30 psi, or two bar, might even be past the limit.

I'd suggest letting all the air out of them, ride it and add air as needed till it feels right.

 

[satariel666]

Do not ever use air in high pressure schocks,never.

I use to service some single shocks from motorcycles and i cant even recal ONE with preasure bellow 10 bar...i used argonium as i do not have nitrogen on hand.

Over 10 bar of air and oil may couse a diesel effect and your schocks can explode.
If your rear schock has reservior then like 99% of them it has a diaphram inside to prevent diesel effect.

Do not mix air pump forks and high pressure rear schocks.
You can always call or visit racetech website for proper infos. Air schocks from trucks completly differ.

 

[Rusty McNeil]

Do not ever use air in high pressure schocks,never.

I use to service some single shocks from motorcycles and i cant even recal ONE with preasure bellow 10 bar...i used argonium as i do not have nitrogen on hand.

Over 10 bar of air and oil may couse a diesel effect and your schocks can explode.
If your rear schock has reservior then like 99% of them it has a diaphram inside to prevent diesel effect.

Do not mix air pump forks and high pressure rear schocks.
You can always call or visit racetech website for proper infos. Air schocks from trucks completly differ.

+1 on not using air in high pressure shocks. Those are meant to be charged with gas. Typically found on single tube applications like sport bikes, dirt bikes, ATV's etc...

Motorcycle "Air shocks" like those used on Harley's and the like, are composed of the typical shock components.
Spring inside (instead of outside like normal motorcycle shock)
Oil
And a moving orifice attached to a rod for the oil to flow through to provide damping effect

Add an air space, diaphragm or seal of some sort to separate the oil and air and an air valve to add air, then you have an air shock.
These are NOT high pressure devices. And are typically not high performance shocks. Some of the cheapest don't even separate the oil and air and are a horrible design.

When referring to a "truck" I may have misled, What I mean there by the truck application is the after market shocks that can be bought at most auto parts houses for 1/2, 3/4, and 1 ton pickups, not commercial tractor trailer rigs.

These are typically used to compensate for extra tongue weight for pulling and hauling, or the addition of camper shells and service bodies to these vehicles.

Their construction is identical to the first description of a motorcycle air shock, except there may or may not be a spring inside as found in stock H-D air shocks. But damping and air system are the same operating principle.
There are some truck air shocks shocks that are not "air only" and have a helper spring on the outside. This is an option.
Whether "truck shocks" are bought with or without the coil over option they are still the same in operating principle as far as damping goes.

Principle in all air shocks is basically same, they are low pressure devices, and not to be confused with high pressure gas charged shocks.

Air bag systems are a whole different animal altogether. They may "look" like air shocks but Depending on design they typically will not have ANY oil damping system. And never have a spring, inside or outside.