do I really need nitrogen...

[zaneyzrex]

Rebuilt shocks couple Weeks back..had some minor leakage around bladder seal n needed adapters to get to the schrader valves..got some motion pro adapters n added 150psi w bicycle pump... My question is do I really need nitrogen for the riding I do ? Just backroad railing ..... no trackdays... (my roads are 35 miles of 15mph corners n switchbacks) shocks seem to be working excellent over the last 3days of railing over mingus (20 miles of corners) on the way home from work... Its cooler right now so that may help keep the heat down in the shocks..... So whats ur opinion on the subject ??

[skandix]

I have a friend who bought some gas filled shocks similar to our KYb for his HD, and for the last 2 riding seasons only filled them with air. No issues so far.

[btl68]

As far as I know, nitrogen is just more stable than regular air, so can't see why it wouldn't work, especially if you aren't railing on them on the track and if they leak a bit.

IMHO.

[zaneyzrex]

I have a friend who bought some gas filled shocks similar to our KYb for his HD, and for the last 2 riding seasons only filled them with air. No issues so far.

Only prob w ur reply is hes on n HD n ill put money hes not riding even remotely as fast in the corners as I am.... Lol
guess ill wait till im changing my rear tire at work before filling w nitrogen... Wont be long now that I actually have corners to ride....

[terryfulks]

As far as I know, nitrogen is just more stable than regular air, so can't see why it wouldn't work, especially if you aren't railing on them on the track and if they leak a bit.

IMHO.

+1
Nitrogen does not have the moisture of air, the moisture is what will expand with heat. Like with tires using nitrogen the pressure is more stable with less increase in pressure as heat increases.

[zrx24]

Nitrogen is also less prone to leaking through the bladder walls like air will do.

[zaneyzrex]

Nitrogen is also less prone to leaking through the bladder walls like air will do.

Thx all.... Guess ill try to get them filled this weekend before the ride....

[zaneyzrex]

Didnt get em filled w nitrogen but I did test them out today on white spars... New oil w 150psi of air n they worked awesome..very planted n stable... Only thing ive noticed is they work great on bumps if im railing along but are very harsh at slower speeds...
Still need to work on my zx9 fork settings n see if I can get them working better on the bumps...

[zrx24]

I've learned that 150psi is actually on the high side for pressure. I've found 100 psi seems to be the ticket, as suggested by several suspension tuners I've dealt with over the years.

[zaneyzrex]

I've learned that 150psi is actually on the high side for pressure. I've found 100 psi seems to be the ticket, as suggested by several suspension tuners I've dealt with over the years.

ok but whats ur weight n riding style ???

[vicariousrider]

Just a thought, but one thought that crosses my mind is the moisture, not so much for stability but more so because of corrosion. Not saying nitrogen inhibits corrosion, but the lack of moisture and oxygen will inhibit any possible corrosion.

That said, I think the material the gas chambers are made out of is aluminum, so the point may be moot anyway.

[compressor59]

Can you post up some pictures of the adapters and part numbers.

[zrx24]

ok but whats ur weight n riding style ???

Weight and riding style was never discussed with the regard to the amount of pressure needed to keep the oil from foaming or blowing out the seals.

[zaneyzrex]

Can you post up some pictures of the adapters and part numbers.

I have pics/#'s in my other threads on this page...

Weight and riding style was never discussed with the regard to the amount of pressure needed to keep the oil from foaming or blowing out the seals.

Ok but wouldnt the bladder pressure have an affect on how the shocks work ???

[zrx24]

I have pics/#'s in my other threads on this page...



Ok but wouldnt the bladder pressure have an affect on how the shocks work ???

Yes, and no. The pressure is not an adjustment mechanism like preload, or damping settings. The pressure needed for the shock to perform as designed is part of that design function.

The pressure in the reservoir is intended to limit fluid motion to minimize foaming, and to allow the damping components to work as intended. Too much pressure and the fluid won't work with the damping components, and you risk blowing out the shock seals. Too little pressure and the fluid pumps back and forth between the shock and reservoir, which results in foaming and does not allow the damping component to push through the fluid as needed to perform their task.

Generally the pressure of most shocks is around 150psi. Some motorcycle shock specs call for pressures as high as 200 psi, with many of those generally set in the 185psi range. Older shocks were designed to function at lower pressures, such as the old KYB design used on the ZRX.

Having had my shocks rebuilt many times with the thinking they were being pressurized to 150psi, I was shocked (pun intended ) to learn when I started asking around (Race Tech, my local shock guy, race suspension dudes) that the older KYB models called for around 100psi reservoir pressure.

Most here will just have them set at 150psi since that is pretty common these days for most shocks. But having run both 150psi and now 100psi, I can say that the shocks seem to perform better at the lower pressure setting. The higher pressure setting was more harsh, and I found that oil residue would be present at the compression adjuster knob. That leaking condition was not as prevalent at the lower pressure settings.



Dang it. I can't find the original model information on these KYBs that Lindemann and Race Tech provided when they looked up the specs for me. I'm sure somebody here knows that info. With that info you can look up the recommended pressure for these particular shocks, if you have the service manual available of course.





Well, that's what I've "learned" over the years having jacked around with these stock shocks trying to make them perform and in my efforts to extend the length of time between servicing. I'm sure others will be happy to chime in and share with us their experiences and preferences as well.

[zrx24]

Oh, I meant to post this up. A picture is worth a thousand words. Thanks to EA6BMECH (Scott) for his write-up in the suspension section on shock rebuilds. It was very helpful the first time I tore into my shocks.

[zaneyzrex]

Thx Zrx 24... Ill have to try 100psi when I get back on Sunday...

Have to start playing w the settings on my zx9 forks too...they dont like square edges...very harsh...