Suspension heating up?

[KarlP]

It is my opinion, and only my opinion, that using nitrogen is just plain easier and more consistent for the OEM and anybody who charges more than the occasional shock.
I read all the arguments pro and con. Uh-huh....some of it is really stretching. Some of it is pure BS- nitrogen better not be an inert gas, for example.

A standard high pressure cylinder of nitrogen with a regulator will charge a LOT of shocks with no fuss or trouble.

We build a system here at work that is used to boost nitrogen pressures to 550 psig for laser cutting tables. We sold one to an Air Force contractor who is using it to fill aircraft tires. He used to use high pressure bottles, but it took 5 or 6 to fill a single tire. I asked him about the use of nitrogen for tires and he stated that it was an Air Force requirement. (Big Help)
He stated that he was aware of high pressure air compressor sytems sold for testing purposes and he pointed out that they seemed maintenance intensive, energy hungry, and physically large. Our system seemed like just the ticket to him.

The point is a lot of factors go into picking the right tool for the job at hand. Those factors can result in some strange stories on the innernet

[scheckaet]

Some of it is pure BS- nitrogen better not be an inert gas, for example.

wiki explain it better than I could:

Nitrogen gas has a wide variety of applications, including serving as an inert replacement for air where oxidation is undesirable;

To preserve the freshness of packaged or bulk foods (by delaying rancidity and other forms of oxidative damage)
Use in military aircraft fuel systems to reduce fire hazard, see inerting system
Filling automotive and aircraft tires[7] due to its inertness and lack of moisture or oxidative qualities, as opposed to air, though this is not necessary for consumer automobiles.[8][9]

Nitrogen molecules are less likely to escape from the inside of a tire compared with the traditional air mixture used. Air consists mostly of nitrogen and oxygen. Nitrogen molecules have a larger effective diameter than oxygen molecules and therefore diffuse through porous substances more slowly.[10]

[KarlP]

Yeah, ain't the innernet a cool place? One can find anything.

when inert is used to mean non-oxidizing, all is well.

When inert is meant to mean non-reacting it is applying only to the noble gasses. In the gas industry we don't refer to nitrogen as an inert gas because it isn't one. It reacts with all kinds of things to make other things.

As far as rates of diffusion..........Sheesh, seems far more likely to use a tank of nitrogen to charge a shock 'cause it is a hell of a lot easier and cleaner than a compressor.

[canyncarvr]

...didn't see KarlP's post when I started this one.....

For the record:


inert gas: A gas that does not react chemically with other substances coming in contact with it. Also referred to as noble or rare gases, inert gases include neon, argon, helium, krypton and xenon.

http://www.signcrafters.com/resources/g ... ary_item=I

Nitrogen?

It is commonly thought of and used as an inert gas; but it is not truly inert. It forms nitric oxide and nitrogen dioxide with oxygen, ammonia with hydrogen, and nitrogen sulfide with sulfur.

http://www.uigi.com/nitrogen.html


Try sucking on the end of a spa ozonator hose if you think nitrogen is inert!!

Strictly speaking, while it may be used AS an 'inert replacement', it is NOT inert. It can be used AS an inert replacement for tire inflation 'cuz there is nothing IN the tire for it to ERT with.



Something to keep in mind: Wiki stuff comes from the general public. Sometimes it is monitored/vetted fairly well..sometimes not. The wiki input in this case isn't wrong as long as you stick strictly to correct grammar...the '..used AS an inert replacement...' part.

I have a few things on my list of 'stuff' to own someday. A couple got knocked off recently (a pressure washer..!THANKS HONEY!...an HF tire changer) and one maybe not TOO far off in the distant future is a nitrogen tank with a regulator!!

[scheckaet]

when inert is used to mean non-oxidizing, all is well.
As far as rates of diffusion..........Sheesh, seems far more likely to use a tank of nitrogen to charge a shock 'cause it is a hell of a lot easier and cleaner than a compressor.

Yep and yup thanks for the clarification there

[Jeb]

For the purposes of the topic nitrogen can be thought of as an inert gas. In fact, while technically it doesn't fall under the "truly inert" category like a noble gas, nitrogen provides a very reliable inert atmosphere. Only under very high temps and exotic and expensive catalyst can you make nitrogen react.

It's so inert that if you breathe elevated concentrations of it, the hemoglobin in your blood cells will become "inerted" and you will die from asphyxiation unless removed from that atmosphere (and even then you could die or suffer dain bramage).

A BTW and quite possibly a useless piece of trivia for most: the two compounds that are responsible for the most fatalities in manufacturing/industry are hot water (high heat capacity, causes severe burns) and nitrogen (asphyxiation). Why? Because neither are regarded with the same respect as other more "dangerous" compounds because "gee it's only water" and "nitrogen is inert so it can't hurt me"

Sorry for the hijack!

[canyncarvr]

Only under very high temps and exotic and expensive catalyst can you make nitrogen react.

..or in a corona under ambient temps and a plain, cheap 'catalyst' like moving air.



Hence the 'suck on an ozonator' comment.


So...does this all mean it's time to go shopping for a bottle full of the stuff and a regulator equpped with a no-loss valve?

[Colorado Mike]

Good point on the dangers of nitrogen, Jeb.

Reminds me of my earlier work in the field of nuclear physics (nookular if you're from Crawford). I was involved in development of the Nitrogen bomb. Similar to the neutron bomb which kills by radiation and leaves cities standing, the nitrogen bomb only kills those with bramaged dains. Progress was going well until funding was cut by the Dumbocrats on fears of a waning constituancy.

[KarlP]

"So...does this all mean it's time to go shopping for a bottle full of the stuff and a regulator equpped with a no-loss valve?"

Not at all......unless you want to charge a shock with it.

I realized something during further research on the original topic for this post: It is time to get the fluid changed in my shock!

At first I was thinking that at about 30 to 45 minutes into a ride the shock was heating up to the point that it wasn't working as well anymore. The heating up part can't be so.
At 10 minutes it is warmed up to proper operating temperature. I can feel that plain as day. From 10 minutes to 30 minutes it may get a bit hotter, but not much. It can't, and it doesn't feel like it is by touch. Definately not enough to change the VI of shock fluid, the gas pressure in the shock has already risen, etc.
I think what is really happening is that from 10 to 45 minutes I've got plenty of juice. After that I'm looking for a reason to take a break!

[KarlP]

I sent my shock off, got it back, and it is just like slipping on a new pair of shoes.

aaaaaaaHHHHHH. Very nice.

Interesting observation- The previous shock set up seemed to have very little damping when you pushed the seat down by hand. I'm sure it did have some reasonable damping when on the trail because it wasn't that bad. The new set up is positively stiff. You can't push it down with any speed, you can hear the damping as it rebounds. I'm still playing with clickers and trying to get the front/rear to cooperate. It is much better.

Cool beans!

[canyncarvr]

I don't recall..and only breezed through earlier posts..but, sent it to whom?

Was any revalve part of it? Even so, you should expect the observed 'stiffness' to indeed be resolved (or at least changeable) with the clickers.

Anxious to hear how it works all het up!

You sent it off with the spring off, I presume? So...you put the spring back to the same physical position? It's not 'stiff' 'cuz the preloaders are cranked down, right?

Sorry...you know all that stuff. It just occurred to me is all..........

Thanks for an update!!

[kawagumby]

Someone said something about gases not reacting with anything in an empty tire...but what about the tire itself? Every tire compound is somewhat different with regard to molecular stability and friability (I guess that's a word).

Karl, when I first started changing the oil in my shocks (I've had my own nitrogen bottle since 1980 or so, and it's still got original gas in it!), the first thing I noticed was that the stock shock oil after just one season was pretty thin and stinky. I remember someone telling me that the japanese were using fish oils rather than petroleum based oils in the shocks, perhaps one reason for the rapid decline of viscosity. Even with the newer bikes, I've noticed a simple oil change is like revalving for more damping. It works wonders!

I just bought a WR250R, the yamaha dual sport, and it doesn't have enough shock rebound damping (it's close but no cigar), I'm thinking about just sticking some high quality oil in it to see if that's all it needs.

[KarlP]

I didn't mention who I sent it to. If it continues to work this well and I can get the last of the clicker tuning done I'll give the outfit a plug. So far all I want to say is that the service was very nicely done.

The valving was changed and I did have to re set the spring preload. I've been doing spring preload in a kind of wierd way. I'll set it "by the book" as close as I can get it but leave the locking collar loose. I'll go run a bit of a loop and see if it turns O.K. and the front/back "attitude" feels right. If it doesn't, I'll stop and lay the bike down and turn the spring to adjust preload. It is usually not a very big adjustment but makes all the difference in this frame.