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9/22/2015
Location
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Edited Date/Time
2/8/2016 6:25am
As anyone heard any news on the new factory hybrid showa forks. I saw Steve from racer x mention something about them in an article. One leg of the fork uses an air chamber. The other side uses a coil spring. Apparently js7 and bb4 really like it. Is Weimer running this fork as well?
And, if you are sidelined by injury for a time while technology is running away ,coming back and climbing on a totally new design could cause another crash.
The Shop
So... Half a 2011 cr250 fork and half a new one?
I cant see why anyone would not be using Nitrogen is their forks.
After all rear shock bladders have been using Nitrogen for yeeeears...
Here is South Africa we have buy the Nitrogen but never own the bottle. We pay a deposit on the bottle.
Nitrogen ain't cheap either. .especially here in SA.
It consists of the original KYB PSF1 on the left and a KYB spring fork on the right using a YZ450 cartridge and everything matched up for correct length and travel.
In the spring fork I used a stiffer spring than normal for my weight so that the pressure in the air fork could be reduced to lessen the top out/preload effect associated with air and give me some adjustability for conditions as well.
Ken Wheeler
Factory Spec Suspension
The big problem with air is moisture. If you use a filter/dryer on your compressor, then moisture should not be problem. The aircraft industry uses nitrogen in landing struts because of the moisture. But that is because flying through -30C temps in the flight levels numerous times a day freezes the strut. Not because they need stability.
One other question...if an airfork is gulping air during the moto and pressurizing....won't it do the same with nitrogen? Gulping air is a seal problem, not the species of gas in the chamber.
Moisture is an issue in compressed air but not so much with suspension because of the volume differences. Think about how much air goes through a compressor and is stored in there.
Nitrogen is also used in the tires of planes to stop pressure fluctuations with air pressures and heat levels. Think about a plane at altitude where it's freaking cold as, then it comes down to land, the tires hit the run way and skid due to not spinning v's velocity of the plane, so the the temperature increase is very sudden and high. It's why they also use nitrogen in car race tires to control pressure fluctuations, and now offer it to you for your family car at ridiculous mark up in price. Nitrogen is cheap, the bottle hire is not.
There is no gulping, eating or slurping. Only splurging.
Just an edit note. DO NOT FILL YOUR SHOCK BODY WITH COMPRESSED AIR FOR POSSIBILITY OF EXPLOSION AS THE AIR EXPANDS WITH HEAT FURTHER THEN THE DESIGNED NATURE OF DESIGN STRENGTH
And a lot of the big teams do use nitrogen instead of air but the pressure still builds as the race goes on
The pressure will still increase with nitrogen in a shock, air fork, or tire it just increases in a much more consistent fashion. There was a couple of times this past year where F1 teams got into trouble because tire pressures were to low at the start of the race. The premise was the team under inflated the tire to allow it to be more in its "sweet spot" pressure when the tire was at race temp. Back in the mid 2000's Ferrari was running refrigerant in there tires to keep tires cooler and more consistent over the distance between pit stops.
Its the moisture content within most peoples compressed air that causes big issue. If you use scuba air, you will find the expansion rate (or in the case of a finite volume such as a shock) the pressure rise between compressed air and nitrogen nearly identical with temperature rise. And yes this has been tested in shocks in use on bikes with data logging.
The glaring negative to compressed air vs nitrogen is the oxygen content. Oxygen in some systems can cause headaches with corrosion and reactivity. In the ultra rare case temperatures are near ignition temperatures of an oil... And a quick leak combined with a spark event could cause a disaster. Compressed air is more dangerous than many know when it comes to fire risk. All in all for many people nitrogen is easy to get in a pure form and makes things easier than knowing if your compressed air really is water free.
Pit Row
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