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Shock reservoir valve location?
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Posted by: RM_guy---------------------
Should the shrader (sp?) valve on my shock reservoir be pointing towards the pipe mounting bracket as shown in the attached picture? It doesn’t hit but it sure does come close, especially when I bounce on the seat. I thought it was suppose to be pointing straight back. I never noticed it being this close before I sent it to Jeremy for a re-valve but I don’t think that they would have removed the end of the reservoir during the re-valve. It may have been that way from the beginning as far as I know.
Is this the position of the valve on anyone else’s ‘01RM250?
Thanks
Posted by: KawieKX125---------------------
I am pretty positive that he would put the valve in the same location as when he removed tha bladder to dissasemble the shock and change the oil. If it never hits, but comes close, you should be fine. The only thing that I would be worried about is that the pipe would heat up the nitroget in the bladder, but on almost all bikes, the bladder is in a similar location.
Don't worry about in too much IMO.
Posted by: Papakeith---------------------
Isn't the point of using nitrogen the fact that it is an inert gas and is not affected by temperature increases?
Posted by: mxneagle---------------------
Nitrogen is an inert gas alright but it still has to live up to the ideal gas law...
pv=nrt, considering the nitrogen in the resevoir will always have the same number of atoms and is restricted to the same volume, the equation of importance is p1*t1 = p2*t2. This means that as you heat up the gas the pressure increases. The only reason that nitrogen is better than plain old compressed air is that it is dry (lacking water vapor)
Posted by: Vic---------------------
Quote:
Originally posted by mxneagle
The only reason that nitrogen is better than plain old compressed air is that it is dry (lacking water vapor)
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And why wouldn't we want any water vapor in there?
Posted by: mxneagle---------------------
My only guess is that it would cause a greater pressure rise. Why you ask...because the water will go thru a phase change (liquid to gas) as the shock heats up (they get well over the boiling point of water) and that essentially adds more gas molecules to the volume. Kind of like a steam bomb.
Posted by: Vic---------------------
Quote:
Originally posted by mxneagle
My only guess is that it would cause a greater pressure rise.
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That's my thinking, too. I've been told it's because the water will cause corrosion, but I don't see that as a problem with a rubber bladder.
I would think that dry air would be an acceptable alternative to nitrogen.
Posted by: steve125---------------------
RM-Guy, it would be a good idea to move the schrader valve away from your pipe bracket. Since the bladder cap is held in by a circlip,it can be rotated around 360 degrees. I'm sure if your carefull you can rotate the cap (just slightly) even though the shock is under pressure. I know it rotates easily when there's no pressure. The problem here is when the upper shock bushing begins to wear , the valve will hit the pipe bracket and then guess what can happen! Either way the valve (bladder cap) is in the wrong position and it needs to be moved.
Posted by: RM_guy---------------------
Thanks Steve. I did try to move it under pressure but it wouldn't budge. I can release the pressure and have my local shop charge it back up.
Posted by: Chief---------------------
Hi RM_GUY,
Your pic isn't showing up for me. Here is one of mine. It does point straight back,
Chief
http://photos.yahoo.com/bc/chiefcam...lve.jpg&.src=ph
Posted by: Chief---------------------
Yea, now that I see your pic, It looks like you have to reposition it. 
.
On the bright side, Good that you noticed it before anything happened.
Chief
Posted by: RM_guy---------------------
Well I called Jeremy to ask if it was even possible to turn the valve to relolcate the valve under pressure. He said it turns pretty easy. My problem the first time I tried to turn it was I couldn't get a good enough bite on it to turn it. I ended up usung a pair of channel locks with an old inner tube under the jaws. Presto It turned with no problem and no marring on the shock body.
Thanks for everyones help
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