Shock Rebuild?

5 replies to this topic
  • tpars121

Posted January 14, 2011 - 08:04 AM


I am rebuilding my shock with the SPI kit using their instructions and it says to fill the bladder with nitrogen and release a few times during the process. Can I use air for this part? I plan to get it charged with nitrogen when I'm done.

  • crf450319

Posted January 14, 2011 - 09:21 AM


I'm guessing the reason they want you to fill/release with nitrogen a few times is to purge all of the air from the bladder, so the last time you fill it there's nothing but pure nitrogen in the baldder.

I just got my own nitrogen tank (a pain in the ass if you don't want to be on the rental program) and I'd consider doing what you're talking about. But up until now I've always filled the bladder with air from my compressor and then taken it to a shop, released the air and had them fill it with nitrogen.

Will purging all of the air out of the bladder make a difference ? I don't know, and I don't know if I'd ever be able to tell the difference in feel but maybe someone has done some testing and found that there is indeed a difference ?

  • grayracer513

Posted January 14, 2011 - 09:36 AM


No, you can't use air. The poster above is exactly right in that this part of the process is intended to purge the air from the bladder and replace it with nitrogen.

At this point you should have already bled the shock and b e ready to fill it, so if you have no nitrogen fill setup of your own, take it to a shop and have them purge the air and fill it to your desired pressure. Refer to the chart Dave sent for the pressure to use for your application. If you did everything right, you are going to love the shock, BTW

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  • tpars121

Posted January 14, 2011 - 10:49 AM


This is the part of the instructions I am talking about, steps 1 and 9:

1. Mount the top of shock body into a holding device or vice (the compression adjustor remains out) and install the bladder. Note that you may have to fill the bladder with a small amount of nitrogen to keep the bladder in a non-collapsed state. Install the metal ring and pull the bladder cap up into position and reposition the valve to the stamp marking made earlier.

9. With the shock still in the clamp and in this position, charge the bladder with about 20PSI of nitrogen.

  • grayracer513

Posted January 14, 2011 - 11:01 AM


Yes, you can use air in place of nitrogen all the way through until step 25.

  • tpars121

Posted January 14, 2011 - 11:04 AM


Yes, you can use air in place of nitrogen all the way through until step 25.

Thanks Gray.
I got all of my parts from Dave and I'm trying to read thru the instructions before I start installing.

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