Reply To: Rock Shox bottoming out on top of the tire, help needed


Thanks guys for your help. This 1990’s Rock Shock Mag 20 only takes 35-48lbs of air. I’ve read that most fill this shock with a basketball type fill needle rounded at the fill end so as not to damage the seal. Please explain how a suspension specific pump will help in this situation, will the fill hose even fit this older type fitting? My problem seems to be that I am unable to replace the very small fill screw, about 1/8" diameter, before the air pressure drops to about 25 PSI, even though I inflate the shock to about 60 PSI. The air rushes out so fast after I remove the fill needle. I do not want to bust the seal by over inflating. May be there is a better technique to replace the fill screw without losing so much air pressure? I’ll try removing the needle and then covering the air inlet with a finger while trying to replace the air inlet screw.
I’m glad to read that what I’m experiencing is normal. I think I just need to develop the technique for filling the shock without losing so much air pressure, or maybe there is a better way?
All suggestions are appreciated.

I appreciate your help and comments.