Well I got it sorted out.
I dont know how many of you use early SID's, but from the replys I got, prly not that many. Still, I will share my solution that worked.
I replaced the needle valve to schrader with the help of this site :
https://www.outsideoutfitters.com/ps-15 ... alves.aspx
bought the 28mm version: cap 99-08 SID (28mm + alum crown)
and the end result was this :
_________________1997 GT Zaskar
2014 GT Sensor Carbon PRO
2015 GT Grade alloy
"The nation which forgets its defenders will be itself forgotten"