Thanks DJ I have access to the nitro bottle I just need a standard starting place , my workshop manual does not say and modern thinking is 150 odd lbs,but this aint modern and I dont want to put too much in and I dont have allot of practise time available to go and test it so wanted to start standard and work from there. I have found out (dumb should have read book first ) that the adjuster does compression dampening and also effects rebound , not just rebound like I first thought .Cheers