On the rear Olle shock there is a 2.5mm allen screw which I presume should be undone before turning the top nut to tighten the spring, however only a tiny part of the top nut is visible so how can one undo the allen screw with the airbox and silencer fitted so that adjustments of shock preload can be made and tried in practice sessions? Can the upper nut be tightened without loosening the allen srew?does the large lower nut have a function? Finally, what is the function of the lower left screw, which you advized to turn in 9 clicks, please?