the advice i was given from Denver Motorcycles (who knew everything you ever might need to know abiut srx's) was to lift the bike at the front by jacking under the headstock, such that the front wheel is off the ground and the forks are fully extended, then, fill up the legs to 120mm from the top (I use a strip of paper or card with 120mm marked on it, and use it as a dip stick) all you need to do now is select the viscosity of your oil.....i've been using 15, but i think 10 might be less bone jarring over potholes)