prolly the only way to figure out the weight to to take them to a service shop that does shocks also by the way they look you might have to take them anyway, but if they need serviced you will know right away as soon as you bottom out on every little thing. When they get serviced you can have them set up for the type of riding you do and how much you weigh. The best thing i can tell you is just put the bitches on hit a jump and if you hit hard they are f*cked if not leave them alone. If you want to aust them google it. I'm sure there is a web site somewhere that tells you how.