Measuring rear suspension static sag

[Mark]

Hi all,

I know the theory about the weight of bike plus rider should use up about one third of suspension travel, and to check this you should measure between a point on the frame and one below it on the swing arm with A) bike supported so that the back wheel is off the ground, and B) with the rear shock fully compressed. Take one reading from the other and that is the range of travel, you want to use up a third of it as static sag.

My question is has anyone got a method that they have used to sucessfully compres the rear shock?

I have contemplated removing the saddle and using a ratchet strap between the swing arm and rear of the frame - could this damage the frame?

Thanks for your thoughts

Mark