Originally Posted by Mark
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.
Mark, sag is measured from the axle to a point vertically above it - subframe.
First you measure this distance withe the bike on its stand or with the rear wheel off the ground. Then with the shock on its standard setting, stand it on its wheels, sit on it and bounce up and down a couple of times. You should be sat with your feet on the pegs, hands on bars and then measure the distance again. This will give you your sag measurement. You need a couple of helpers to do this.
Each bike/shock will have its own sag measurement. Lets say its 50mm You adjust your shock spring to give you that distance. You should adjust the sag to be the same with you and your load on the bike.
Some bikes have a three position spring adjuster to achieve this but is doesn't give you much control. Thats where the Ohlins/Wilbers come in. They have a threaded adjustment to give you a bigger adjustment range and you can get a spring that will suit your weight range.
Taking a 3rd of your total shock travel wont hack it. Most rear springs are progressive these days.
Once set, you can play with compression and rebound
Nostradamus Ate My Hamster
Last edited by Redboots; 8 May 2008 at 21:09.