[Balky001]

I think at 20 stone the first thing you should do it get the forks revalved and re-sprung and rear shock resprung, if you don't want to shell out on a new shock. You could just have stiffer springs all round but the revalve will help with braking acceleration and smoothness of the ride. If you can afford it go for a new rear shock but make sure the supplier knows your weight so they can put the appropriate grade spring on it. Increasing pre-load only helps take the initial springyness out of the spring, once the spring is past the compression of the setting, pre-load doesn't have any affect, until on the way up again. Re-valve should help this.