If lowering the preload does not work for you, as in the shock is too soft for weight and/or handling, modifying your seat may work, my B400 seat was modified by the previous owner and it works great for my wife (is supposed to be her scooter, even though I use it more
), the lady/previous owner said a custom "Harley seat shop" her husband uses, replaced part of the front seat foam with a thinner, but denser type and refitted cover, etc., is kind of flatter than oem, gives a better "rear end" support 
