First how much weight are you putting on it? Calculate weight of rider and passenger, stuff you are carrying, accessories fuel---then check operator manual for load capacity. Overload? No shock/spring combo will overcome that-----I believe critical is rear tire, in hot weather/overload/under inflation---weakest point. Hitting shocks on bump stops a usual sign of overload. Be Careful and overload = funny and dangerous handling in my book---Brake capacity? 2007 not new, lots of miles, not overloaded, shocks/springs done?