so i have 2 set of wheel for my x5, in winter i have the fat tire 18 inch wheel, the car is doing great no issue, but in summer i put my stagger 20' 4.8is wheel with the slim tire ... and the car shake/bounce from right to left every time i hit a bump/road imperfection etc, its really hard to keep the car in control ... but no problem when the road is flat ... the problem is it the shock absorber ?

__________________
BMW X5 3.0i 2006