Hmmmm it's doing my nut in. Thought it might be the spacers, I've got a 35 mm kit as well on the back. The only thing i'm pretty sure it is, is the previous tracksuit wearing owner did the shocks. Dunno what brand, but it's a yellow and red cup kit so most likely gmaxx or something and more than likely knackered to boot. But obviously no bump stops built in on them. So guess it's just that