Stock non-M arms are made from sheet metal that is merely spot welded together, which tends to flex and bend under moderate loads let alone track day or racing stresses. If you use grippier tires and an engine with more torque, then the stock arms aren't able to provide stability and consistent handling.
Fits: BMW M3 (E9X), BMW 1M (E82), BMW 135i/335i/535i (N54), BMW 335i/335is (N55). Confirm fitment with us before ordering.
