That is, within Lorentz invariance, force is not the same in all frames of reference, unlike Galilean invariance. But, from the earlier analysis based upon the Lorentz force law: γ γ F y = − − q γ γ v B , F y ′ = − − q γ γ v B , which agrees completely. So the force on the charge is not the same in both frames, but it transforms as expected according to relativity.