Oblique impact tests on bicycle helmets were used to validate Finite Element Analysis (FEA). Analysis of the forces acting on the `road' surface showed the helmet to have an effective friction coefficient on the road 0.2. The peak head rotational acceleration, < 6 krad s-2, was largely determined by the offset of the line of action of the normal impact force from the head centre of gravity. Oblique tests on frontal impact sites should be included in Standards.