David's info is correct,in the early 70s Phil Irving told me the story of Henry who happens to be the gentleman opp page 19 Riders Handbook removing the front end.He was testing a Shadow with the newly fitted Girdraulic forks and whilst at high speed hit an Austin A30 which pulled out across the road.He hit the car amidships, with such force that it rolled and the impact ripped the steering column assy out of the UFM.Upon return to the works the forks were checked on a jig and found to be in perfect alignment.A tragic circumstance that illustrated the exceptional strength of the forks design.