In my article 'An analysis of Vincent Suspension' (MPH November and December 2021) I gave details of the ride heights of the Series A, B, C and D front suspensions, which I defined as the height of the top rear pivot axis above road level when the suspension was at null travel with a load of 232 pounds supported by the front forks. This loading is based upon the weight of a twin, with 40 pounds of petrol and oil on board with a rider weighing 200 pounds and a weight distribution of 42/58 (which was established by direct measurement). Obviously the ride height will change with different loadings. For the C Girdraulic the ride height is 34.7 inches, for the Series D it is 36.0 inches.
Norman kindly supplied me with dimensions of the John Emmanuel fork, which was analysed towards the end of the article. I decided not to quote the ride height for the JE fork because it is dependant upon the poundage of the springs fitted and the amount of packing which is placed in the springboxes. However for the two scenarios which Norman gave me, i.e. 30 ft/lb springs with 3 inches of packing and 45 ft/lb with 2 inches of packing, I calculated the ride heights to be 35.5 inches and 35.2 inches respectively. Obviously, these ride heights can be easily changed by altering the packing.