Instruction Sheet No. 3, the Vincent Gearbox, under 'Stiff Gearchange' states
"This may occur if the pivot bearing plate G50 is bent inwards, because then the actuating arm pivot G68, which is screwed into the plate, is pulled out of line with the bush G75 in the cover. One symptom is the presence of a small gap between the cover and plate just below the footrest distance piece. If this gap closes up and the actuating arm centralises correctly when the nut of the footrest hanger bolt is slackened, the remedy is to readjust the two locknuts on the footrest distance tube, just behind the plate. Before doing so, slacken the nut of the footrest hanger bolt several turns and also slacken the nut behind the left hand pivot bearing plate which retains the battery bolt anchor. This may seem unnecessary, but it is important. Then unlock the nuts E80 (which measure 1.1 in. (27.94 mm) across the flats) and screw the outer one outwards until it is bearing reasonably hard against the right hand pivot-bearing plate. Tighten up the footrest bolt and check the action of the actuating arm. If correct, lock up the inner nut against the outer and re-tighten the battery bolt anchor nut.
This trouble is unlikely to occur unless the machine has fallen heavily on the offside footrest. If the distance tube nuts are not adjusted quite hard enough against the plate the gearchange may be free when the unit is cold and stiffen up when hot due to thermal expansion. Re-adjust when hot."
The Instruction Sheets 1 - 14 and appendices are available from the Spares Co.
Hope this helps, Frank
