Seating

A sprung saddle was used on all rigid models and on plunger frames up to 1952, which was then replaced by a dual seat. Black painted parallel-sided support springs were used up to 1950, there after chrome plated, barrel shaped springs were used which will fit earlier. The dual seat used on the 1954 swinging arm machines had a flat base towards the front and was held on by studs screwed into tapped bosses in the base. The 1955-58 seat pan is higher at the front and uses ‘Spire’ bolts and nuts to retain it, although these are often replaced by welded on bolts, studs or nuts as they are prone to damage. The 2 versions of swinging arm dual seat only vary slightly in appearance once covered. Beige dual seats are usually fitted to bikes with maroon paintwork and black seats to black painted machines. Sprung saddles will not satisfactorily fit 1954 and later Square Fours.