Direct replacement pair of progressive fork springs for shuttle valve type forks fitted to BSA A50 and A65 1969 to 1970 , also fits Rocket 3 and T150 with shuttle valve forks.
The progressive spring reduces brake dive and helps prevent bottoming out of the forks under extreme braking or sudden bumps. The spring is rated for solo use , not for sidecar use.
NB, Please note that BSA/Triumph used different spring lower cups , check this spring will fit, it has dimension of 51.5mm OD and ID 39.5mm, if you have springs size of 49.0mm OD x 39.5mm, then see Triumph part number SRM-97.1891-PRO
For fitment-tight coils towards lower spring cup.