I took a chance and went with Ikon 7614 aluminium with screw thread preload and 4 position rebound damping and it paid off. Up front the stock springs were exchanged for Progresive springs. After about 250 miles now of both cruising and twisty back roads I am absolutely satisfied.
This configuration was worked out with Brent by ordering from the newthruxton.com page with a request for a length of 13.5" to fit the stock Speedmaster hieght. Lowering was considered but since I still greatly enjoy twisty backroads roads I did not wish to take a chance on to much scrapping.
