The fork size is measure at the slider. Marcs are 40 mm, monster and SS Showas ( non adjustable & adjustable) are 41mm, SBK Showas and Ohlins R&T are 43mm. The new Hypermotard is 50mm.
And don't the HM forks look amazing! Won't be long before someone gets a pair, has some clamps made up and switches over their radial calipers on their S4R* and giggles like a girl!