RE: Isonic 111 speed
My last and highest top speed on the iS111 / SSR7,6 / orig. 42cm is 64,2km/h (35kn). Wide tail needs correct fin length. Usually fins should be 5-9cm shorter than the "one foot off" dimension. Tail of the 111 is 49,2cm so matching fin sizes in normal slalom dimensions from 40-44cm. Off course you can ride smaller fins for better control and comfort but than you will not be fast and should better bye a freeride board.