 Their first entry in the Isle of Man TT, in 1912, led to a ninth place and mainly modest results came during the following years with OK-Supreme machines scoring three podium places and 34 finishes.After the war OK produced a 292 cc two-stroke motor of its own, but also produced models using Blackburne (250 cc and 350 cc, sv and ohv), Bradshaw (348 cc oil cooled), and JAP (246 cc to 496 cc) engines.In the 1922 TT OK-Supreme machines placed sixth and seventh, with the fastest lap being set by Wal Handley at , but he failed to finish the race.