If the Duc is still dry clutch your options are much greater. JASO MA rating is ideal for wet clutch applications which may not be the case for you (it isn't for the Duc in our garage). Motorcycle transmissions are still hard on oil as the shear rates may be higher than automotive applications. We have been very happy with amsoil, bike shops may actually be cheaper than canadian tire, the local shop has 20/50 for $55 for a one gallon jug. Motul full synth is good (smells nice too), and Bel-Ray full synth and semi is also good stuff.