I am by no means a tire expert nor mechanic so I googled "bias ply v. radial motorcycle tires." Found this on the Dulop web site in the q & a section:
Can I change my tires from bias ply to radial or vice versa?
Bias and radial tires have significantly different dynamic properties. They deflect differently, create different cornering forces, have different damping characteristics, as well as other differences. In order for radial tires to be introduced into the two-wheel market, it was necessary to change certain characteristics of the motorcycle. The introduction of the radial tire led to such things as modified frames, new steering geometries and suspensions. Therefore, it is recommended that a motorcycle be used with the type of tire construction that it came with originally. If a change is to be made, then it should only be done if the motorcycle or tire manufacturer has approved the change. Above all, do not mix bias ply and radial tires on the same motorcycle unless it is with the approval of the motorcycle or tire manufacturer.