Bike Bandit (a CA-based internet motorcycle accessory store) has published an mildly interesting article comparing radial motorcycle tires with bias-ply tires. One of the things that I personally found fascinating is that they say never to use radial tires on spoked wheel rims using inner tubes. I found that kind of funny as my 1997 BMW Funduro came from the factory with spoked wheel rims, inner tubes, a bias-ply tire on the front wheel and a radial tire on the rear wheel. But then, BMW does tend to do things their way.
http://www.bikebandit.com/blog/post/bias-ply-vs-radial-which-one-is-best-for-you
