It's probably not much worse than riding drunk, degree for degree, which is to say it's not advisable. But I think the coppers are moving to equip all booze buses with drug test units as well. Either way, you'll probably have a better time if you leave the bike at home and write yourself off good and proper without having to take it easy for the sake of riding. Oh, and don't Bogart. Nobody likes a man who Bogarts.