Mike "Mouse" McCoy completed the Baja 1000 alone. If you've never seen "Dust To Glory" I suggest you rent it. Awesome movie.
You can argue all you want that it takes more balls, but in the end, they're protected by a cage, whereas a motorcycle racer is protected by nothing.
The biggest balls IMO (or maybe dumbest) are the guys that race the Isle of Man TT. THAT is the definition of manly (or insanity).