Nick is the kind of dude that, when he tries to move around a bike like the Ducatis... he just falls over to the side over the motorcycle because he doesn't have the body strength to do it, and probably ends up making up excuses when somebody ask him about all the screeching on the side of the bike and the missing rearview mirror... that's Nick.
And alcoholism causes a lot of muscle strength loss, problems calculate distance, speed, reaction times, and everything that you need to be on your best when you are on a bike.
Terrible idea from Nick... but it is Nick so... not surprised, at all.