I'm just sitting here writing a post for later about hobbies and literally just wrote this line...
I'm not sure what exactly defines a hobby however I figure it's simply an activity a person does in one's spare time and for enjoyment. Basically something other than one's job, profession or vocation although I think getting some financial recompense for one's hobby isn't against the rules. Look at us all here hobbying on hive for example.
It sounds like your mate is writing for his hobby, and work. :)
I think he's a writer. It's all he's ever been. His dad started the business and he's quite successful at it. Got his degree at Cambridge and has been writing ever since.
He's a RIDER too. He just happens to share some of his rides and 'things' with the world. I think that's how he has it in his head.
Sounds like an all-round sort of guy.