I've read almost all of Arthur C. Clarke's novels. The Rama sequels are nothing like his work. It's easy to believe that he barely contributed.

I always felt that Gentry Lee kidnapped Clarke and forced him to be his co-author.

Clarke was so much of a better writer than the [2010|Rama] sequels indicate. He would not be able to screw it up so thoroughly without extensive "help".

Clarke also made some good partnerships - Richter 10 is a very good book. Sadly, the partner died and never worked with Clarke again. Gentry Lee would be my main suspect.

The terrible bits were all stuff that Clarke never wrote in any of his solo novels.