@Urban , The Ringworld Engineers was indeed authored by Niven, but it was written in response to fans who’d ripped the first book because of its inattention to the realities of orbital mechanics. As sequels go, it’s pretty disappointing. It isn’t a bad novel, but the first one was so good it should have stood alone. Niven should have just stood up at the Con and told those idiots the whole idea behind Science Fiction is to suspend disbelief. I can’t understand why an author of his stature would cave into that kind of pressure, and considering how stinking rich the guy is, I don’t know why he would even care.
If you read The Integral Trees and its sequel The Smoke Ring, you’ll get a better idea of how well Niven can write sequels. Likewise, The Mote in God’s Eye and The Gripping Hand, which he wrote with occasional collaborator Jerry Pournelle.
Niven is hardly an obscure author, though. @phoenix13, same goes for Frederick Pohl, but if you haven’t read them, start now. Pohl’s Gateway series is particularly engaging.