The group's founding member Richey Edwards went missing in 1994 and though the band have continued their career - joined on stage by additional musicians - the bassist insists they could never permanently replace The Rhythm guitarist.
Nicky said: "You can't replace the irreplaceable. It's been hard enough to carry on as a three piece, but we've found a different way of doing it. It doesn't mean we're a better or worse band for it."
Nicky is planning to release a book of Polaroid photos by the band later this year and will then start work on an autobiography, though he is unsure when it will be finished as it is such a huge project to undertake.
He explained to website Toazted.com: "The second book is a big one, an autobiography really, a history of myself and the band. It's a big thing to do. Having said I was gonna do it, it's gonna be a lot of effort and that'll take a few years. At the moment I'm committing myself to things and I haven't got time to do them. But it'll get done eventually.
"I've got chapters and titles, I just need a rhythm to it, I don't want to bore people with my childhood because that was lovely, mam and dad were great, I did well in school. I think people would rather know about me and the band than just me.
"I think I'll try and do it on my own but that's not to say I'll finish it on my own. There's plenty of writers I know, but I'll give it a go."