Some fans, media and motorcycle racing observers were surprised when MotoGP veteran Shane "Shakey" Byrne rejected an offer to ride Paul Bird Motorsport's Claiming Rules Team bike this season in the World Championship, instead staying with PBM's team in British Superbike.

But reigning BSB champion Byrne said his decision to aim for an unprecedented fourth BSB title on PBM's Kawasaki was easy.

"Why would I leave?" Byrne said to the BBC. "All I've done is equal a record with two other riders. I aim to break records, not equal them."

"What do I need to prove at that level? It really, really annoys me when people question why I've stayed and say I'm not getting any younger. I'm two race wins from being the most successful-ever race winner in BSB, I'm fighting for an unprecedented fourth title, and I'm hungrier than ever."

Byrne, 36, is tied with the retired Niall Mackenzie and Ryuichi Kiyonari, who is riding in the series this season with Samsung Honda, with three BSB championships apiece.

Perhaps memories of his MotoGP stint in 2004-05 are enough to keep Byrne away from racing production-based equipment in the World Championship. He missed several races due to injury in 2004 on a diabolical Aprilia, and he rode a partial season in 2005 for Kenny Roberts' team and Camel Honda, finishing 24th in the season standings.

"But I soon realized the guys you're riding against in MotoGP are just as talented, but the machinery differences mean if you're not on the right bike, you get nowhere," Byrne said. "And, to be honest, that was a real bitter pill to swallow. We've seen what can happen, with Rossi struggling these last two years.