Ryuichi Kiyonari admits he is feeling pressure to defend his British Superbike Championship crown in 2011, ahead of this year's curtain raiser at Brands Hatch.

Unlike most of his anticipated rivals, Kiyonari has not switched teams over the winter, staying with HM Plant Honda as he bids for a fourth BSB title in four consecutive attempts.

With much of the pre-season testing occurring in an unofficial capacity, Kiyonari confesses he doesn't know exactly where the competition is likely to come from, a pressure he will feel heading into the opening weekend.

"Our pre-season testing has been very good. At every circuit we had lots to test, probably more than last year, but with Shakey we have worked together and we have been getting faster. We have tried very hard over the winter to improve as we want to win again! It is going to be important to be winning races at every round.

"There is a lot of pressure before Brands Hatch for everyone because nobody knows who is going to be fast. There is pressure on me because I am champion, but after the first race I think we can relax a little because there is so much that is unknown before we start racing."

Even so, Kiyonari is certain new team-mate Shane Byrne - champion for Airwaves Ducati in 2008 - will be a reckoned force from the off.

"Shakey is especially fast at Brands Hatch and we are quite equal with our settings and our Fireblades so we will have to wait to see who is faster!

"I think the riders that were fighting for the championship last season will be there again and there are so many other riders who will also be fast. I want to win at Brands Hatch, for myself and the team and also the people of Japan."