Two-time World Superbike champion Jonathan Rea says he is "more proud" of taking the 2016 crown compared to his first title last year, which felt "almost easy".
Longtime Honda rider Rea joined Kawasaki in 2015 and, after he became the dominant champion of the series, the team switched to a new base model of ZX-10R bike for 2016.
While his 2015 title was achieved with a bike that had been developed for several years, Rea said winning this year's title with new machinery was even more satisfying.
"My 2015 championship felt like [it was] not true, we were winning for fun, it was almost easy," said Rea, who became the fourth WSBK rider to defend his title, and the first since Carl Fogarty in 1999.
"The bike was so competitive after many years of development. This season I felt like I really had to win the championship.
"We got the bike early in the winter test and we had a lot of work to do on the bike, so I'm really happy, probably more proud to win this championship in the first year of a new model."
Rea kicked off the season with three wins and, having stood on the podium in each of the first 17 races, he established a safe lead over teammate Tom Sykes and Ducati rider Chaz Davies.
Although two consecutive retirements followed, and he couldn't win for the rest of the season thanks to Davies' dominant run, he eventually secured the title with one race to spare in Qatar.
"We had more difficulties and challenges than in 2015," added Rea. "The new challenge with the new bike, it makes this title almost sweeter.
"What happened last season was incredible: we almost reached the points record; we won the championship at a ridiculously early point of the season. But the end of this season was dominated by Chaz and Ducati.
"In the winter test I felt like a world champion, but the underdog for this season.
"My team gave me an incredible bike, and in the first races at Phillip Island, we got back to putting a championship together, which is what we do quite well here in KRT - not just with me in the past two seasons, but with Tom Sykes in 2013.
"I think as a rider I learnt to understand when it's possible to win and when it's not possible you have to understand where you can finish."