Smith had been linked with a move up to the new Moto2 series
Oxfordshire's Bradley Smith says mental toughness will determine who will win this year's 125cc world championship.
Smith, 19, will take to the track for the first race of the season in Qatar on 11 April.
"The ability of the riders and the packages underneath them are so close, it comes down to that mental edge," Smith told BBC Oxford.
"And mentally, I am ready. Race craft wise I have learned a lot from last year," he added.
Smith won two races and notched nine podium finishes on his way to second place in last year's world championship, finishing runner-up to Spain's Julian Simon.
"I was definitely forced to get stronger in my mind racing against Simon last year and the package underneath me is the best there is out there," Smith continued.
"I've just been waiting for it all to start but there are always six riders who line up on the grid with a chance of winning or getting a podium," he added.
Smith, who will ride alongside Nico Terol for the Bancaja Aprilia team, is one of the favourites to win the 125cc title but admits he would have considered moving up into the new Moto2 class.
I have been playing a bit of a guessing game with the other guys and when the racing starts I will be there
He said: "I already have four seasons in the same class in 125's, and it definitely would have been nice to have the opportunity on the new bike.
"Obviously Moto2 is a new project and it's down to the team and the rider to find a good setting this year, I quite like the idea of that.
"I am disappointed I didn't get the chance to move up, but when I think of becoming world champion in 125s that really does spur me on."
Smith has one final round of testing with his team in Spain but says he has been cautious not to show his hand too early to his competitors in pre-season.
"I've learned over the last few years that you don't get much time during the season to test things.
"Although it is hard mentally to see yourself down on the timesheets it is really important to test the new equipment and find improvements.
"It hasn't been nice to see myself down in fifth and sixth places, but I have been playing a bit of a guessing game with the other guys and when the racing starts I will be there."