Tauranga teenager Roydon White (KTM) moves to MX2 after a top-10 finish last season in the 125cc youth class.
The defending MX2 champ is Hamilton veteran Darryll King (Yamaha), while in-form riders in early season events have been Masterton's Luke Burkhart (KTM) and Queenstown international Scott Columb (Suzuki).
It's in the combined 125cc and Youth MX (under-21) category where the rising stars of BOP motocross have a chance to shine.
Tauranga's Scott Barr-Smith was an impressive runner-up to Ethan Martens last year and has switched from KTM to Honda, while Te Puke's Logan Blackburn (Yamaha) had the best possible buildup to the nationals by winning the 125cc Grand Prix title at Woodville last month.
Blackburn finished 10th in the 125cc title last year at his first attempt. Yamaha riders Garth Amrein (Katikati) and Cameron Vaughan (Rotorua), who were 125cc podium finishers at the Woodville GP, make their first attempt at the nationals since stepping up from the junior ranks.
The motocross nationals are decided over four rounds.
After the Timaru opener on Sunday, the second round is at Patetonga in Thames Valley on February 26.
Round three is at Pukekohe on March 4 and the final is at Taupo on March 18.
Obstacle dodgers
The local two-wheel action this weekend is the third annual Endurocross at the Te Puke A&P; Show. Organised by Te Puke Motorcycle Club, the endurocross is a spectator-friendly hybrid of enduro riding, supercross and arena trials with the showgrounds course formed from logs, rocks, sawdust, chopped firewood, earthmover tyres, car bodies and flat-bed truck trailers.
A series of heats, semifinals and a final with dead-engine starts assures plenty of handlebar-to-handlebar action while the main innovation for this year is a separate trials bike class.
Among the top riders will be Tauranga's Reece Burgess, a leading enduro racer and podium finisher at last year's Tarawera 100 off-road endurance race.
Burgess says the Endurocross is an exciting challenge and a great spectator event.
"A lot of people look at the obstacles and think they can't ride them," says Burgess, who campaigns a big Husaberg 450cc enduro machine.
"But the course is rideable and the important thing is trying to maintain some momentum.
"With hot weather and without the speed that you have when you ride in the bush it uses a lot of energy in a short time.
"The things that saps your strength is when you stop and really have to muscle the bike, especially for me because I'm 75kg and my bike is 114kg."
Practice sessions will start about 9.30am with the finals expected to run mid-afternoon.
Records broken
Te Puke teenager Michael Scott continued his string of podium finishes in the New Zealand Formula Ford Championship during the penultimate round raced at Hampton Downs last weekend.
Scott, who recently turned 17, went into the NZ Motor Cup meeting at Hampton Downs holding a clear second place in the championship behind defending champion Andre Heimgartner (Auckland).
After qualifying third fastest in his Mygale, Scott gained a second placing and two thirds in the three races to place second overall in the round and maintain second place in the standings.
The Hampton Downs Formula Ford lap record was broken in all three races and when Heimgartner set the new benchmark of 1m 09.493s in the final race of the weekend Scott was just 0.185secs slower.
The final of the Formula Ford Championship is at Manfeild this weekend supporting the New Zealand Grand Prix, which is the final round of the Toyota Racing Series.
Scott also races in the Formula First category and the Hampton Downs meeting was the one occasion this summer which required him to complete double duty.
He recorded a second, third and fourth placing in the Formula First races as well as the fastest lap of the weekend, adapting well between the two very different kinds of single-seater.
In the Formula First championship Scott remains fifth with two rounds remaining at Manfeild (Feb 25-26) and Taupo at Easter weekend.
Tight finish
The annual Motorsport BOP dual sprint event at the Taupo motor race circuit on Sunday saw 46 drivers in action.
Rotorua Car Club competitor Eddie Pinkham set the fastest lap time in his four wheel-drive Nissan Skyline while Tauranga GTNZ competitor Richard Grainger (Mitsubishi Lancer Evo) finished second.
Grainger was an early pace-setter but was sidelined by a broken brake disc and only completed one official run.
Tauranga's Derek Cecil (BMW M3) and Nathan Lord (Mazda RX7) and Waikato driver Troy Bell (BMW E36) were separated by just 0.29secs to complete the top-five positions.
Motorsport BOP Taupo track dual sprint:
1 Eddie Pinkham (Nissan Skyline) 1m 13.29s; 2 Richard Grainger (Mitsubishi Lancer Evo) 1m 15.25s; 3 Derek Cecil (BMW M3) 1m 19.22s; 4 Nathan Lord (Mazda RX7) 1m 19.45s; 5 Troy Bell (BMW E36) 1m 19.51s; 6 Gary Skinner (Subaru Impreza WRX) 1m 20.10s; 7 Shane Ward (Honda CRX) 1m 20.50s; 8 Dave Stephens (BMW M3) 1m 20.84s; 9 Michael Clark (Holden Commodore) 1m 20.91s; 10 James De La Haye (Subaru Impreza WRX) 1m 20.92s.Who'll eat dirt?The Waihi Beach Dirt Track is a busy venue this weekend with the annual challenge event against the Waiuku Dirt Track Club and regular club racing on Saturday.
On Sunday competitors from Motorsport BOP will be all action at the track with a "cat-and-mouse" autocross event which gets underway at noon.
The other Sunday event on the local motorsport menu is the opening round of the BOP Kart Club points series at Fagans Valley Raceway near Te Puke.