Riders such as Tokoroa's Jake Wightman, Paeroa's Chris Power, Taumarunui's Cody Davey, Whanganui's Seth Reardon, Cambridge's Beau Taylor and Stratford's Josh Hunger may also fancy their chances of pinching overall victory in the AA Grade for the day on Saturday and/or Sunday, but, in reality, hopes of winning the title this year may be beyond their reach.
But there will still be plenty to fight for in the battle-within-the-battle for the various separate class honours, each one of them also on the line this weekend.
For example, Groombridge currently leads the combined under-200cc two-stroke class and under-300cc four-stroke class from Davey and Reardon; Whitaker leads the over-200cc two-stroke class from Wightman; Power leads the over-300cc four-stroke class from Hunger and Rotorua's Spence McClintock leads the veterans' (over 40 years') class from Hamilton's Phil Singleton.
The same scenario applies in the A Grade, where Cairns leads the women's class from Auckland's Julia Williams and Taupo's Deidre Kiernan; Masterton's Sam Callaghan leads the under-300cc and under-200cc two-stroke class from Tokoroa's Nick Wightman; Skinner leads the Veterans 2 (50-54 years') class from Helensville's John Buxton; Auckland's Jeff Van Hout leads the Veterans 3 (over-55 years') class and Masterton's George Callaghan leads the Veterans 4 (40-49 years') class.