The men's downhill competition is shaping up to be a real humdinger between New Zealand-based professionals Brook MacDonald and George Brannigan, Cam Cole and Sam Blenkinsop all vying for the rights to wear the national jersey in Europe this year.
McDonald was the leading Kiwi in 2012, finishing the year ranked sixth in the world.
Brannigan was ninth in his first full season at top level, with Cole 15th and Blenkinsop 20th.
All four riders race professionally overseas but have made the effort to be in New Zealand for this annual event, which doubles as the feature show of the Rotorua Bike Festival.
Cooper headlines the men's cross-country event alongside Dirk Peters (Rotorua) in what should largely be a two-horse race.
The pair are both still under-23 but, with the class being run with the elite riders, they are favoured to also fight out for the overall honours. They were separated by a few seconds in their last outing.
Cooper, 18, has recently signed with Cannondale Factory Racing and is widely regarded as an emerging talent in world mountain biking. Peters, 21, is a two-time age-group national champion and has enjoyed a great start to 2013 with wins in the Bluff and Wellington rounds of the BikeNZ MTB Cup series.
The women's cross country race looks to be another Kiwi dual between London 2012 Olympian Karen Hanlen (Whakatane) and 22-year-old Samara Sheppard (Wellington).
Hanlen, 32, is in great form as she blitzed the field in the final round of the MTB Cup series in Hunua on the weekend to win by almost five minutes. Sheppard has recently signed with Belgium-based UCI trade team Toka Print Mountain Bike so would love to head to Europe with the New Zealand title.
Despite not being eligible for the title, this event has attracted a number of quality international riders, including entries from France, UK, Japan, Canada, Germany and Australia.