He is happy to be on familiar territory tomorrow.
''It definitely helps to know the course and where you're going, all the climbs and the basics of the tracks that you go past or ride every day,'' he said.
Johnston rode in Armidale, Australia last weekend, finishing sixth in the under-19 category in the World Junior Series race, and 10th in an Australian national series race.
"I'm pleased with that - it was good to see how the Aussies are going before the [Oceania championships].''
That trip and tomorrow's race are part of his preparation for the New Zealand national championship coming up on February 25 and 26 in Wanaka.
Lead-up races in New Zealand have been few and far between.
Summer Cup event manager and Nduro Events owner Tim Farmer said the purpose of the series was, at least in part, to fill the gap left by the absence of a national series.
And, he said, riders had responded since the first series last summer that was run over two rounds, both in Rotorua.
"The competition's gone up and the South Island riders are supporting the series as well. It's probably the only big competition race for cross country mountain biking this summer till the nationals come round.
''We decided this year to make it a non-profit event with the profit going into running the event as cheaply as we can and giving the riders as great a reward as we can.''
Among the other riders to watch out for tomorrow are Dodd, Auckland's Jessica Manchester, also a member of the high performance hub who is fresh off wins in the Junior World Series Race and a junior Australian series race last weekend, and Samantha Kingsford. Late entries have also come in from Nduro Waka 100 winner Jack Compton and road rider and Commonwealth Games bronze medallist Gordon McCauley.