Today, Craig Baker (27) and Josh Greer (26) will head to Vancouver to prepare for their adventure - which in 12 months has escalated to a 35,000km trip, across 14 countries beginning in Anchorage, Alaska, and ending at Cape Horn, Argentina, to raise money for South American orphans.
Mr Baker an engineer and welder, originally from Timaru, has been living in Canada for the past year and spending spare time working on the two Kawasaki KLR650 bikes, making some modifications for their seven-month trip.
After arriving in Vancouver, the pair will set up as quickly as possible and then head off by boat to Alaska, "do a U-turn" and start riding south from Anchorage to Cape Horn, Mr Greer said.
"We were sitting around a campfire in Australia on a rock-climbing trip this time last year and dreamed it up.
"We wanted to check out South America and we thought riding motorbikes would be a cool way of going about it.
"Then we decided to go from the top to the bottom.
And then we decided to give a wee bit back to the people that were hanging out down there."
Those people were the South American orphans, of which there were many, Mr Greer said.
"They're young, they have their whole lives ahead of them and they have never had a fair chance at life.
"As adults, we have the chance to make decisions and sometimes they leave us in interesting situations and often there's no-one to blame but ourselves.
These kids, through no fault of their own, have ended up in a disadvantaged situation and it's just not fair, really."
During the self-funded trip, which they had "worked our butts off" to pay for, the pair hoped to raise $10,000.
Mr Greer - who has resigned from his job as an electrician and fire alarm technician - said 100% of donations made through their website would go to chosen charities.
Neither men were strangers to helping others, with experience volunteering in places like Cambodia and India, but it would be the first time they had attempted something of this magnitude.
"We've talked to a lot of people ... we're certainly not going into it completely blind."
They were relying on a sense of humour to get them through the trip, which would see them go from winter in Alaska to 40degC heat in Mexico, and then back to winter.
While they had estimated the journey would take seven months, factoring in visits to orphanages and a bit of rock climbing, Mr Baker said it might take less time.
Meanwhile, Mr Baker's girlfriend, Kelly Blaney (26), of Whangaparaoa, would not be waiting at home.
At the end of this month she will head to Rwanda, to spend six months volunteering in an orphanage.
