The race involves teams starting at the top of the North Island or bottom of the South Island at the same time to meet in Wellington seven days later.
Around 5am yesterday, Edgar and his three team-mates left from Cape Reinga to ride the 700km to the Parliament buildings.
Edgar has been a keen cyclist since he retired from cricket but the scale of this assignment has him slightly concerned.
"[When] I checked the terrain and how many climbing metres we're doing and the distances we're covering, I gulped. It's a lot of climbing," he laughs.
Edgar maintained a regular training schedule by taking his bike around the country as he went to each of New Zealand's games during summer, including the World Cup matches.
"Even on the day of a game, I would get up and go for a ride."
While he thinks he's a "wee bit underdone" fitness-wise, Edgar is confident he'll have the staying power to go the distance.
Edgar has become a master at discerning what will work and what won't, as his Black Caps selections have shown in recent times. He says the World Cup was like nothing he'd ever experienced.
"Each game was a statement," he says. "Seeing everyone step up at different stages was just fantastic. That game against South Africa at Eden Park - I've never seen such excitement and passion. [The] man hugs and cheering.
"It just brought out what everybody was feeling towards the team, that they'd done something special."
He's quick to downplay his role in the team's run to the World Cup final but there's no denying a degree of satisfaction at the way things turned out.
"I started this selection role in August 2013 and since that time, the World Cup clock at the office was on a countdown.
"I had an involvement in getting the final 15-man squad together and then obviously the combinations on the day. You can look at it and say, 'I had some input into this'."
To support Edgar's fundraising efforts, visit: http://givealittle.co.nz/fundraiser/supportbruceedgar
