The former Olympic speed skater - a man with remarkable thigh muscles who once had a resting heart rate of 34bpm - leaves on his quest on August 12.
To break the standing record of 125 days, 21 hours and 45 minutes, he will have to cycle close to 240km a day, alone, with no back-up.
Mr Nicholson is taking on the challenge to raise money and awareness for the University of Otago's Te Aho Matatu: Centre for Translational Cancer Research.
The plan came after he late last year broke the New Zealand outdoor 24-hour cycling record at the Mosgiel velodrome, raising money for the same organisation.
On that occasion the 44-year-old cycled 776.77km.
Mr Nicholson said he would be making the trip mostly alone.
Accommodation would be provided by friends, skating contacts and extended family.
The trip would start in Auckland, from where he will fly to Vancouver, cross Canada and the United States, through Europe to India and through Southeast Asia, across Australia, then the length of New Zealand back to Auckland.
The total distance required is 28,970km.
Mr Nicholson said the rules of the Guinness record allowed him to skirt war-torn countries.
''Within the rules, I've tried to maximise my time in countries where the conditions will be less challenging, and minimise my time in those where they will be difficult.''
The relief teacher, and Moana Pool fitness instructor said he had to dip into his own pocket for air fares.
Part of his motivation to raise money for the Centre for Translational Cancer Research was the recent death of a friend from cancer.
The sheer physical effort of completing the ride was not something new for a man who had a long background as an athlete, including competing in three Winter Olympic Games as a speed skater.
''The bottom line is if you want to excel in physically demanding sport you need to put your body through challenges.
''I've become quite used to that.
''You just become very hardened to discomforts that you experience.
On whether he was confident he could beat the record, Mr Nicholson said he was ''quite confident I can easily chip out the miles''.
''I think where I'm going to have to make sure I succeed is looking after the body."
Donations can be made to givealittle.co.nz/cause/teahoworldride/
