Jack on Friday morning sent a photograph of the bike safely back with him in the main street of Banff after it went missing when he boarded a Qantas flight from Sydney to San Francisco on Monday.

Finding it, getting it back and then reassembling it in time has been almost as big a challenge as the race.

"I am so exhausted," he said, with a laugh.

The 27-year-old adventurer had been training in Canberra for eight months for the challenge in which hundreds of cyclists will ride from Banff in Canada to Antelope Wells in New Mexico on the US-Mexico border, a distance of 4481km.

It's as much a survival challenge as anything else, with everything Jack needed for it packed with the bike.

When Jack arrived in San Francisco en-route to Canada, the custom-built Hunt Bikes Land Cruiser and the accompanying gear was nowhere to be seen and Qantas said it had no record of it, despite him checking it in at Sydney International Airport for the direct flight.

After some frantic posting and phone calls, the power of social media and a diligent worker at Sydney airport eventually saved the day.

Jack said a supervisor at Star Aviation Services in Sydney saw a Facebook post about the missing bike and went looking for it - and found it.

The bike was put on an Air Canada flight to Vancouver and then delivered to Banff about 4.30am on Thursday (Canada time).

Jack said he was upset that Qantas had not found the bike, someone else had.

"It's literally taken a random worker at Sydney airport and Air Canada to get it to me, " he said.

Qantas did not respond on the record, only confirming the bike had been found and was being reunited with Jack.

The ultra-cycling challenge crisscrosses the Continental Divide from north to south, riders taking advantage of the long summer days to get in as much cycling as possible before nightfall. It starts at 8am Friday Canada time, midnight Friday Canberra time.

Jack, a former St Edmund's College student, will be cheered on by mum Leonie in Canberra who was trying to do all she could to locate the bike.

"We're all extremely relieved. It's so difficult when you are so far away and can't really support him as much as you'd like to," she said.

The family was also very grateful for the support and good wishes of the Canberra community.

"And to the young man working at Sydney airport who ensured the bike got there safely and kept us informed of its progress," she said.