The rugby-mad duo cycling from Twickenham to Tokyo

Hanoi - They survived angry dogs in Iran and stomach bugs in India, and have slept in monasteries, underpasses and on farms - it's been a madcap adventure for a pair of rugby enthusiasts cycling from Twickenham to Tokyo for charity ahead of the Rugby World Cup.

With little more than a weathered map in their baggage, Ron Rutland and James Owens have been on the road for 191 days and counting, having set off from London in February.

The clock is ticking, however, as Rutland and Owens are also carrying the whistle which will be used for the Rugby World Cup's September 20 curtain-raiser between Japan and Russia in Tokyo.

The trip's aim: to raise cash for the tournament's official charity, ChildFund Pass It Back, and to spread the gospel of rugby in parts of the world where few people have ever heard of the game, as Japan prepares to host Asia's first Rugby World Cup.

But the bushy-bearded pair, who barely knew each other before embarking on the 20 000km, 231-day journey, said they have found so much more along the way.

"Cycling through countries like Iran and Turkey, numerous times people slowed down, opened their windows, handed us Cokes and water, oranges and fruit, countless, countless times," said South African-born Rutland, a former rugby player.

"Little acts of kindness like that... really make you see the best of the human spirit," he added, speaking to AFP on the Vietnam leg of the trip.

It wasn't just free food that humbled the burly 45-year-old.

A monk in Myanmar opened his monastery to them, they stayed with families in Tajikistan, and when the weather was warm enough they pitched their tent wherever they could.

It's not the first jaw-dropping expedition for Rutland, who used to work in a bank.

He cycled through every country in Africa en route to the 2015 Rugby World Cup in England, and in 2017 played what has been billed as the longest hole of golf in history - 80 days and 20 000 shots in total - across Mongolia.

But this trip came with a few special challenges.

Following hip replacement surgery in 2018, Rutland says he set out from London "not quite the fattest of my life but not far off".

He's also vegan, and finding animal-free grub in meat-mad central Asia was no easy task, especially when averaging about 600km a week on the bike.

"You end up eating a lot of rubbish, just to get enough calories," he said.

His cycling partner Owens, a Hong Kong-born Brit whose father happens to be Rutland's doctor, has a less restrictive diet.

But still, both came down with stomach bugs in India.

"You just have to get better on the bike," said Owens, who worked for ChildFund Pass It Back in Laos and Vietnam before embarking on the 27-country overland trip.

They say they've been lucky so far; besides a few minor spills and a few bike repairs - their handlebars came loose after corroding from sweat - the worst they've encountered are some aggressive street dogs in Iran and Turkey.

So far they've only had one day off and will cycle the full route save for a few ferry rides - one across the English Channel, another on the Bosphorus strait in Turkey and finally from Shanghai to Osaka for the final leg.

They've learned to pack light along the way.

Besides a few first-aid essentials, very little clothing and a GPS tracker mapping their real-time progress online, they only have two crucial pieces of cargo: that world map, and the all-important gold whistle.

Oh, and a rugby ball that they bring out wherever they go - in a bid to teach rugby to locals in places like Bulgaria, India, Vietnam and Laos, where rugby remains for the most part an unknown sport.

"That's been a really good ice-breaker, especially with children," said Owens, 28, whose work with ChildFund has helped bring rugby training and lifeskills programs to remote corners of Southeast Asia.

They've also learned a lot about each other. One is a self-described "obsessive" planner (Rutland), the other less so. One is a morning person (Rutland again), the other not so much.

But that planning has served them well. They've stayed mostly on schedule cycling though the European winter, along to Central and Southeast Asia, and on Sunday are heading north to China from Vietnam.

They will eventually wheel their way over to Japan to watch the tournament, and despite a few frictions over who they want to see crowned - Rutland is rooting for South Africa, Owens for England - they both agree they'd like to see Japan go far.

"It's a once-in-a-generation opportunity for the game in Asia," says Rutland.