A plucky British duo are cycling across Australia on a tandem bicycle in bid to be the first people to circumnavigate the globe on a bike made for two.

Since leaving the United Kingdom in June, university mates George Agate, 23, and John Whybrow, 24, have already cycled 11,000 kilometres across 16 countries.

They described the adventure as a way of avoiding getting real jobs while setting a world record.

But the journey so far has not been without incident.

The men were hit by a bus in Austria, chased by packs of dogs in Romania, caught up in Turkey's failed military coup, and suffered a series of tyre punctures in India while battling to maintain their pace during a fortnight of monsoons.

They even had a setback on their first day of the trip, being forced to sleep in a French bus shelter after their big send-off took longer than they had expected.

"At the end of that day, we thought 'we've bitten something we can't chew'," Mr Agate said.

The duo have encountered many unpaved roads and tracks, including this river path in Serbia. ( Facebook: The Tandem Men )

Prior to the trip neither man had much experience cycling and both worked in hospitality.

"When you start viewing a bicycle as a mode of transport, rather than just something to go for a ride on, it is incredible," Mr Whybrow said.

The duo are now embarking on the toughest leg of the trip — crossing the Nullarbor from Perth to Adelaide over four weeks.

After that their journey will take them through Melbourne and Sydney and then up to Brisbane.

After Australia they will head to New Zealand, before flying to San Francisco and following the Pan-American highway all the way down to Colombia in South America.

They will finish up by flying back to Europe for a final sprint through Spain and France.

The men hope to complete their challenge in under 300 days, thereby setting a new official Guinness world record.

Bike trip follows lengthy planning period

George Agate and John Whybrow left Canterbury Cathedral in June 2016. ( Facebook: The Tandem Men )

The duo were inspired by the 1992 trip of British comedian John Bishop, who cycled from Sydney back to his home in Liverpool.

The 18 months of planning included putting together a day-by-day itinerary, detailing how many miles the men would travel each day, which roads they would take, and how and where they would cross oceans and other impassable sections.

The pair enlisted British explorer Sir Ranulph Fiennes as their patron and are aiming to raise 100,000 pounds along the way for three charities.

Mr Whybrow said it was difficult to find a tandem bike to fit two blokes.

"It's mostly a husband and wife thing to do," he laughed.

"Our mates thought we were mad," Mr Agate said.

"There was a sweepstake going at my work for when we were going to give up. A lot of people had it down for the ferry to France."

The men contacted more than 500 companies for sponsorship and managed to raise about $50,000 between 11 sponsors.

The duo are travelling light with only one set of clothes to wear off the bike, two sets of lycra each, and some camping equipment.

Bike pair overwhelmed by attention

Tandem Men George Agate and John Whybrow inspect a punctured tyre near Australind in WA's south-west. ( ABC News: Robert Keunig-Luck )

The Tandem Men have garnered a considerable amount of publicity during their trip, some less welcome than others.

"The amount of attention and curiosity we received in India was just incredible, we had drivers taking selfies and then swerving into us," Mr Agate said.

"People would just drive in front of you, slam the brakes on, get out the car and take picture and then do it all again."

George Agate dangles a carrot in front of John Whybrow during training for the tandem bike adventure. ( Facebook: The Tandem Men )

Mr Agate said there had been a few times when the pair had considered giving up.

"There was one time in Austria, the rain was coming down so hard, we had to pull off the road into a closed supermarket in the evening," he said.

"We took shelter in the trolley bay and rain just kept coming down so we couldn't carry on, so ended up sleeping under the trolley one night."

"We hardly got any sleep and were flinching at anything that came into the car park."

Tandem Men George Agate and John Whybrow pictured in Perth shortly before they set off for the Australian leg of the trip ( ABC News: Robert Koenig-Luck )

But the week still managed to take a turn for the worse, Mr Whybrow said.

"We got hit by a bus, that wasn't a good week," he said.

Mr Whybrow said the trip had taught them that nothing was impossible.

The pair are keeping a diary and hope to write a book about the experience.

When asked if there was anything they would do differently as part of the experience, both men were quick with a response.

"I probably wouldn't have gone with him," Mr Agate bantered.

"The feeling is mutual," Mr Whybrow replied.