As a method of transport, it has never seemed the most practical.

But for John Whybrow and George Agate, a tandem bicycle will have to get them around the world and back.

The two friends are preparing to embark on a round-the-world trip which will take them 10 months, covering 18,000 miles across six continents and 30 countries.

They hope that the journey will secure them an entry in the Guinness World Record, as the first to circumnavigate the globe on a tandem.

The friends are riding unassisted and will sleep most nights in a tent, carrying all their equipment with them.

Both men are over 6ft tall and have had to had a bicycle custom made to fit them both. It has been specially designed to separate in two, to be more easily stowed on aeroplanes.

Until the machine is ready the pair have been training on a 1980s Peugeot tandem - lovingly named Pedro. They leave on June 8.

Mr Whybrow, who grew up in Hunstanton and attended Smithdon High School, said: 'I think the excitement outweighs the nervousness, the most nervous people are probably our parents.'

The idea was conceived two years ago while the pair were studying at the University of Kent in Canterbury. The historic gates of the Cathedral will bookend the start and finish of their route.

The 24-year-old politics graduate, who now works as a restaurant manager in Canterbury, said: 'It was one of those things which started off as a mad idea.

'We knew we wanted to go travelling together and we planned to go on a cycle trip across Europe for two months or so.

'As soon as we started planning it, it got out of control.'

Mr Whybrow and 22-year-old Mr Agate, who works in Canterbury as a bar manager and is from Pulborough in West Sussex, were inspired by their patron Sir Ranulph Fiennes' pole to pole circumnavigation, as well as Mark Beaumont's record-breaking circumnavigation of 2008.

'The ride is going to be riddled with challenges, both physically and mentally, but overcoming these will be a great achievement,' said Mr Agate.

Some challenges have been met, even before the ride has begun. One major one was finding a bicycle that would fit them.

'Finding one for two men over 6ft was difficult, we had to go for 100pc bespoke,' said Mr Whybrow, who will take the front seat.

'It's not the sort of trip you can train for that easily, it's a real slow burner. Every spare sunlight hour is spent out on a bike, which isn't easy when we're working 40 to 50 hour weeks.

'Planning time around that is pretty difficult. Most work in the last year has been the planning side of it,' added Mr Whybrow.

The pair are aiming to raise £100,000, which will be split between Kent homeless charity? Porchlight, Great Ormond Street Hospital and Water Aid.

You can sponsor the men at virginmoneygiving.com/team/thetandemmen.

Keep up with the men follow their progress around the world via www.thetandemmen.com