THERE are a few things you could set your sights on doing in your midseventies, but riding a pizza delivery bike the length of South America wouldn’t naturally be high on the list.

Then Simon Gandolfi has always been likely to grow old disgracefully. A conversation with him is punctuated by stories of playing blackjack in low dives in hot countries, shooting crocodiles for a living, skippering yachts, riding with the mujahadeen in Afghanistan or charming dodgy border guards in even dodgier countries.

He lived in Ibiza throughout the Sixties and Castro’s Cuba for five years in the Nineties, which for a middle class, white Englishman with a public school accent honed on the playing fields of Ampleforth, was no mean feat.

His full surname is actually Gandolfi-Hornyold and a few centuries ago would have connected him to European royalty or Spanish Conquistadors at the very least. But he is as native as the Malvern Water that gushes out of the hills not far from where he lives.

A knock on his cottage door in Colwall was followed by a brown blur hurtling past like an Exocet and out into the garden. There followed a lively few minutes, both verbally and physically, while Simon, who still bears the aftermath of a broken leg and is now 75, retrieved a disobedient terrier from the herbaceous border and then led us into the sitting room.

Throwing another log on the fire, he draped his damaged leg over the arm of a chair and settled down to talk about his latest book. Old Man on a Bike is the story of a 28,000-mile journey from Veracruz in Mexico to Ushuaia in Tierra del Fuegio on a 125 Honda.

“You’re going where?” the man at Moto Diaz, the main Honda agent in Veracruz had asked him when he picked up the machine. “On a pizza delivery bike?”

Nevertheless the grey-haired mechanic who gave it the once over, assured him it would make the journey: “Sin problemas.” Although the mechanic, of course, wasn’t going.

The decision to embark on this escapade was hardly caused by midlife crises. “But age did have much to do with it,” Simon said. “My wife is younger by almost 30 years. I feel old and I suspect our teenage sons find me an embarrassment. Their friends mistake me for their grandad – or an old tramp.”

So, at the age of 73, he felt an adventure was in order to prove there was still life in the old dog.

But there was another reason.

“Although I have lived abroad much of my life, I am very English, probably something of a Blimp. I believed that honour was intrinsic to being English. In public service we behaved better. Then came the Iraq war and the disclosure of Abu Ghraib.”

In case it’s slipped your memory, Abu Ghraib was the prison in Baghdad where military police attached to the American army carried out abuse and torture of Iraqi inmates.

The subsequent details and pictures caused a political storm and did nothing to further relations between the West and the Muslim world. They also drilled a thought deep into Simon Gandolfi’s brain. How does the rest of the world see the British?

Do they differentiate between Britain and the USA? Do they think England is a country populated by football hooligans? And is South and Central America full of drug dealers and corrupt cops?

His motorbike journey was also a way of finding out how others now see us and how we see them. The idea, he maintains, was his wife’s.

“ ‘Ride a motorbike,’ she said. ‘It’s something you’ve talked about as long as I’ve known you.’ I replied, I’m too old. ‘So get young again.’ ”

It also kept him out of her hair for six months.

On the merit side, this was a part of the world he knew quite well, for Simon Gandolfi has previous in South America. He is also a successful author with 10 novels under his belt.

The major parts of two of them were written in Santo Domingo, capital of the Dominican Republic and, as earlier, he has lived in Cuba.

However, Old Man on a Bike is his first work of non-fiction. Although parts are so hilarious as to easily come in the category You Couldn’t Make It Up. His brushes with Latin American police forces and border controls easily qualify here.

Stumped by an unfailingly polite, aged Englishman with eccentric ideas and sometimes the wrong documents, their response to the impending mountains of form filling, was to welcome him in the front door of the police station and send him out the back and on his way with no more questions asked.

On the technical side, the Honda, which really did come with a rack behind the seat for a pizza box, had four punctures, two chain changes and one new drive sprocket during its entire journey. It also survived a shunt from an Argentinean lorry driver who skidded on ice. The accident broke Simon’s right leg but after five weeks’ recuperation he was on his way again, reassured by an apology that it was nothing to do with the war.

Among other gems you learn that Mexicans are among the most courteous people in the world and Columbian traffic police merely act as umpires among the chaos.

“Why would a reasonably sane man in his 70s ride the length of Hispanic America on a small motorcycle?” he asked rhetorically.

“A man who is overweight, suffered two minor heart attacks and has a bad back? Stupidity comes to mind.”

But don’t you ever believe that.

● Old Man on a Bike – a Septuagenerian Odyssey by Simon Gandolfi is published by The Friday Project (HarperCollins) priced £8.99.