For most cyclists, choosing a crash helmet is a bit like choosing a haircut; not so much a triumph of the wallet but a victory for vanity. As any middle-aged pedaller will tell you, the Lycra never lies, but fork out sufficiently for a lid with a few bells and whistles and there's a chance that next time you tackle that monstrous climb on your local high street, you might be mistaken for Lance Armstrong, at least from the neck up.
Britain's Jonathan "Joff" Summerfield had a somewhat less sporting role model in mind when planning his own two-wheeled adventure. "I wanted to look like Michael Caine in Zulu," explains the 39-year-old engineer. After all, he says, if a chap is to pedal a penny-farthing bicycle around the world unsupported, he should at least look the part. Hence the pith helmet that has rarely left Summerfield's head since he set out from Greenwich in London last May.
He is currently on the Australian leg of what, by any standards, is a very grand tour. When we speak on the phone he is resting in Melbourne, the latest destination on a route that has taken him across Central and Eastern Europe and through the Middle East. He is off to Tasmania next, then New Zealand, after which he intends to backtrack to China and Tibet, where he will, he says with utter seriousness, attempt to become the first person to cross the Himalayas on a "penny".
Folk Down Under have grown accustomed recently to Britons travelling by unconventional means. Last week, 26-year-old Dave Cornthwaite from Swansea became the first person to cross the continent on a skateboard, a journey of more than 4,000 miles.
Summerfield is unsure what his eventual mileage will be, but it is certain to be an epic journey. Ten or so years ago, he was enjoying a successful career with a company constructing engines for Formula One cars, machines designed to go rather faster than the 11mph he currently averages on a good day. In 1996 he decided to go freelance and, as a keen cyclist and self-confessed "engineering obsessive", began building penny-farthings in his spare time. He took a stall at Greenwich's craft market and was soon selling his bikes to customers around the world.
With the pennies looking after the pounds, so to speak, he was following a well-ridden trade route stretching back to the 1880s: from the US, where the bikes were known as "highwheelers"; to Australia, which referred to them as "ordinaries", due to the fact they were the first bikes to arrive on the continent.
Given his racing background, it is hardly surprising that Summerfield's own machines are constructed from sterner stuff than the wooden specimens of old. With no frame as such, the single-gear bikes are comprised of a pair monstrous forks made from modern chromoly steel, with a tail, or "backbone", running down to a small rear wheel. Otherwise, insists Summerfield, the machines are true to the original design, new models rolling off the production line at £800 a pop.
Any rouleur worth his bottom bracket will tell you that is more than a fair price for a bespoke, hand-made bike, but there's a reason why what is, after all, an elegant enough looking design enjoyed only fleeting popularity. It was, in short, lethal.
"The most common problem was what the Victorians referred to as 'taking a header'," explains Summerfield. "If the front wheel jams or if you apply too much front brake, the back wheel lifts and the rider follows the arc of the wheel. The first thing to hit the ground is your head, and fatalities were common."
It's a manoeuvre with which Summerfield is painfully familiar and one that might, in one less deter-mined, have been a post-script to his own riding career on numerous occasions. This is his fourth attempt to get round the world on his beloved penny. In 2001, having moved out of his flat, sold his worldly goods and enjoyed a raucous farewell party, he was forced to abort his global expedition with a knee injury - on day one. It was, he says, with hint of understatement, "pretty embarrassing". Two years later, in 2003, an abscess, this time to the other knee, forced him to retire in Budapest.
In 2005, Summerfield decided to test a new version of his bike by riding over a high kerb. "The back wheel came straight up and I broke my elbow and my leg. That delayed me for another year."
Six weeks before this trip, the lamp he uses to navigate at night, which is fixed to the hub of his main wheel, jammed in his spokes - broken wrist, broken arm.
"I probably sound a bit like Captain Calamity," he says. No kidding. More to the point, why persist with the idea of a world tour?
"For me the bike sums up a great period of adventure," he says, "a time of real exploration, of journeys without maps." The Victor-ians, it is worth remembering, were the people who took bone china into the African bush when on safari; the idea that form need follow function is clearly a recent design maxim. Indeed, even a state-of-the-art penny-farthing is so unaero-dynamic, says Summerfield, that in strong winds he frequently has to get off and push, even going downhill.
Mounting and dismount-ing takes place by way of a small step on the backbone, Summerfield explains: "Just scoot along and up you hop." This is a drill that can prove quite wearisome at traffic lights. "You need to time the green," he says. "Either that or lean against a truck."
Next month, he will attend an event considered by enthusiasts as the de facto penny-farthing world championships, the Evandale Village Fair, held annually at Evandale, in Tasmania, for the past 24 years. Summerfield fancies his chances in the 30km road-race event, thanks to a training schedule of 40 miles a day for the past eight months.
Should he make it, he might consider himself lucky to be there at all. While he was riding through Greece last year, high winds caused him to lose his balance on a busy road and he was thrown to the ground, where only his helmet separated his head from the front tyre of an advancing truck.
"The driver thought he'd killed me," he says calmly, "but the only damage was a black streak of rubber on my pith helmet."
Then there was what he refers to as "the Turkish incident". When a shortage of water in the south-east of the country forced him to drink from an agri-cultural irrigation system, he was laid low by a bout of dysentery. Having recovered, he was then forced to accept an escort from a Turkish army unit concerned about the threat from Kurdish separatists who contest Turkish sovereignty in the region.
From New Zealand he will head to Beijing, before which he will need to reacquaint himself with the art of "blagging" his bike aboard a plane. "The key," he says, "is not to call the airline in advance. They think the bike is the size of a house, whereas in fact the seat is only about chest height."
Upon landing, he will, of course, find himself in the world's most populous nation, the majority of whom, so cycle touring lore has it, enjoying travel by bike at precisely the same time.
If, as he hopes, Summerfield is allowed into Tibet some time in June, sur-mounting the Himalayas could take a while. "The highest mountain I've climbed so far is Nemrut Dagi [in Turkey], which stands at around 8,000ft. It took me three days, and the Himalayas are three times the height; it should be interesting."
Nothing like as interesting as the descent, however. To avoid hazardous crashes when going downhill, riders of the Victorian era came up with the rum idea of placing their feet over the handlebars. The idea was that rather than take a header should the bike topple forward, the rider would, in theory at least, hit the ground running. "I found the idea in an old user's manual from the period," says Summerfield. "It also suggested that if you lost control, you should try aiming for a hedge. That or a fat woman."
Summerfield's one regret to date is that, having travelled so far, he missed Cornthwaite "by about 100 yards" after he spotted the skateboarder's support vehicle on a road north of Sydney.
So what do the Aussies make of us Brits conquering their continent by such idiosyncratic means?
"They've been fantastic," says Summerfield. "Probably because it's all the conquering we have been doing lately."
THE COMPACT GUIDE
For the latest news of Joff Summerfield's round-the-world trip, or to make a donation to the Born Free Foundation, the wildlife charity the trip is promoting: pennyfarthingworldtour.com. The National Penny Farthing Championships will be held at Evandale in Tasmania on 24 February. For race schedules and more information: evandalevillagefair.com