Initially I thought the advertisement was a joke: "Ride on the Roof of the World with Travel Directors," it proclaimed. "Cross the Himalayan Plateau from Lhasa to Kathmandu on a Royal Enfield Bullet." An extraordinary proposition but, as it turned out, a serious one and for me it proved to be the adventure of a lifetime.
Even before we had been acquainted with our trusty bikes the thrills were there, courtesy of the Himalayan Express - the world's highest railway - which took us on an exhilarating two-day journey from Beijing to Lhasa. Cocooned in our specially oxygenated train, we gazed in wonder at a bewildering array of landscapes. As we neared the Tibetan capital the majestic snow-capped peaks of the Himalayas unveiled themselves and we realised that very soon we would be riding among these great mountains.
As if the famous Potala Palace wasn't a spectacular enough backdrop, on arriving at our hotel we were greeted by the sight of 26 Bullets lined up and ready. These iconic single-cylinder motorbikes are still manufactured in India and, like excited schoolchildren, we piled off the bus to inspect our mounts for the nine-day ride.
We spent three days in Lhasa, acclimatising to the rarefied air and familiarising ourselves with these terrific machines.
With the superb Brahmaputra Grand Hotel as our base we rode around this intriguing city, visiting the summer palace, from where the Dalai Lama escaped into exile in 1959, and the Sera Monastery, where the monks debate with each other in extraordinary fashion: shouting and gesticulating wildly.
Now it was time for the real adventure as we set out on the 1000km-ride across the Himalayan Plateau, through the heart of Tibet. The first leg took us to the medieval town of Gyangtse. It was a dramatic first day, the road winding up and around the mountains to the Kampa La Pass at an altitude of 4794m.. The views across the sparkling blue Yamdruk Lake were breathtaking. Much to our amazement, we were treated to a superb outdoor lunch on tables bedecked with white cloths. A couple of yaks looked on as this strange mob of leather-clad bikers tucked in.
We then climbed to another, even higher, pass at 5020m. With the sun reflecting in the lake waters below, life felt very, very good.
The second day's ride, from Gyangtse to Tibet's second-largest city, Shigatse, was a breeze; a 90km run through flatter farmland where families toiled using primitive wooden yak-drawn ploughs. Apart from a few four-wheel-drive cars, the only other "vehicles" we encountered were horse and carts.
Day three was to test our resilience: a 232km ride to Tingri, a remote settlement within striking distance of Everest base camp on the mysterious north face. To get there we had to climb into the heavens once more, reaching the famed Lhakpa La Pass at 6849m.
The following day was to be a big ride on unsealed roads to base camp. But information from other riders suggested the surface was in poor condition and suitable only for the most experienced.
Just one of our group made the effort, the rest of us travelling in 4WDs to the great mountain. The "Roof of the World" must surely be one of the most awesome sights on Earth. We ate another delicious lunch while gazing at the peak, knowing at that very moment brave climbers were "attacking" the summit.
Our lone rider arrived, unscathed but exhausted, so I offered to ride his bike back. The Enfield performed beautifully and I felt almost euphoric as I followed the snaking rough road down to our hotel in Tingri. It was a day none of us will ever forget.
From Tingri we enjoyed another exhilarating day. The 244km ride to the border town of Zhangmu saw us descend an astonishing 2300m, from snow-capped mountains to a fertile green valley. Suddenly our lungs were again full of oxygen-enriched air, our heads were clear and the thought that Kathmandu was only a day's ride away gave us renewed energy.
Our final ride, into the chaotic capital of Nepal, was slow but unforgettable. We jostled with trucks, buses, taxis and animals. The noise was deafening but, again, it was a unique experience.
Finally, triumphantly, we rode on to the forecourt of our central hotel before hugging each other, slapping backs and congratulating new-made friends on our ride to the Roof of the World.
We partied hard that night, planning our next adventure, but there was an air of sadness the following morning when we farewelled our trusty Enfields.
However, we did squeeze in one final ride as we delivered the machines back to their depot.
>> Mike Bennett was on Travel Directors' Ride on the Roof of the World escorted motorcycle tour. Next year's adventures depart Perth on May 13 and October 7. The company also runs motorcycle tours through Siberia, Mongolia and China, and east Africa next year. Call 1300 856 661 or see www.traveldirectors.com.au .