Oh, and I'm covered in a fine red dust, kicked up by those growling trucks, and have crash-helmet hair and a bug stuck in the corner of an eye. I'm also nursing an icy cold Beer Lao. I'm in pleasant, like-minded company, a hot shower awaits, and the Ou River, an emerald-green tributary of the mighty Mekong, gurgles below us and through the dramatic karst landscape that looms all around. I couldn't be happier.

Four of us are in the hands of Willem Vermeulen, the Dutchman who heads up Corner Adventures (corneradventures. com), which operates motorcycle tours out of Xishuangbanna, in the exotic subtropical south of Yunnan, and bustling Siem Reap - the primary access point for wonder-of-the-world Angkor Wat - in Cambodia.

We set off on a Sunday morning from Xishuangbanna. Though champing at the bit, intrepid Vermeulen resisted any urge to race off into the wild and cerulean yonder while his less-experienced charges familiarised themselves with their powerful 600cc Jialing motorbikes (two with sidecars - handy for heavy luggage). The Jialings are today's rugged China-made steeds of choice for the People's Liberation Army.

Though only 25 years old, Hong Kong-born Vermeulen has been riding powerful bikes since … well, since he was allowed to (and probably before). In 2011, he rode a Chinese Chang Jiang 750cc motorcycle from Shanghai to Amsterdam. His 17,000km adventure took 90 days and passed through 19 countries. He has also taken a Jialing through Tibet and to Everest Base Camp.

The G213 highway to the border with Laos was - as is typical of China's major road infrastructure in 2015 - as smooth as polished glass, and so the 200km ride was largely uneventful. We did get pulled over by police, but only so they could admire the Jialings and take selfies with their smartphones.

Having crossed into Laos at Mohan Port, the riding changed dramatically; the terrain gradually became more craggy and picturesque, and the route riddled with potholes, swooping curls and hair-raising switchbacks. After a night in Luang Namtha, the one-horse-town gateway for hill-tribe treks in the Nam Ha National Protected Area, we made it intact to charming Nong Khiaw - and that cold beer.

At this point, it should be admitted that motorcycling through Indochina is not all deprivation and grime. As well as the much-heralded sense of freedom (it's a cliché, but so, so true), there are moments of sybaritic indulgence. We are comfortably ensconced in the Mandala Ou, a manicured garden resort with 10 stylish detached bungalows (and Nong Khiaw's only swimming pool - an infinity model at that - which overlooks the river).

Intriguingly, many canary yellow, orange and neon-pink blooms in the garden burst forth from rusting metal semi-cylinders measuring perhaps a metre and a half in length. They are jungle-salvaged bomb casings, grisly souvenirs of the Vietnam war, which turned unfortunate Laos into the most bombed country per capita on the planet (the United States dropped more than 270 million shells into the Buddhist nation in a CIA-run operation aimed at destroying North Vietnamese supply routes).

Back on the bikes the following day, we make for Phonsavan and the Plain of Jars. The Laotian equivalent of Britain's Stonehenge, the archaeologically puzzling plain is an expansive grassy area littered with enormous, 2,000-year-old stone vessels, some close to three metres tall and weighing tonnes. Nobody truly knows what they are, and while some Indiana Jones types believe their purpose may have been burial-related, local legend says a tribe of warlike giants used them as wine goblets to celebrate a great victory.

Day four and we point the Jialings in the direction of notorious Vang Vieng, which not so long ago was the hedonistic party capital of Southeast Asia, awash with noisy bars and inebriated young travellers, more than a few of whom drowned in the adjacent Nam Song River.

The 230km ride to Vang Vieng is a joy, and undoubtedly a highlight of the journey, winding through sheer-sided karst mountains that could have been lifted straight out of , and which stretch violet-tinted to the horizon. The roar of our engines announces our presence long before we reach each of the many stilted wooden villages along the way. As we pass through, entire communities, the apple-cheeked children first, race to the side of the road to shout encouragement, to wave and beam with delight. It's impossible not to grin from ear to ear, always at the risk of catching more bugs in the teeth.

In 2012, a government clampdown reined in Vang Vieng's excesses, and today, while still attracting adventurous globetrotters with opportunities for river kayaking, swimming and tubing, it's a significantly more sedate destination, and ideal for a day off the road.

SEE ALSO: Riding Thailand's Mae Hong Son Loop

Soaking up the sun's rays at the lazy river's edge, the painful cold of the northern mountains is now a fuzzy memory (but also a self-indulgent bragging opportunity, banked for later). The rest of the adventure will take us through significantly flatter, rice-growing terrain, racing over the Mekong into Thailand on the monumental Friendship Bridge, which links the two countries, slicing through Thailand's northeastern Isaan region before crossing into Cambodia and rounding up at Angkor Wat. All in all, we will have covered close to 2,000km.

With a rainbow-patterned hot-air balloon sluggishly floating over the Nam Song, another Beer Lao in hand and flamboyant songbirds trilling in the frangipani and bougainvillea branches, I swear I can also smell bergamot, geranium and lavender.