Setting off by motorbike is a bold but easy decision to make. However, be under no illusions as to the monumental preparation required and the sacrifices needed for two-wheeled life on the road. Chief amongst these is a bike's limited ability to carry little more than essentials. Documentation for bikes is identical to that needed for cars, and one should always carry copies. The cost of a carnet de passage is one good reason not to take an expensive bike, the fact that a long journey will annihilate its resale value is another. Inexpensive bikes, well prepared, are the best way to go.

Before you go

Taking the UK as a departure point, two of the most popular itineraries are trips across Africa to Cape Town or across Europe and western Asia to India and beyond. Both routes are frequently undertaken by bikers. Africa, with its unavoidable desert and jungle is the harder of the two, a challenge of arduous terrain and tedious border crossings.

Before undertaking these big trips, you should consider taking an exploratory run, to Morocco, for example, to see how your bike will perform. Much can be learned on a test run, above all from the shock of finding out how your bike actually handles when fully loaded on dirt roads. Allow at least a year for preparation before starting your trip - and for finding your funding. A good place to start researching routes on the internet is www.adventure- motorcycling.com, which features over 100 trip reports from all around the world. Trans-Africa will cost about £4,000, plus the cost of your bike; India and back about £5,000 and round the world around £10,000, depending on your route and resistance to temptations.

When it comes to getting your bike to your starting point, remember that while shipping is cheap, it is also slow and unnecessarily complicated; air freight is much more efficient and reliable. Leave some money at home with a reliable friend, or a credit card number with a friendly bike shop, that way vital items can be quickly despatched with just one call.

Choosing a bike

A four-stroke, single-cylinder trail bike of around 600 cc is best for Africa. For the main overland route to India any road bike will do and, in this case, a big, comfortable, shaft-driven tourer makes a lot of sense. Road bikes will limit your ability to explore off the highway and are exhausting when you have to detour off- road, but they are a better option for passengers. Whatever bike you choose, consider these factors along with the total weight once loaded:

1.Lightness

2.Economy

3.Comfort

4.Mechanical simplicity

5.Agility

6.Reliability

7.Robustness

Once the most popular bike was Yamaha's XT600 Ténéré; pre-1989 models are best, being simpler, lighter and more economical to run, but these are now hard to find. BMWs are also famously popular, but stick to the old Boxer-engined models of between 800 and 1,000cc or the F650 Funduro. Suzuki DRs (especially the new 400) and the bigger Honda XLs are also good, particularly the XL650R, but avoid XRs, Yamaha TTs and other enduro-type bikes, which are not built for the rigours of long-distance touring. KTM's 640 cc Adventure is, in some ways, an ideal bike - it has a huge tank and a bias towards off-roading, but at the cost of an uncomfortably narrow seat. Women or short-legged men might find lower-seated 350/400s easier to manage.

Bike modifications and tyres

If you're buying a bike, go for one with a big tank (i.e. at least 20 litres): this will solve a lot of logistical problems. Jerrycans are awkward to carry, but may be essential for a desert crossing. Water-cooled engines offer unnecessary complication, but oil coolers can be a useful addition in hot climates. Other tips are to get hold of a bigger footplate for your sidestand to support the bike on soft ground and to fit Barkbuster handlebar lever protectors and security bolts (rim locks) on wheel rims. Use only top-quality O-ring chains (DID or Regina) with wheel sprockets (the manufacturers' originals are often the best). You are inviting trouble if you use cheap transmission and rolling components. DID, Excel or Akront rims, laced with heavy-duty spokes, are a good precaution for rough roads and heavy loads. Paper element in-line fuel filters are another wise modification, and if you don't trust foreign motor oil, change it every 3,000 km or so. Replace cosmetic, plastic sump guards with proper alloy bash plates. Carry a tool for every fitting on your bike, plus duct tape, wire and glue. Modern bikes (especially the ones recommended) are incredibly reliable, and so spares are up to you, but at least carry heavy-duty inner tubes, control levers and anything else that is likely to wear out or break before you can replace it.

Tyre choice is always a quandary. To cross Africa, run down to the Sahara on any old tyre and then fit Michelin Deserts, extremely tough desert racing knobblies that will last well beyond the mudbath of Zaire with barely a puncture. Less expensive, though not quite as tough, are Pirelli MT21s, an excellent road/dirt compromise. In sand or mud, knobbly tyres make the difference between constant slithering and prangs or sure-footed fun. If you're heading across Asia or round the world on roads, pick the longest-wearing rubber you can buy. Tubeless radial tyres are relatively new to overlanding, but last a long time and can be easily repaired on the wheel with plugs and glue, plus a pump or carbon dioxide cartridges. Even then, you must be completely at ease with tyre removal and repairs, the most common cause of breakdown - unless you choose to buy an Enfield Bullet in India. If this is the case, go for the 350 cc model and expect to meet many roadside mechanics. One overlander described her Bullet as being "always sick but never terminal".

Luggage and clothing

Overloading is the single most common mistake, but something to be avoided if your bike is to be manageable off the road. Every biking overlander ends up giving stuff away or sending it home. Although German bikers love their huge aluminium boxes, the only advantage of this system is security and neatness. Soft throw-over panniers in either tough woven nylon, ex-army canvas bags or rucksacks, or simply home-made leather bags are lighter, cheaper, crashable, repairable and not prone to fracture or inflict painful injury. They will not be water-, dust- or theft-proof, but if you keep your baggage nice and dirty no one will want to go near it. Small tank bags are also very handy for valuables, but Krauser- or Givi-type boxes will eventually break on your average Afro-Asian road. Bear in mind that widely loaded bikes use more fuel and, in all cases, pack heavy weights low and towards the centre of the bike. Bulky, light items such as sleeping bags can be carried high, even over the headlight, but tools are best stored in an old ammo box or pouch attached to the bash plate. Carry fuel in steel jerrycans, which also make useful bike props and stools and are resellable anywhere. Above all, think light: non-bike stuff can be replenished or replaced on the way.

Your choice of clothing is limited only by its usefulness and durability. You will only wear one jacket, so make sure it can protect you from the rain, wind, stones and crashes. Natural fibres are light and comfy, leather can be heavy and hot and takes ages to dry. Top-quality touring jackets, such as those produced by Hein Gericke, are expensive, but are also light, robust and functional. The merits of breathable fabrics such as Gore-Tex are dubious on a bike, but lots of big, secure pockets are very useful; use your jacket like a wallet or safe and never lose sight of it.

Helmet choice is personal, but remember that an open-faced one makes you appear more human to strangers. Always wear goggles or use a visor. Stout footwear will protect your vulnerable legs; proper motocross boots are best for off-road trips, otherwise ex-army boots will last.

Life on the road

Pull over from the roadside and camp out of sight of passing vehicles. Never ride at night or miss a chance to fill up with fuel and water. Be aware of you and your bike's limitations when driving off-road, especially in the early days when you have yet to learn the benefits of less baggage. Even if you are a loner, you will find yourself delighted to team up with other overlanders when faced with remote or dangerous sections of your trip, such as when crossing the Sahara or Baluchistan. The longer you travel, the lighter and more refined your equipment will become.

Resist the temptation to ride and ride and ride. Whatever your stated goal, it's the people you will meet on the road that will provide the longest memories, both good and, sometimes, if they are in uniform, bad.

Traditionally capricious, border guards are generally easy on bikers, recognising that two-wheel overlanding is no picnic. Nevertheless, approach a border as if you were going to be there for days. Bribes are usually small and clearly prompted, unless you are in trouble. If there is one common piece of advice most overlanding motorbikers come back with it is this: plan well but trust your ingenuity. Everything works out all right in the end.