A touring bicycle is a bicycle designed or modified to handle bicycle touring. To make the bikes sufficiently robust, comfortable and capable of carrying heavy loads, special features may include a long wheelbase (for ride comfort and to avoid pedal-to-luggage conflicts), formerly frame materials that favour flexibility over rigidity (for ride comfort. Frame flexing can lead to metal fatigue and frame failure so newer frames are rigid), heavy duty wheels (for load capacity), and multiple mounting points (for luggage racks, fenders, and bottle cages).
Touring bicycle configurations are highly variable and may include road, sport/touring, trail, recumbent, or tandem configurations.
Road touring bicycles have a frame geometry designed to provide a comfortable ride and stable, predictable handling when laden with baggage, provisions for the attachment of fenders and mounting points for carrier racks and panniers.
Modern road tourers may employ 700C (622 mm) wheels — the same diameter as a road (racing) bicycle. Other road touring bikes may feature wider rims and more clearance in the frame for wider bicycle tires. Before the 1980s, many touring bikes for the North American market were built with 27-inch (630 mm) wheels which have a slightly larger diameter.
Other touring bikes use 26-inch wheels for both off-road and on-road use. Advantages of the slightly smaller wheel include additional strength, worldwide tire availability, and lighter weight. Some touring bicycles, such as the Rivendell Atlantis and Surly Long Haul Trucker, offer frames designed for 26-inch (ISO 559) wheels or for 700C wheels, with the frame geometry optimal for the selected wheel size. Specially made touring tires for 26-inch wheels are now widely available, especially in developing countries, where 700C may be difficult to obtain. Hence, on the mass ride from Paris to the Beijing Olympics in 2008, the Fédération Française de Cyclotourisme asked all riders to use 26-inch wheels.