A touring bike must be a comfortable, balanced load-carrier with a wide range of gears and robust equipment. Fat tyres and an upright position provide enough comfort to ride all day, day after day. Front and rear panniers allow the rider to carry everything needed for a self-sufficient, multi-day tour, and spread the load evenly over the bike.
Because touring is essentially about personal freedom, and individuals take different things out of the experience, touring bikes are one of the few remaining varieties of bike to employ custom framebuilders in their manufacture. Mass produced touring bikes are available, but a custom built example, made by a specialised framebuilder, can be tailored to individual needs.
This is useful if riders are considering an adventurous tour, and have a good idea of their specific requirements. In a similar way, bikes can be designed to suit the rider's build and riding style, which vary from one rider to another.