At the risk of sounding oldschool and upsetting some die-hard enduro bikers with hipbags: You won't get far on a proper bike tour without a proper backpack. And, even if the sporting goods industry overdoes it with many super special products (keyword: Speek Hiking), getting a backpack specifically for biking makes sense.
Unlike the hiking backpack with good ventilation, this one should fit close to the back, which also serves as protection for the spine. There are already some products with integrated back protectors on the market, but you should make sure that the length of the backpack fits your upper body. In addition, a biker backpack should not slide back and forth, this is ensured by a wide hip belt with a good closure system. A separate compartment for tools and repair utensils also proves to be very useful. Then there are features such as a goggle compartment, side pockets, helmet or protector holder - which are indispensable for one biker, but don't matter at all for another.
