Less Risks of damage: Unlike a suitcase, a light weight backpack wont tend to have any moving parts (apart from zips) This means you are automatically limiting the risk of damage to your luggage/ I.e broken wheels on cobbled streets etc. When interrailing, you're going to be on the move quite a lot.

For an Interrail trip in 2026, a high-quality backpack is significantly better than a suitcase. European travel often involves navigating narrow train aisles, sprinting between platforms for tight connections, and walking over historic cobblestone streets that can destroy the wheels of a standard suitcase. A 40L to 55L backpack allows you to keep your hands free and move quickly through crowded stations. It also makes it easier to climb the stairs in older European hostels and hotels that may not have elevators. If you are worried about organization, using packing cubes inside the backpack is the "game-changer" tip for 2026—it keeps your clothes compressed and easy to find without emptying the whole bag. While a wheeled suitcase might be easier on your back while standing in a flat airport terminal, the sheer physical logistics of a multi-city rail journey across Europe make the "wearable" mobility of a backpack the far superior and less stressful choice for a month-long adventure.