Should I get a backpack with wheels?

Generally, no. Wheels add significant weight and take up internal space. They are also useless on cobblestone streets or dirt paths, which you will inevitably encounter.

Is 60 liters too big?

Yes. If you fill 60 liters, you will likely exceed airline carry-on weight limits and find it difficult to move through crowded public transit.

Choosing the Right Backpack for Long-Term Travel

Prioritize a backpack between 40 and 50 liters that opens like a suitcase rather than a top-loader. Ensure it has a dedicated hip belt to transfer weight off your shoulders, and always test it with weight before committing to a purchase.

Measure your torso length. Don't measure your height. Measure the distance from your C7 vertebrae (the bony bump at the base of your neck) to your iliac crest (the top of your hip bone). Match this measurement to the manufacturer's size chart.
Select a clamshell-style opening. Avoid top-loading hiking packs. For long-term travel, you need a bag that zips open fully like a suitcase so you can access items at the bottom without dumping everything out.
Confirm carry-on compatibility. Aim for dimensions around 22" x 14" x 9". This allows you to bypass checked-baggage fees and eliminates the risk of an airline losing your gear.
Test with actual weight. Go to an outdoor store, load the bag with 15-20 pounds of sandbags, and walk around the store for at least 20 minutes. If the weight pulls your shoulders back or feels uneven on your hips, try a different model.

Should I get a backpack with wheels?: Generally, no. Wheels add significant weight and take up internal space. They are also useless on cobblestone streets or dirt paths, which you will inevitably encounter.
Is 60 liters too big?: Yes. If you fill 60 liters, you will likely exceed airline carry-on weight limits and find it difficult to move through crowded public transit.