Lockable Zippers

Do most internal frame backpacks have lockable zippers? That is, little hoops in each zipper so that when they come together you can throw a lock through them. Just wondering practibility wise for possible European/S.American backpacking.

I'm not really sure that the locking feature would help much against someone with a knife handy. Sort of in the same league as locking the doors on a convertable auto.

Short answer is no. As Pika said, it is so easy to slice into a pack with a knife that a lockable zipper is useless. But why do you ask? There are several solutions, depending on your need. If it is the airline travel and checked baggage you are asking about, I put the pack in a heavy-duty duffel that has zippers that can take a TSA lock (TSA will cut the lock off if they want to inspect the bag and don't have an easy way in). In the past couple of years, I have used a roll-around duffel for this. Packs not in duffels tend to have their straps caught in the conveyor belts, which can rip the bag open. The one I have (discontinued model from Eagle Creek) has tuck-away straps that allow it to be carried like a pack, but I mostly roll it around in the airports or when running for the Metro.

If you are concerned about having someone get in the bag while checked, left in a hotel room, or while your back is turned at the bus stop, then consider the PacSafe steel cable mesh net that fits around the bag and can be locked with just about any lock. This prevents someone from unzipping and taking large items, although they could still unzip or cut and take items small enough to fit through the holes in the mesh (2-3 inches in size).

For flying, once TSA is done with your bag, use zip ties or mini-locks. This keeps the bag closed until you recover it. If you use zip ties, you will know if someone has cut it off. If so, look immediately for missing items. Some claims have to be made right at the airport and the missing tie will alert you to the problem before you leave the terminal. You can pick up a pack of small zip ties at Radio Shack for a couple of bucks.

The tie-wraps don't help for checked luggage. I have had my climbing duffel inspected on several flights (I have indicator locks that show a red dot if opened, plus they leave a printed notice in the bag). The inspection is done after the bag disappears down the check-in conveyor