Packing backpack 50 lt for one 8 days in NZ.

exchange it, comes down to how bulky your gear is and that varies between person to person, you'd have to have the right gear to start with to fit it all in.better a pack thats too big than too small, more flexibility on the size of tramps you can do with a bigger pack

What waynowski says: too small is worse than a heavier pack. Get that 65 litre.

ditto. I downsized from a monster 85 litre to a 65 litre and I can fit @ 8 days worth of tramping gear/food. 50 litre is pretty small but it could work for a Great Walk in that you won't need a stove/fuel, tent, sleeping pad. You'll be down to the essentials but that's not a bad thing, either. Another option is to take a day pack for your extra stuff you don't need for the tramp and chuck it in a locker in Glenorchy/Q'town while you complete your tramp.

I know people that do it but really you are down to basics and no contingency plan. You need to think of items like a sleeping bag small enough to wrap your hand round 800 loft down jackets in summer weight etc. Im not the person to advise. I use a 35l pack as a day pack and sometimes its full. 65l I could do just. 50l not even for an overnighter

Yes got it...For sure just for the routeburn track a 50 lt would be totally fine but because I'm tramping around 4 days before the start of the routeburn I realize that even if I want to put extra undies or base layer I reach almost the top straight away... I might go to the store with all my essentials and have a try there...might look stupid or crazy but when you spend over 200 $ for a backpack you want make sure that everything it's at right place. I was thinking that another idea is that I can put my sleeping bag hanging down outside...but I need to get a rain cover just for that...

Definitely doable, I am using a 44L backpack and my partner a 39L and we can fit 8+ days of food in them (I reckon about 10 days would be the max), including tents, +5°C sleeping bags, mats, stove, etc. You just have to be organised and have adequate gear. I used to have a sleeping bag that took half of my old 60 litres pack, add the tent and my bag was full and I had to strap the food and mat on the outside. Not fun. Now my sleeping bag is a lightweight quilt and small as a can of baked beans. And it is performing much better than the big one. So yeah it can be done, easily and cheaply (my whole tramping gear is worth less than $400, including the tent), but it takes time and experience to learn what suits you best. And if you begin with a smallish pack like a 50 litres, you might not have the suitable gear that will allow you to pack enough food for your trip. Usually the rule is to get the backpack in last, after you have all your other stuff, so trying it in the store is not that crazy, just common sense. And for your sleeping bag I would treat it as your most important piece of gear, you don't want to have a wet sleeping bag after a day tramping in the rain. And it's also very important to keep it dry if you are stranded in the bush. Personally I use a dedicated dry bag to put all my sleeping stuff: thermals, mat and sleeping bag.

It still remains that you can make a big bag smaller but you can't make a small bag bigger. The difference in weight between a 50l and a 65l bag is negligible.

If you break your leg, a sleeping pad of some sort would come in handy as hyperthermia and a fractured femur are serious enough to transfer a patient to a main big city ICU for management.

Yep, go to the store with all your stuff and really try out the packs. You would be surprised. We do that too, I doubt it's unusual, but definitely highly recommended.