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#196329 - 08/12/16 11:44 AM Gorilla 40 vs ZPacks Arc Blast vs KS Packs
aistea Offline

Registered: 08/12/16
Posts: 3
Loc: NY
Hi Folks,

I’m in the market for a backpack but need seriously help deciding which one to pick. I have serious back problems as I have two slipped discs in my lower back. So I was thinking that I should have an ultralight backpack that transfers as much load to the waist as possible so that my lower back won’t have to carry that much.

I think I narrowed it down to:

1. GG Gorilla 40 Ultralight Backpack (total 32 ounces) ($245)
a. Plus hip belt

2. ZPacks Arc Blast Backpack (total 23 ounces) ($385)
a. Plus Lumbar Pad
b. Plus two belt pouches

3. KS packs from ks-ultralightgear (total 22 ounces) ($350)
a. 40 Liters dyneema version
b. Plus two belt pockets
c. Plus Internal Pocket
d. Plus Dry bag top closure system
e. Plus Internal pad pocket
f. Plus Anatomic padded hip belt
g. Plus Frame set

They all have a frame and they all claim to transfer lots of load to the hip belt. The advantage of the ZPacks and KS packs is that they’re water proof so in rain they won’t get much heavier unlike the Gorilla which already is 10 ounces’ heavier than the other two. The advantage of the Gorilla is that many reviews claimed that it is ultra comfortable and that it has an excellent load transfer system.

The KS packs had been my first choice until I noticed that the shape of the backpack is completely straight while other framed backpacks (including Gorilla and Zpacks) have all a slight round shape while the Zpacks has even a stronger round shape to a degree that it lets air flow between back and pack. I'm not sure what to think of that.

Which should I buy considering my back issues?

Edited by aistea (08/12/16 11:59 AM)

#196330 - 08/12/16 12:30 PM Re: Gorilla 40 vs ZPacks Arc Blast vs KS Packs [Re: aistea]
OregonMouse Offline

Registered: 02/03/06
Posts: 6524
Loc: Gateway to Columbia Gorge
Actually, the weight should not be transferred to the waist (that is not where the pack belt should rest!) but to the hips. The pack belt should rest on the top of your pelvic girdle. It will put the least stress on your lower spine that way, since the weight resting on your pelvic girdle will go directly to your hip joints. If the pack belt is at your waist, it will definitely concentrate more weight--and twisting--to your lower spine.

Pack fit is almost as individual as shoe fit, so I can't recommend one over the other. I personally need a pack with load lifters that keeps as much weight as possible off my pressure-sensitive shoulders. I also have lower back issues, although not quite as severe as yours.

Should I need to look for a new pack (my current 10-year old pack, a long-discontinued model, is just fine), I would first look at the ULA Circuit or Ohm, or at the Elemental Horizons Kalais. Again, those would be for me, not necessarily for you.

You will need to try each pack with the gear you plan to carry in it (plus the equivalent in bulk and weight of a week's food and a day's water). Have this ready when the pack arrives so you can load up the pack (without removing tags) and try it out (probably indoors) before the time for returns expires, being sure to keep the pack clean and dry. Plan to budget for return shipping--it's worth it to have a properly fitting pack, especially in your case.

I'd also get on the phone with the manufacturers you listed and discuss your specific issues with them. They can give you a lot of advice!
May your trails be crooked, winding, lonesome, dangerous, leading to the most amazing view--E. Abbey

#196332 - 08/12/16 12:38 PM Re: Gorilla 40 vs ZPacks Arc Blast vs KS Packs [Re: OregonMouse]
aistea Offline

Registered: 08/12/16
Posts: 3
Loc: NY
Thank you for clarifying the hip vs waist load transfer issue.

I'll take a look into the companies you recommended. I wish I could just walk into a REI and have all the backpacks available I'd like to buy but unfortunately all of the packs I narrowed down are direct-to-consumer sellers.

#196336 - 08/12/16 07:51 PM Re: Gorilla 40 vs ZPacks Arc Blast vs KS Packs [Re: aistea]
Glenn Roberts Offline

Registered: 12/23/08
Posts: 1510
Loc: Southwest Ohio
To play devil's advocate, I'd like to ask you how much your load for a typical trip weighs, including food and water. One way to get lots of weight off your back, if you haven't already, is to lighten the load by eliminating unnecessary stuff and getting the lightest version you can find of the rest.

Assuming you've already done that, I'll continue along the same contrarian vein: a lighter pack isn't necessarily a better pack for your problem. If you're trying to move weight effectively, a good, functional suspension is more important than minimal weight. I'm not trying to talk you out of a good ultralight pack - and your collection appears to contain several - but, just for the sake of argument, go try on an Osprey Atmos or Aura. Yes, they weigh four pounds, but the weight transfer and general comfort is stupendous, plus the trampoline suspension that keeps the frame off your back, might be worth the extra weight.

When you try them on, you'll be best served by taking the gear (again, including food and water) that you'd carry on a typical trip you'd take. Load it into the packs, and you won't have to guess and estimate whether the pack will carry better or worse than those sandbags the store will try to use. If it's a busy store, call ahead to find out when they're not real busy so you'll have time to get it right without disrupting their business. A good store will let you do this; if they won't, go somewhere else.

I've not had great pack-fitting experiences at REI. The training and expertise of their sales staff is ragged - today, you might get someone who really knows what they're doing; tomorrow, you might get an "expert" who's an expert, but with bikes, not packs. I've had better luck at small outfitters whose staff actually backpack - and I'll buy from them, even if I have to pay a few bucks more, simply because of that expertise.

Good luck. Chances are good that you'll be happiest with an ultralight pack, but try the Atmos/Aura; it really is an unusually functional pack.

#196337 - 08/13/16 07:51 AM Re: Gorilla 40 vs ZPacks Arc Blast vs KS Packs [Re: Glenn Roberts]
bluefish Offline

Registered: 06/05/13
Posts: 678
I wholly agree with Glenn's advice. I went from a 2 lb. pack to an Atmos and all my problems went away. Fit is essential, but the Atmos suspension carries if it's not there. I've used it as a daypack, and it carries lighter than a 1 lb. pack. It may become a weight liability if your pack weight is always under 20 lbs., though. Mine has certainly trended far downward over the decades, but, I still have to carry water into dry camps or multi-days of food on occasion.

#196338 - 08/13/16 09:37 AM Re: Gorilla 40 vs ZPacks Arc Blast vs KS Packs [Re: bluefish]
OregonMouse Offline

Registered: 02/03/06
Posts: 6524
Loc: Gateway to Columbia Gorge
Just to demonstrate that one brand/model does not fit all, every Osprey pack I've tried has been extremely uncomfortable for me. Their hip belts and my hips are definitely not compatible! The result is pain within 5-10 minutes. We are all built differently!

I also have gotten excellent support from much lighter packs. A lot depends on the weight and bulk of the rest of your gear and on how you pack it. Even more, on how the pack with your gear and supplies inside works for you individually.

IMHO, there's no real alternative to trying a number of different packs, with your gear packed inside. Unless, of course, like me, you just happen to luck out with the perfect pack for you being the first one you try!

Edited by OregonMouse (08/13/16 09:41 AM)
May your trails be crooked, winding, lonesome, dangerous, leading to the most amazing view--E. Abbey

#196343 - 08/13/16 01:22 PM Re: Gorilla 40 vs ZPacks Arc Blast vs KS Packs [Re: OregonMouse]
wandering_daisy Offline

Registered: 01/11/06
Posts: 2796
Loc: California
Some packs have interchangeable hip belts. I find that I need an x-small hip belt but a medium (woman's) pack. Ask if you can do this.

I think you need to do more than just load it up with your gear in the store. Take it home, walk around the house for hours. Leave all the tags on the pack so you can return it. I have had packs that fit well at first but after 2 hours on my back, hurt.

I backpack a LOT, and have 2-3 different packs. One pack simply does not do it all. No sense carrying a pack that can carry 50 pounds on a shorter trip. And when I do have to carry 50 pounds I want a really good suspension. I have to do the extra weight when I take out kids or other family members who need help carrying the weight. Also if I do a 14-day trip I need to use my "load hauler"- my old Kelty external frame.

Are you ever going to backpack where you are required to carry a bear can? Many light weight packs do not accommodate a bear can, without it taking up all the space.

If you do a lot of backpacking you will likely end up with several. Nothing wrong with that.

My experience is also that the light weight suspension systems break down over time. So my light packs have to be replaced every 2-3 years or so. I also do a lot of off-trail bushwhacking- very hard on packs. But I look at a pack purchase same as my shoes - if it fits and works, so be it if it wears out in 2 years. I quit buying "bombproof" gear years ago. Usually too heavy and there is so much advancement in design that I really prefer to buy a new pack every 2-5 years. My shoes barely make it one season.

#196379 - 08/18/16 02:03 PM Re: Gorilla 40 vs ZPacks Arc Blast vs KS Packs [Re: wandering_daisy]
aistea Offline

Registered: 08/12/16
Posts: 3
Loc: NY
Thank you for all the response. I'll definitely try out the Osprey backpack. They might just work for me. I'm just afraid that the weight will be too much for me as my doctor and my comfort doesn't allow me carrying more than 20 pounds and having a pack that weights already more than 3 pounds gives me less space for other gear and food.

I'll also follow the advice of all of you and order two packs in my list - the zpacks and GG Gorilla. Unfortunately I'll have to scratch the KS Ultralight as they're located in Japan and returning would be too expensive.

My base weight: 7 pounds (excluding backpack and bear canister)
Weight with water and food: 13-18 pounds, depending on environment and distance to next re-supply location and/or water source.

I'm preparing for my PCT thru-hike attempt next year.

Edited by aistea (08/18/16 02:06 PM)

#196812 - 10/22/16 12:28 AM Re: Gorilla 40 vs ZPacks Arc Blast vs KS Packs [Re: aistea]
Keith Offline

Registered: 01/04/02
Posts: 1666
Loc: Michigan's Upper Peninsula
I have the predecessor to the Zpack Arc series. One of the best packs I've ever had. Pack weight is about 18 oz but it has a good frame that transfers the load and a comfortable hip belt that works.

Another pack I have which weighs a little more but is extremely versatile is the Luxurylite. I have the front pack accessory which makes it possible (to demonstrate the principle of physics) not to use shoulder straps at all. It is probably the best there is at transferring weight to the hips with no weight either on the top or front of the shoulders.
The LL is modular so weight varies according to configuration but approximately 2 lbs. plus or minus. Most ingeniously versatile belt I've ever seen. (Might even work for you OR Mouse).
Human Resources Memo: Floggings will continue until morale improves.


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