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Mountain Hardwear Fluid 18

rated 4.5 of 5 stars
photo: Mountain Hardwear Fluid 18 daypack (under 35l)


Price MSRP: $90.00
Historic Range: $21.73-$110.00
Reviewers Paid: $99.00
Weight 1 lb 12 oz / 780 g
Capacity 1100 cu in / 18 L
Dimensions 21 in X 10 in X 9 in / 53 cm X 27 cm X 24 cm
Materials 100D Ripstop Cordura® Nylon, 210D HexNut™ Ripstop Nylon, 315D Cordura® Nylon


1 review
5-star:   0
4-star:   1
3-star:   0
2-star:   0
1-star:   0

Very lightweight and sleek pack perfect for day hikes, especially in tight bush.


  • Light
  • Comfortable
  • Very sleek design
  • Fits well over bulky clothes


  • Not much room if used to carry a bladder
  • External pocket could have talled sides
  • Bladder pocket has very narrow opening
  • Only 1 small insider zipper pocket

I bought this pack to replace my old Asolo light day pack. I use two different day packs depending on the circumstances, my other is a North Face Terra 40.

This pack is the first one I have tried that is made of the newer, thinner nylon, altough it is still thicker than the thinnest stuff they use.

I have been using this pack weekly for close to 6 months now, although it was bought about a year ago.

My first impression was skepticism. However the girl at the store really loved this bag and swore by it, and since the price was right I thought I would try it out.

The first thing I did was try my 3L bladder in the bag, even though I never hike using one. I immediately discovered that by doing so, there was very little room left in the pack, at least as far as I was concerned. Also the bladder pocket opening is narrow and I had to work to get my 3L in there. A smaller bladder would likely fit better.

When I removed the bladder I set about packing all my typical light day gear—rain gear, toque, buff, overmitts, map, compass, "utility pouch", monocular, and water bottles. Everything fit with lots of room left over for food.

One of my favorite things about this pack is the elastic mesh side pockets. They are very stretchy and durable and they easily and securely hold my 40oz Klean Kanteen bottles. In one side pouch I also have my nesting stainless cup/pot. Even when crashing while cross-country skiing I have never lost a bottle. Because of the material the pockets are made of it also securely holds much smaller bottles.

At first I was worried that they would not last, but they have proven to be very durable. A lot of my hikes do not involve trails. I bushwack my own path to the places I want to go until I get above the tree line. Despite the grabbing tree branches there hasn't even been so much as a snag in the material.

The same however cannot be said for the back pocket/pouch, which secures with three quick release nylon straps. Unless the bag is full, you have to pull the top strap so tight it deforms the pack slightly which you notice when wearing, probably why they changed the design slightly.

The real problem was the sides of the pocket do not extend high enough. Not a problem if using this area to carry your jacket, but normally I have my monocular and snacks in there. I have never lost anything, but care is needed to be sure your items are secure. The side straps to this pocket act as the packs compressions straps as well. The low sides however offer the benefit of cramming extra clothes in.

The sternum strap is adjustable on the fly using vertical slides which are easily adjusted single handed.

The waist belt is very comfortable and also easily adjustable though it only has a 1 1/4" buckle that can be a bit finicky with gloved hands. The belt also has elastic mesh pockets on each side that are very expandable and hold substantially more than you would think by looking at them.

Pack straps are 2 1/4 inch wide of dense foam that is very comfortable even when the pack is loaded to the maximum. Of course they are fully adjustable, and each strap has a D ring, that I find located ever so slightly too high.

This pack does not have an internal frame, instead it has a removable plastic wafer board and a mesh back. I find when I am wearing a shirt only the pack seems to vent fairly well, but once a jacket is added, even a light one I feel it is warmer than my other packs.

The pack holds more than I thought it would and as I said is still comfortable when overloaded. This pack fits extremely well due to its sleek nature and it snugs down really well. I do not run with the bag, but it seems to me that it would feel very secure if I did.

This pack fits very well over my winter gear, and I use it all the time snowshoeing and cross-country skiing as well as hiking, however the waist belt almost runs out of strap with my heavy parka. 

One other negative, the pack has one loop on the bottom and a fixed elastic cord at the top. Unfotunately this elastic cord is useless for holding smaller diameter items such as an ice axe. I have had to attach a piece of paracord to the pack so I could secure my axe using the provided loop.

The pack material is coated and is water resistant, however I reccomend a pack cover or dry bags if hiking in really wet weather.

I highly recommend this pack to anyone who is looking for a light day pack. By "light day" I refer to the type of hike, not the pack itself, though it is very lightweight (no idea what it weighs). With fairly heavy use it has stood up well. I demand durability out of my gear, and I am very impressed with this pack.

I would not reccomend this pack if you want a day pack that is also capable of carrying 3L water bladder, unless you carry way less that I do. The pack does expand well. I just find the bladder really limits the space and packability of the pack.


Source: bought it new
Price Paid: $99 on sale


Thanks for the review, Mike!

6 years ago

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