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Mountainsmith Mayhem 35L Backpack Review

Mountainsmith Mayhem 35L Winter Backpack

The Mountainsmith Mayhem 35L backpack is a great winter and climbing backpack, well-suited for day-long hikes that require carrying heavy winter gear such as snowshoes, skis, a snowboard, an ice axe, and avalanche shovel. A top-loading pack, it has numerous external attachment points for lashing gear to the outside of the pack in addition to side water bottle pockets and a rear shovel pocket.

Mountainsmith updated this pack in 2019 with new Specra Ripstop. See the Mountainsmith Mayhem 30.
The Mountainsmith Mayhem 35L backpack has a top lid that secures to the pack body with a single strap.
The Mountainsmith Mayhem 35L backpack has a top lid that secures to the pack body with a single strap

Internal Storage and Organization

The Mayhem has two pockets, a large main compartment including a hydration pocket, and a large front-facing zippered pocket in the top lid. The main compartment has a small 6L extension collar and closes with a drawstring, but the pack does not have a piece of webbing under the lid to secure a rope, like many larger climbing packs. If you want to carry one, your best bet is to secure it sideways under the top lid and lash it down using the pack’s side compression straps.

The top lid pocket is quite large and sufficient to carry navigational equipment, maps, food, and extra gloves that you need during the day. The inside of the pocket is lined with yellow fabric making it easy to see items stored in it and contains a clip for car keys or other items you may want to secure.

The Mayhem 35L has an open shovel pocket with a small zippered accessory pocket for storing soft items like extra gloves or hats.
The Mayhem 35L has an open shovel pocket with a small zippered accessory pocket for storing soft items like extra gloves or hats.

The Mayhem also has a front shovel pocket for securing loose clothing and gear, with an external zippered pocket for storing soft items, like gloves, extra hats, or a map. The shovel pocket is closed with mesh along the sides, which limits its capacity but also prevents items from unexpectedly falling out.

The Mayhem comes with two side mesh bottle pockets that are large enough to store 1 liter Nalgene water bottles, although the fit is tight if they’re wrapped in water bottle insulators. It also has two mesh pockets on the outside of the hip belt, that can be used to store snacks, but you wouldn’t want to use them to hold anything precious because they don’t close on top.

The Mayhem 35's side compression straps are reversible so it is possible to lash snowshoes or a board to the back of the backpack
The Mayhem 35’s side compression straps are reversible so it is possible to lash snowshoes or a board to the back of the backpack

External Attachment Points

The Mountainsmith Mayhem 35L excels as a gear hauler with numerous external attachments for carrying awkwardly sized winter gear. For example, with two tiers of compression straps, the Mayhem can carry bulky snowshoes along the sides of the pack or lashed over the shovel pocket using its reversible webbing straps. If you have snowshoes with bindings the collapse flat, you can even carry your snowshoes in the shovel pocket, as shown below.

Mountainsmith Mayhem 35L Backpack - Rear Shovel Pocket can be used to stow snowshoes or an avy shovel.
Mountainsmith Mayhem 35L Backpack – Rear Shovel Pocket can be used to stow snowshoes or an avalanche shovel.

The Mayhem has an extra daisy chain on the outside of the shovel pocket that you can secure more to, like microspikes, using a carabiner. You can also stow the tips of trekking poles in the little yellow loops at the bottom of the shovel pocket and lash your poles to the outside of the pack or carry an ice axe using the removable ice axe loop and dual shaft holders provided.

With all this gear lashed to the outside of the pack, you’d think that the Mayhem 35L would be awkward to carry, but that’s not the case at all. The pack body is shallow and narrow enough that you don’t feel the backward pull of heavy gear, even when the pack is fully loaded with a day’s worth of food, water, and extra insulation layers. Seriously, the ease of carrying external winter gear makes this pack special.

The back of the Mountainsmith Mayhem 35L backpack is heavily padded with an central air channel to help vent perspiration.
The back of the Mountainsmith Mayhem 35L backpack is heavily padded with a central air channel to help vent perspiration.

Suspension System

While the Mountainsmith Mayhem 35L backpack can be considered an internal frame day pack, it has a very simple suspension system built around a non-removable, rigid plastic sheet tightly sewn into the back of the pack. Extra rigidity, which translates into better load to hip transfer, is provided by heavy padding that runs down the sides of the back, terminating in a thick lumbar pad that rests on the top of your tailbone. The lumbar pad is a signature element on Mountainsmith packs and a carryover of the company’s expertise in making bomber lumbar (fanny) packs.

Conversely, the Mayhem’s hip belt is completely unpadded, so that it wraps around the natural shape of your hips, preventing slippage, especially when worn over outer winter layers. The hip belt, which is over 4.5″ wide, pulls the rear lumbar pad closer to your core where most of the pack’s weight is carried while providing a comfortable form-fitting, unisex fit.

The Mountainsmith Mayhem's hip belt is unpadded and can be tucked behind the lumbar pad enabling use of the pack with a climbing harness.
The Mayhem’s hip belt is unpadded and can be tucked behind the lumbar pad enabling use of the pack with a climbing harness.

The hip belt on the Mayhem can also be tucked behind the lumbar pads, allowing the pack to be used with a harness, which is a very nice feature, especially for ice climbers.

Recommendation

The Mountainsmith Mayhem 35L backpack is an excellent winter pack for snowshoeing, peak-bagging, ice climbing, snowboarding, and backcountry skiing. Sized for day trips, the Mayhem is capable of hauling all of the food, water, and gear you need to carry for backcountry adventures with highly functional internal storage and a flexible and easy-to-use external attachment system. The use of lightweight fabrics coupled with a comfortable suspension system makes this a durable pack that is comfortable to carry and made to last.

Likes

  • Reversible compression straps let you attach gear to the rear of the pack, in addition to the sides
  • A very comfortable carry with awkward and heavy winter gear
  • Suitable for a wide variety of winter sports, including 3 season use as a regular day pack

Dislikes

  • Load lifter straps are excessively short and nonfunctional
  • The side mesh pockets are a bit small for carrying 1 liter bottles with winter insulation covers
  • I’d rather have gear loops on the hip belt than open mesh pockets

Manufacturer Specs

  • PE frame sheet load dispersion with lumbar pad
  • Tuck away waist belt
  • Air mesh back panel with perspiration control system
  • Load lifter straps
  • Ski & Snowboard Carry
  • Front panel pocket
  • Side panel mesh pockets
  • Avalanche shovel pocket
  • Tool / Trekking pole carry
  • Storm collar (6L capacity)
  • Materials:
    • 210d Duramax™ Junior RipStop Nylon
    • 420d Duramax™ Nylon
    • 210d RipStop Liner
  • Fit Range: Torso: 16″ – 21″ (40.5 – 53.5 cm)
  • Weight: 2 lbs 5 oz / 1.04 kg (verified on SectionHiker scale)
  • Capacity: Up to 45 lbs (wishful….more like 30 lbs)
  • Volume: 2135 cubic inches / 35 L
  • Extended Volume: 2500 cubic inches / 41 L
  • Dimensions: 22″ x 11″ x 7″ / 55.75 x 28 x 17.75 cm

Disclosure: Mountainsmith provided Philip Werner (SectionHiker.com) with a sample Mayhem 35L backpack for this review. 

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10 comments

  1. Looks like a great winter pack. Is there any way to attach a biner to the hip belt, say to hang a water bottle?

    • There’s a small span of webbing on the hip belt next to the buckle that you can clip a biner onto, but it means that your water bottle will swing and hit you in an awkward spot. Follow me? So I wouldn’t recommend it.

  2. Hi Phil. I like the look of the pack. My concern (which you mentioned) is with the size of the side mesh pockets. I have the OR water bottle insulators (fairly bulky) that fit a 1L Nalgene. Do you think I could get them into the side mesh pockets?

  3. Thanks, Phil. Yes, that really is a shame. I’ve been looking for a good all around winter day pack and I think this one would have fit the bill with larger side mesh pockets. Maybe I’ll consider putting them in the pack like you do. BTW, can you reach your water bottles w/o taking off this pack? Sometimes I can’t. If that’s the case, it would take the sting out of storing the bottles inside, since the pack would come off anyway.

  4. Have you used this pack much since the review? My current day pack is beat up and I’ve been doing a lot of searching for a large hauling day pack. This is one of my narrowed-down choices. Some of your Dislikes I probably wouldn’t worry about since I’m in NC and I don’t need insulated bottles or excessive attachment points for winter gear. The Mystery Ranch Scree 32 was also intriguing, but this seems like a more versatile day pack. It’s hard finding 30-40L day packs with shoulder strap daisy chains, which is one of my top filters because currently I attach camera pouch with tri-glides, GPS with carabiner, and SPOT with tri-glides (if I’m using it).

    • This one is long gone, and they’ve since changed the design. But I hear you loud and clear regarding shoulder strap daisy chains. I use them too. The scree is not a bad pack. I gave my pack to a friend who’s a mountaineering guide and he really loves it. It has a quite burly frame, so good for weight.

      • Yeah I think they added the diagonal water bottle pocket and added two different hip belt pockets compared to this review. All of which I like. I might simply prefer the Mayhem which is $40 cheaper and I like the down the side zipper opening better than the three-prong Scree zipper. The other one I found that has similar features is the Granite Gear Lutsen 35, which is actually on sale at a few sites for a good price. But your 55L review kinda scares me off from that, mainly the lumbar pad.

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