Worth consideration: Flex Capacitor Pack named “Top Gear Pick” of 2016 by Gear Junkie


Last week Gear Junkie named the Sierra Designs Flex Capacitor 40-60 Pack a “Top Gear Pick” of 2016. Read their recap and their full review, and/or scan other products that made their cut.

If you’re in the market for a new pack, or if you regularly recommend models to others, I genuinely believe that the Flex Capacitor is worth consideration. I would insert it into the same conversation as the Osprey Exos, ULA Catalyst and Circuit, Gossamer Gear Mariposa 60, and Granite Gear Blaze and Crown. These packs weigh 2-3 lbs, are made of durable fabrics, and remain comfortable when loaded with a week of food and a bear canister.

The most significant advantage of the Flex over these other packs is its volume adjustment: with just an extra few ounces of build, it covers the same range as two conventional packs. It’s also only $200, which is very competitive.

I’ve been singing the Flex’s praises for a while, but I would completely understand any skepticism given my involvement with the project. But I’m hoping that Gear Junkie’s endorsement will help convince you. And if you want even more, read Paul Manganti’s first impressions and the user reviews (so far, a perfect 5/5) on the product page on SD’s website.

Ultimately, the “best” pack is the one that wears most comfortably, satisfies most of your needs, and that is within your budget. It may not be the Flex Capacitor, or it may be. Give it a chance.

Posted in on January 3, 2017


  1. Adam Walderman on January 5, 2017 at 2:12 pm

    Just stumbled across this bag today. I am looking for a relatively lightweight bag that can fit a BV500, compress well for different loads, and, of course, feel comfortable. I was strongly considering the SMD Fusion 65. There seems to be very little info out there on the Fusion. Do you have any feedback on the Fusion 65? I like that there is no load restriction and the suspension looks top notch. The Flex Capacitor is lighter and has the zippered top (but lacks any over the top compression/lashing). Also, can a BV500 fit horizontally in the Flex? Thanks for all you do Andrew. Great info.

    • Andrew Skurka on January 5, 2017 at 3:15 pm

      I had the Fusion 65 and Fusion 50 as part of my demo program for my guided trips, but they were not regularly taken out and I can only recall feedback from one client who had any previous experience with packs. He used the 50L, and felt that the volume was mismatched with the suspension, i.e. if he was using a pack that small, he probably would not need a pack with that load support. Let me ping him to see if he has anything else to add.

      For what would you need over-the-top lashing on the Flex? We thought about installing some anchors there, but decided not to: few users would ever need it, and it would block access to the main compartment.

      Yes, a BV500 can fit horizontally into the Flex. Look at the first side-by-side photo on this page, https://andrewskurka.com/2016/sales-pitch-seven-reasons-the-flex-capacitor-40-60-pack-stands-out/. In the right photo, the BV500 is horizontal near the top of the pack, with room to spare.

  2. A Walderman on January 5, 2017 at 8:08 pm

    Is there anyplace in the Los Angeles area to see the pack in person or is it only available online?

    • Andrew Skurka on January 5, 2017 at 8:16 pm

      Not yet. It’s a Spring 2017 product and few stores have any spring inventory right now. If you call SD customer service, they might know dealers in your area that are scheduled to take delivery within the next few months.

  3. Liz on January 8, 2017 at 5:15 pm

    I’m in the market for my first real pack, and I’m intrigued by the simplicity and versatility of this one. How would you attach a therm-a-rest zlite: side pocket and compression straps?

    • Andrew Skurka on January 8, 2017 at 5:32 pm

      I would probably put it on one side. But unless it’s a non-full length pad, it probably will not fit in the side pocket. But it does not need to — the two compression straps will keep it secure.

      You could also attach it to the rear if the gusset is fully expanded. The gusset is about the same width as a Z-Lite. This will block access to the gusset, and thus your ability to adjust the pack’s volume, but that operation tends to be a morning-only affair — set it and forget it, at least until tomorrow morning. A pad will not fit there when the pack is compressed.

      I might also take the opportunity to consider an upgrade to an air pad. Closed cell foam pads are cheap and durable, but air pads are substantially more comfortable, and at least as warm for their weight as CCF pads.

  4. Hiking Nerd on January 12, 2017 at 8:57 pm

    This is a great pack! Since there were no other videos about the Flex Capacitor besides the official product video, I went ahead and did a review here:


    If any of you have questions that you would like an unbiased third party to answer, feel free to leave it at the bottom of the Youtube video.

    • Andrew Skurka on January 13, 2017 at 8:21 pm

      Great video, thanks for putting it together. Shared it on FB earlier today.

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