A question from reader, Scott F:
Will a Bearikade Weekender canister fit horizontally in the Sierra Designs Flex Capacitor 40-60 Pack?
To this specific question, my answer is: I don’t know for sure, but it should. I don’t own a Bearikade so I have not tested its compatibility, and I don’t recall any guided clients last year with both a Flex and a Bearikade.
However, I know that the BearVault 500 (which I own and which is similarly sized) will fit horizontally inside the Flex Capacitor when it’s fully expanded. I keep it about 6 inches from the bottom, sitting on top of my sleeping bag and pad, even though this is the narrowest part of the pack (because of the curvature of the Y-shaped stay). If loaded higher in the pack, it fits even better, with no tension on the pack body.
The BV500 slides in and out easily of the Flex — it’s not a fight. And it has no adverse effects on the pack: the side pockets and compression straps remain fully functional, and there is no change in its load-carrying ability or its back panel shape.
The only minor issue is that the canister will place disproportionate tension on the pack body — the main compartment is shaped more like a half-cylinder than a rectangle, and therefore doesn’t have “corners” that match those of the canister. Just be careful of abrading the pack where the top or bottom of the canister is pushing hardest against the fabric.
The Bearikade Weekender is slightly smaller than the BV500, especially in the length:
- Bearikade Weekender: 9-inch diameter x 10-inch length
- BearVault BV500: 8.7-inch diameter x 12.7-inch length
Based on the fit of the BV500, I will speculate on how several other popular canisters will fit inside the Flex Capacitor:
- Ursack S29.3 AllWhite (8″ x 14″): better than the BV500, because it is soft-sided
- Backpackers Cache Garcia (8.8″ x 12″): slightly better than the BV500
- Lighter1 Big Daddy (8.7″ x 13″): similar to the BV500
When considering the suitability of a backpack for trips on which canisters are required, the “Does it fit?” question is an important one. But I think it’s equally necessary to ask, “How well does the pack carry with a canister?” Canisters add weight and bulk, and many otherwise nice packs perform poorly when loaded with this item. More specifically:
- If a pack has too little volume, after inserting the canister there is little room left for anything else;
- If the pack is too narrow, the canister alters the shape of the pack, possibly creating a “bulge” against your pack or putting excessive pressure on delicate stays; or,
- If the pack is not designed to carry heavier loads, it becomes uncomfortable to wear.
In this regard, I think the Flex performs exceptionally well. On multiple trips last year I loaded the Flex with up to 40 lbs, including a full BV500 and sometimes guide gear or an ice axe. To finish the season I carried out 70 pounds of elk meat. While the Flex is 8-16 ounces heavier than the bulk of “ultralight” packs, it carries weight better than perhaps all of them.
Questions about bear canisters or the Flex? Leave a comment.
Disclosure. I strive to offer field-tested information, insights, and advice, and I have a long-term incentive to be a trustworthy source. I do not publish sponsored content or native advertising, and I do not accept payments in exchange for reviews. I have no financial affiliations with or interests in any brands or products.
This website is supported by affiliate marketing, whereby in exchange for referral traffic I receive a small commission from select vendors like REI or Amazon, at no cost to the reader. This post contains affiliate links.
Additional disclosure: I co-developed the Flex Capacitor with Sierra Designs. I have been honest about its shortcomings. Overall, I think it’s an excellent product.