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Over the past few years, top-mounted butane/propane canister stoves have
become exceptionally popular with lightweight backpackers. These stoves
enjoy a long list of advantages over alternative technologies, but still,
are not perfect. One of their principal weaknesses is poor stability when used on uneven surfaces, an issue that
often limits safe placement options in camp. This article examines three approaches to solving
the problem: two commercial and one do-it-yourself. I should also mention
that much of what is discussed here applies equally to top-mounted canister
lanterns.
Note that many of the photos contained within this article are linked to larger versions that can be accessed by clicking on the red "(+)" in the caption area (or on the photos themselves). Canister Types Most
backpacking stoves currently designed for butane/propane (and/or iso-butane) fuel
mixtures
use one of four canister types:
A Revelation Although I previously knew that canister valves are standardized (to the extent noted above), I didn't realize until I began testing stands that their base dimensions are not. It turns out that the diameters of many similarly-sized canisters are slightly different from one another, a fact that creates problems for the snap-on stands discussed below.
I discovered that among the popular canisters brands included in my test sample, manufacturers currently use six different base dimensions (listed from largest to smallest).
Commercial Stand Options At least three companies (there could be more) currently offer collapsible plastic stands that can be snapped onto the bottom of stove canisters to improve stability. These companies, along with manufacturers' photos, are noted below. In addition, Jetboil has announced a new conversion kit for their existing stove system that allows their customers to use their own cookware. It includes a pot support and canister stabilizer legs and is scheduled to be available May 1st.
For my tests, I purchased two of the three currently available models: the Primus Foot Rest™ (from REI) and the Brunton CanStand™ (from Hudson Trail Outfitters). Markill products are manufactured by Vaude, a German company that distributes primarily in Europe. All are available online, but Markill products are more of a challenge to find. Because the Markill features appear to be very similar to the other two, I decided that the Primus and Brunton were probably fair representatives of this design approach. Design Notes Both of the tested commercial products work the same way. They collapse for storage by rotating the legs around a center spindle, then open by reversing the process. When opened, they are designed to snap onto the bottom lip of a fuel canister, increasing stability both by reducing the number of contact points with the ground and by expanding the stove's footprint. Both stands have two or three sets of "gripper hooks" that allow them to engage with different sized canisters. These grippers are not adjustable, however, so the canister sizes they can accommodate is fixed. I discovered in testing that neither of the two stands tested fits all (or even most) brands of canisters well. By "well", I mean a good, secure fit that assures that the stand will stay attached to the canister. To be fair, I suppose that even a "sloppy" fit could be of some value on uneven ground, but only a snug fit will keep a stove loaded with a pot full of water from tipping over. Another fit problem shared by both models occurs if the legs are not fully rotated into open the position. This can happen fairly easily, especially if the stove/stand is moved. What happens is that the distance between grip points decreases when a leg is out of position, loosening the fit. The stand will then often fall off the canister. Designed as tripods, both tested models succeeded (mostly) in reducing the number of contact points with the ground, which, in my opinion, accounts for most of the stability improvement. I make that statement based upon my experience with the do-it-yourself option described below. In contrast, widening a stove's stance seems to have less effect on stability and helps most on fairly level ground (where you probably don't need the help in the first place). In fact, I found that increasing the footprint can actually make it harder to get the stove stable and level under some conditions. When attempting to place a stove on a rock, for example (often desirable in order to get the stove to a more convenient working height), a stove with three legs positioned fairly close together was usually easier to place than one with three legs spread far apart. Primus Foot Rest The Primus Foot Rest is made of molded plastic, has a "wingspan" of about 9 inches when extended, and weighs 0.8 oz, per the manufacturer (my scale confirms this weight). At the end of each leg is a foot that's simply a molded extension of the leg itself (i.e., the feet contain no bottom-mounted traction pads). The legs arch to a height of about 5/8" over the surface beneath (measured at the center). The stand also contains three sets of gripper hooks for attachment to multiple sized canisters.
Canister Fit The Foot Rest is optimized, as you might guess, for Primus canisters and accommodates both the "round-top" and "square-top" models (8/16oz) using different sets of gripper hooks for the two canister widths. On their website, Primus states that it "...also fits other brand canisters". Backcountrygear.com says that "...It fits Primus, Camping Gaz, MSR and Coleman cartridges as well..." As it turns out, that's not quite true. The newer Primus "round-top" steel canisters (8/16oz) have base diameters of approx 111.5mm (Group 1), which is the same size as the Camping Gaz valve-type canisters (CV270). Both fit this stand well. However, the MSR, Brunton, Coleman, Snow Peak and similar 4/8/16 oz canisters that have base diameters of 109.5mm (Group 2) don't fit at all (they're too small). When legs #1 and #2 are seated properly, there's a gap of about 2mm at leg #3 (see photo below), which is enough that the stand can't snap into place.
Older
"square-top" steel and aluminum Primus canisters (Group
4) also fit well into a second set grippers. However, the smaller 4 oz Snow Peak / Jet Boil
(90mm) and Gaz CV206 (89.5mm) canisters don't fit into any of the grippers.
*Again, my definition of "fit" is that the stand clips securely to the canister and doesn't fall off if the canister is moved.
REVIEW SUMMARY What I liked: Secure fit on Primus and Camping Gaz CV270 canisters, arch design allows it to span some obstacles and minimize contact with the ground, lightweight. What I disliked: No rubber foot pads to improve traction on rocky surfaces, doesn't fit the popular Group 2 canisters, and the wide footprint actually makes it more difficult to safely place on some surfaces. Overall Grade: C Comments: If this type of snap-on design were the only option available, I might have scored this product a little higher. But because there's a fairly obvious alternative that works much better (see below), I believe it's a sub-optimal solution to the stability problem. One the plus side, at least the traction problem is easy to fix by gluing small rubber pads to undersides of the feet. The Primus Foot Rest is currently bundled with some of Primus' canister stoves and can also be purchased separately from REI for $8.95.
Brunton CanStand The Brunton CanStand is also made of molded plastic, but at 7½ inches, has about a 1½ inch smaller footprint than does the Primus. Per Brunton, it weighs 0.7 oz, (my own scale confirms this weight). At the end of each leg, there's a foot containing a bottom-mounted rubber pad intended to improve traction on slippery surfaces. Unlike the Primus, the Brunton legs don't arch, but instead, lie close (about 3mm) to the surface beneath. The stand also contains two sets of grippers for attachment to multiple sized canisters.
Canister Fit The CanStand fits a wider range of canisters than does the Foot Rest (sort of). It accommodates the Group 1 Primus and Camping Gaz canisters with a good snug fit. The outer set of prongs will also grab the slightly smaller Group 2 (MSR, et al) canisters, but the fit is not as secure. When legs #1 and #2 are seated properly, there's a gap of about 1.5mm at leg #3 (see photo below). That gap is small enough (barely) to keep the stand attached as long as the legs are fully extended; however, if they rotate slightly out of position, the CanStand will usually fall off if the canister is moved. And, unfortunately, because there's no friction force to keep the grippers in place with the Group 2 canisters, the legs rotate with relative ease. I find this interesting, since Brunton's own fuel canisters fall into Group 2 (they've effectively created a design that works better with competitors' products than their own). The remainder of the canisters sizes (Groups 3-6) don't work with the Brunton. The early "blue-top" models of the Glow Master fit loosely, but the current all-black version is about 1mm smaller in diameter and slips out of the stand.
*See my definition of "fit" above.
REVIEW SUMMARY What I liked: Secure fit on Primus "round-top" and Camping Gaz CV270 canisters, also fits smaller Group 2 canisters (though loosely), rubber foot pads to improve traction on rocky surfaces, lower center of gravity than the Primus, lightweight. What I disliked: Legs rotate out of position too easily with Group 2 canisters (usually causing the stand to fall off), and the wide footprint makes it more difficult to safely place on some surfaces. Also, the lack of leg arch means that any obstacle over 3mm high will create a contact point and de-stabilize the stand (the Primus' arch overcomes much of this problem). And one further nit: I dislike gear that's over-emblazoned with manufacturer logos. The CanStand falls into this category, as does some of Brunton's other gear. Overall Grade: C Comments: As with the Primus, I feel this stand is a sub-optimal solution to the stability problem. The Brunton CanStand can be purchased at a variety of retail outlets and can also be ordered online from Brunton's website for $10.00. Super Legs The third approach to the canister stability problem is a do-it-yourself option that I call "Super Legs". The actual build instructions are contained in a separate document, so I'll just discuss the design here. It may seem odd that I'm reviewing my own creation, but since I'm usually tougher on my own ideas than I am on those of others, you'll probably get the straight skinny. If you think I've gone too easy on myself, please tell me so in the feedback forum. Super Legs are simply small stabilizers that can be semi-permanently attached to any size fuel canister (Groups 1-6). The ones I've had the best luck with are made from ordinary wooden spring-type clothes pins. Construction involves separating the two halves of a pair these pins, then working on them a bit with a file and a wood rasp so that they can lock into the bottom lip of a canister. The final build step is to "rubberize" the bottoms of the legs in order to maximize traction. This last process is not mandatory, but really helps on slippery surfaces, like rocks. Once constructed, Super Legs can be mounted to a canister using the means of your choice. They can be attached using electrical or duct tape, nylon straps with side-release or ladder buckles, cable ties, velcro sport wraps, wire, parachute cord, or even a hose clamp. Most people will elect to leave them mounted for the duration of a trip, removing them only when a canister is empty. And because the legs extend less than an inch below the bottom rim, canisters are still easy to pack with the legs in place. Super Legs create stability solely through the "tripod effect", reducing a canister's contact with the surface beneath to three points. Unlike the commercial options, they don't widen a canister's stance, but as noted above, this actually turns out to be an advantage. Constructed as described and attached by most means, a set of Super Legs will add less than 0.5 oz to the weight of your canister (the hose clamp option adds a little more). Super Legs also take advantage of the concave curvature of the bottoms of butane/propane fuel canisters allowing them to "arch over" many obstacles that would have otherwise restricted placement. In contrast, the commercial options work against this built-in curvature, since when clipped into place, they effectively block access to that portion of the canister's anatomy. Though the Primus stand creates some of its own arch, it's only about 0.6 inch at the center. Super Legs, with an approx 1.8 inch rise at the center, create about three times as much arch. Once your stove has been "Legged", you'll probably find that you can place and level your stove in places you wouldn't have considered before. I now routinely use my Primus Alpine stove on rocks, logs, gravel and other surfaces that I would have otherwise bypassed, making it easier to get the stove off the ground and up to a more convenient height. Even on soft ground, the legs help, since I can gently press one or more of them into the ground in order to level and anchor the stove. If you really want to nail your canister down, another option is to slip three hook-style tent stakes under the wrap, one next to each of the legs, then push them into the ground (the stake shown below is a ¼ ounce titanium model). You'll find that the stove is now very difficult to knock over.
REVIEW SUMMARY What I liked: Super Legs become an integral part of fuel canister until they're deliberately detached (no separate parts to keep track of), fit any size canister, won't fall off (as long as they're attached well), allow stoves to be placed almost anywhere, even lighter than commercial options, low cost. What I disliked: I'm still trying to find something. Overall Grade: You get to decide. Comments: If you use a top-mounted canister stove or lantern, I'd suggest skipping the commercial options and building yourself a set of Super Legs. Please let me know what you think by leaving your comments on the feedback forum. There's no need to even register, even though there are advantages to doing so.
Copyright © 2005 James E. Wood. All Rights Reserved. |
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