In over a year of extensive field use I’ve found the Crux a reliable top performer, even in difficult conditions.
In over a year of extensive field use I’ve found the Crux a reliable performer, even in difficult conditions. It is the only stove in its class that has a wide burner head. Other canister stoves with a similar size burner head are almost double the weight. The wide, even flame distribution (with no hot spot) and excellent flame control make the Crux a top pick when cooking with large pots or for difficult cooking tasks like simmering food or grilling backcountry pancakes. The Crux has a unique folding ball-joint design and stows to an incredibly compact size – compact enough to nestle into the bottom cavity of an 8-ounce fuel canister. The Crux is the fastest and easiest to set up stove I’ve used. I can completely deploy the stove (less screwing to the canister) in 3 seconds while wearing gloves. At 12,000 BTU/hr the Crux did quite well in our boil time and fuel efficiency tests under optimal (calm) conditions, but was only average in our laboratory wind tests. I’ve found that a well-designed, full circumference windscreen, significantly improves the Crux’s performance in windy field conditions and narrows the performance gap. The Crux is significantly less fuel-efficient than the Jetboil.
• Stove ID
|Brunton Optimus Crux Foldable Canister Stove|
• Accessories Included
|Neoprene case that fits on the bottom of 8 oz fuel canister|
|Expanded, 3.0 in high, pot support diameter 4.4 in (7.6 x 1.2 cm); collapsed, 2.9 x 2.2 x 1.3 in (7.4 x 5.6 x 3.3 cm)|
|Backpacking Light measurement: stove 3.1 oz (87 g), case 0.9 oz (27 g), canister support 0.7 oz (21 g)|
The Brunton Crux is the most compact stove we tested and is the only mini-canister stove with a larger burner; the burner produces a wide/even flame.
Three things set the Brunton Crux apart from other stoves in its class.
First is its large diameter burner head. Other canister stoves with a similar size burner head are almost double the weight. The wide, even flame distribution and excellent flame control make the Crux a top pick for a 3-ounce stove capable of supporting large pots and difficult cooking tasks like simmering food or grilling backcountry pancakes. The Crux is equally adept at basic boiling; posting good boil times at the moderate flame levels typically used in the field.
Second, the Crux stows small, very small. Using its storage case the stove folds nearly flat and nestles into the bottom cavity of an 8-ounce fuel canister. I can put the Crux and a 4-ounce fuel canister into my 0.6-liter Snow Peak Mug. Or I can put the stove, a 4-ounce fuel canister, windscreen, two plastic bowls, and a lighter in my 1.3-liter Evernew Pot and still close the lid!
Third, with its unique folding ball-joint design the Crux is the fastest and easiest to setup stove I’ve used. I can completely deploy the stove (less screwing to the canister) in 3 seconds while wearing gloves.
I like the lack of a piezoelectric ignition. I’d rather save the weight and frustration and use a lighter. I have yet to find a piezoelectric ignition that works reliably in cold weather. The Crux is easy to light with a match or lighter, even with a pot sitting on top.
The valve has a long wire handle that is easy to reach, keeping your hands well away from the stove’s burner. The Crux has great flame control all the way from full-on roaring to delicate simmer. The flame pattern is exceptionally wide for a 3-ounce stove. Even at lower output levels the flame spreads out on wider pots.
The pot supports are adequate and support larger (2-liter) pots and frying pans with reasonable, if not perfect, stability. The serrations on the pot supports provide a bit of grip to sliding pots. As with all canister stoves in its class, stove and pot stability are not design highlights. Most of us have learned with experience to set up the stove and pot combination with care. The hinged ball-joint on the Crux has a slight amount of play that others have cited as “unstable.” I disagree. The play is minor and in no way effects pot stability. I haven’t dumped a pot from this stove in over a year of use.
The compact Crux Stove has a unique folding ball-joint design for quick deployment.
The Crux also comes with a 0.7-ounce folding canister support (see lead photo). It works best on an 8-ounce fuel canister but will work with a 4-ounce canister. I find that I got enough stability from a bare canister bottom and did not use the canister support in the field.
Ease of Use
The Crux is the fastest to set up and the easiest to use of any stove I’ve owned. I can unfold the stove, extend the pot supports, and deploy the valve control wire in 3 seconds, while wearing gloves! All that is left is to screw the stove onto a canister. The valve control wire is long, easy to use with gloves and gives precise flame control. Stowing the stove is just as fast and easy. Other stoves I own, like the Snow Peak GigaPower and Coleman F1 Ultralight, take longer to set up and stow.
The compact Crux nestles into the bottom cavity of an 8-ounce fuel canister with or without the included neoprene storage pouch.
With its wide burner head, wide flame spread and good flame control, the Crux can do every backcountry-cooking chore from melting snow to grilling pancakes. The wide flame doesn’t concentrate heat in one spot like small burner canister stoves. Even at lower output levels the flame spreads out well on larger pots.
A windscreen of my own design (more wind resistant than the one used in the reported stove tests) improved the Crux’s field performance. With this full-circumference windscreen, I had little problem with reduced boil times and fuel efficiency even in strong wind.
In our lab tests of stove boil time and fuel consumption (Table 1), the Crux performed well under optimal conditions (calm), but was only average in our wind tests. With the “windbreak” used in our lab wind tests (a piece of aluminum sheet surrounding the stove on three sides), the Crux suffered from apparent turbulence within the windscreen, which resulted in a significant loss of heating efficiency.
In typical field use (moderate flame and full windscreen) I found the Crux to be a fast boiling and fuel-efficient stove. In these conditions, it is almost as fuel efficient as the top performing Coleman F1 Ultralight. My field results differ from the lab test results, in most part, due to a more efficient windscreen of my own design. This windscreen improves the Crux’s performance in windy conditions. While one of the more fuel-efficient stoves with a tight fitting windscreen, the Crux was not as efficient as the Jetboil. See Homemade Canister Stove Windscreen and FAQs about Canister Stoves and Fuels for tips on construction and safe use of a windscreen with canister stoves.
See Lightweight Canister Stoves Test Report for more detailed results of our heating efficiency tests on this stove, and all the canister stoves in our review suite.
|Test||Optimal Conditions Full Flame 1 quart water||Optimal Conditions Moderate Flame 1 quart water||Optimal Conditions Full Flame 1/2 quart water||Cold Conditions Full Flame 1 quart water||Windy Conditions Full Flame 1 quart water||Wind + Windscreen Full Flame 1 quart water|
|Crux: Boil Time (min:sec)||3:44||4:31||2:20||7:50||123 degrees*||6:40|
|Average Boil Time for all stoves tested (min:sec)||3:33||4:51||2:18||7:35||87 degrees**||5:12|
|Crux: Fuel Consumption (g)||13.9||10.9||7.5||11.5||27.8||18.4|
|Average Fuel Consumption for all stoves tested (g)||16.1||11.7||8.1||11.5||30.0||18.6|
|Crux: Water Boiled per 4 ounce fuel canister (qt)||8.1||10.4||7.5||9.8||–||6.1|
|Average Water Boiled per 4 ounce fuel canister for all stoves tested (qt)||7.3||9.8||7.1||9.4||–||6.2|
Optimal conditions are 70 °F air and water, no wind. Cold conditions were simulated by putting the stoves and canisters in a freezer overnight at 10 °F, then boiling 40 °F water. Windy conditions were simulated with a box fan providing a 12 mph wind; water and air temperatures were 70 °F.
* Degrees Fahrenheit water temperature was raised after 10 minutes; water did not reach a boil.
** Average amount water temperature was raised after 10 minutes. Of the eight stoves tested with 1 quart of water, only one stove reached boiling within 10 minutes.
No maintenance is suggested in the instructions supplied. The Crux has proved durable with no adjustments or service needed. After a year of use, it works as well today as it did out of the box. Some have questioned the durability and stability of the folding ball-joint, but in over a year of heavy field use, I’ve had no problems with it or any pot stability issues.
While a top performer, the Crux is priced higher than many stoves with similar weight and BTU output. On the other hand it is the only large burner stove in its weight class, and it packs to a very small size. It is also the easiest and fastest stove to deploy and use. Using a well-designed windscreen and a moderate flame I found it to be fast boiling and one of the most fuel-efficient stoves I have used.
Tips and Tricks
Like most canister stoves, the Crux is most fuel-efficient at a moderate flame level. Unless you have fuel to spare and need the fastest boil times, use it at medium flame. Even at medium flame, due to its wide burner, you’ll get a good flame spread. Though it weighs almost an ounce, it’s tempting to use the neoprene storage pouch for its space savings and convenience. It also keeps some of the stove’s sharper edges from poking into your delicate ultralight gear. Skip the canister support.
Recommendations For Improvement
The Crux was a standout in every category we evaluated, except for heating efficiency, which is what bumped it to third place in our reviews (behind the Coleman F1 Ultralight and Jetboil). Its burner design appears to be a two-edged sword; on the one hand it provides great flame spread, but on the other hand it makes the stove more susceptible to wind. Thus my recommendation is to find a way to make the Crux more wind resistant, while retaining its superb features and cooking performance.