Optimus
Optimus Crux
- Weight: 8/10 How much it adds to your pack.
- Packed size: 7/10 How much room it takes in your rucksack.
- Boil speed (still air): 9/10 How fast the maker says it boils 1 litre in still air. Wind slows every stove: see Wind performance.
- Wind performance: 3/10 How well it keeps boiling in a breeze, as sold, without an extra windshield.
Solo ultralight walkers and bikepackers who want the smallest cook kit possible
- Fuel
- Gas
- Weight
- 83 g
- Boil 1 L, still air
- 3:00
- Windshield in the box
- No
Packed size 0.147 L, 7.6 x 5.7 x 3.4 cm Compare with a 2-litre bottle
Shorter than a 2-litre bottle and thinner than one. Drawn to scale.
Where to buy
Alpinetrek £42.60 In stock. Delivery £4.49. Page shows £51.95 struck through (its own earlier price, not a list price); free delivery from £85; delivery in 5-7 working days.
View at shop: AlpinetrekUltralight Outdoor Gear £64.99 In stock. Free delivery. List price £71.99.
View at shop: Ultralight Outdoor GearPrices checked 8 Nov 2026 on each shop's own page; shops can change them. We earn no commission on these links; shops are listed by price. More
Our ratings (out of 10)
1 to 10, compared with the whole market. Each says what it's based on. How we score
Weight
From maker's figures 8/10How much it adds to your pack. 8: Clearly better than most.
83 g (Optimus; Live for the Outdoors also gives 83 g) sits in the 60-119 g band.
Packed size
From maker's figures 7/10How much room it takes in your rucksack. 7: Better than most.
Optimus gives 76 x 57 x 34 mm folded: 7.6 x 5.7 x 3.4 = 147 cm3, about 0.15 L, in the 0.08-0.19 L band. It also fits into the hollow in the base of a 230 g canister. Live for the Outdoors and Bikepacking.com list 6 x 4 x 9 cm stowed (about 0.22 L, the band above); we band Optimus's figure. Alpinetrek and Ultralight Outdoor Gear still print an older 84 x 57 x 31 mm.
Boil speed (still air)
From maker's figures 9/10How fast the maker says it boils 1 litre in still air. Wind slows every stove: see Wind performance. 9: Among the best you can buy for this.
Optimus gives an average of 3 minutes (180 s) for 1 litre, under the 190 s line. Live for the Outdoors timed 4 min 50 s for 500 ml at 14 °C in a breeze of about 10 km/h, so expect slower outdoors.
Wind performance
Estimate from maker's specs: windshield in the box 3/10How well it keeps boiling in a breeze, as sold, without an extra windshield. 3: Below average. Fine for some trips, not others.
Estimate from maker's specs
In short
Good for
- Solo ultralight walkers and bikepackers who want the smallest cook kit possible
- Sheltered pitches and valley camps, or anywhere a windshield is carried
- Fastpacking and summit brews where packed size matters more than wind performance
Strengths
- Folds flat to about 0.15 L and slots into the hollow in the base of a 230 g canister
- 83 g with a 3,000 W burner; Optimus quotes 3 minutes for 1 litre
- Wide burner head and pot supports (10 cm across) spread heat evenly and suit a wide range of pots
- Live for the Outdoors found a genuinely low simmer and good build quality; stuff sack in the box
Weaknesses
- Live for the Outdoors rates its wind resistance as fairly poor: 500 ml took 4 min 50 s in a breeze of about 10 km/h, against Optimus's 3 minutes for 1 litre
- Simmering is fiddly: the flame went out unwatched for Bikepacking.com, and it needs frequent adjustment for Live for the Outdoors
- No regulator, so power falls in the cold and as the canister empties; not for winter
- No built-in igniter, so carry a lighter; only three pot supports, so less stable than four-armed stoves
- Wide flame creeps up the sides of pots with a base under 10 cm; the folding joints make it less sturdy with tall pots
Sources
We haven't tested this ourselves. Every score comes from these specs, tests and reviews.