The Gravity VF is being discontinued by Primus. I…
Price Paid: $40
The Gravity VF is being discontinued by Primus. I bought it at a closeout price well aware of its limitations from the few reviews I could find.
In concept it should be a great stove but it simply does not perform as designed. I tested the VF on a recent three night 20 mile trip this past Dec. I also own a 15 year old MSR Whisperlite that I think is worn out but MSR wants as much for the repair kits as a new stove. It makes much more sense to just buy a new stove when they go on sale. I will replace the Whisperlite when I can get a deal.
In the meantime, I thought I'd try the VF because I liked the low height and four leg foldup design. On this point it has the Whisperlight beat. If you use ultra light cookware you end up doing a balancing act with the Whisperlite. I also wanted to give the Swedes another try since my old reliable Svea123 days. But as with the once reliable, venerable Volvo 240 the Swedes just couldn't continue the legacy.
OK, now to the stove performance.
I use alcohol to prime my stoves to eliminate soot. I carry it in a small Nalgene squirt bottle, you only need a few ounces for a multi day trip. The stove primes easily. When you turn on the flame it turns blue fairly quickly indicating proper air/fuel mixture. However, the flame emits unevenly around the burner with about half the burner actually emitting flame. The valve is responsive but as with the Whisperlite don't expect simmering. It boils water rather quickly which is all a liquid fuel stove needs to do.
The VF provides an excellent stable platform for pots and pans. The lower burner plate is rather wide and easily catches boil-over that gets burned on. The Whisperlite has the advantage here as the burner plate is small and is often so hot any boil-over gets burned off immediately.
The parts of the VF, especially the pump, are a work of art. Mostly metal with precision fit and finish. The fuel line to pump connection is an elegant press and spring lock. The fuel line is smaller and more flexible than MSR. Unlike MSR, you can get the various individual parts, such as the jet without buying half a stove.
I also like the 0.6L Primus fuel bottle which I'd use with a Whisperlite. It's a 'tween' size of the MSR bottles. Primus' method of shutting down the stove does not always work, supposedly you flip the fuel bottle over and air will enter the fuel line to extinguish the stove. I just turn off the valve; you'll have a few drops of fuel in the line that you can shake out.
The stove folds fairly flat compared to a Whisperlite. It's also about the same weight, ~11oz.
Well, that's it. It's too bad Primus missed the boat on this one; the intentions were good. I think this stove is made well enough and is reliable enough to provide the basic backpacking cooking function (boiling).