A new lightweight pack is always interesting, especially when it comes from Ron Moak of Six Moon Designs and Brian Frankle, founder of ULA. These two hikers know packs and know about designing lightweight gear. The Fusion 65 is the largest of a range of four packs and designed ‘for long distance backpacks by long distance backpackers’. The designers looked at packs with fresh ideas and came up with a whole new back system intended, they say, ‘specifically to eliminate the need to factor in total pack weight when choosing a pack. These lightweight packs are designed to comfortably carry whatever the pack will hold.’ That’s a bold claim as most lightweight packs do have limits as to the weight they can handle, usually 12-15kg.

The Fusion 65 weighs 1200 grams, which certainly makes it a lightweight pack. There are 27 litres of volume per 500 grams of pack weight. Many self-styled lightweight packs have less than 20 litres per 500 grams, few have more than 27.

The new back system consists of a flexible metal strut embedded in a sheet of padded flexible plastic that forms a shoulder yoke and then narrows to a 110cm strip that runs to the base of the pack. A wide padded hipbelt runs behind the frame. This is made from stiff foam backed by rigid plastic and articulated at each end so it wraps round your hips easily. The central buckle has two adjustment buckles on each side so the angle of the hipbelt can be adjusted for a more precise and comfortable fit. In my experience the hipbelt is usually a weak point on a lightweight pack, often being nothing more than two wings of foam that don’t support weight well, which is fine for light loads but once over 10kg a better belt is needed if, like me, you like to carry most of the weight on your hips. The Fusion 65 hipbelt looks like a hipbelt from a much heavier pack, a real hipbelt designed to support heavy loads in fact.

Whilst there is only one size of pack there are three sizes of hipbelt and shoulder strap so it can customised for a good fit. The shoulder harness is adjustable too, by a ladderlock system reminiscent of that on the original internal frame packs from Lowe Alpine over forty years ago. The harness attaches by a long and wide piece of Velcro. Separating this to adjust the pack is quite difficult even with the shaped piece of plastic provided for the purpose. Once done there’s no need to adjust it again though and the Velcro should never rip out.

There are also adjustable top tension straps so the top of the pack can be pulled in, lifting the shoulder straps off the top of the shoulders, and a sternum strap with a whistle built into one of the buckles.

Overall this back system is far more sophisticated than that found on most lightweight packs, as it needs to be for heavier loads. But surely lightweight packs and heavy loads don’t go together? On long trips and in remote places they can because however light your basic gear food, water and fuel all have to be added. A week’s supplies can easily weigh 7 or 8kg on its own.

As well as having a back system unlike other lightweight packs the Fusion 65 also looks very different. It’s not made from Dyneema so it doesn’t have that familiar white grid pattern. Instead it’s made from a nylon fabric I hadn’t heard of before called Robic, which is said to be tough and durable. Six Moons Designs use two weights of Robic, 420 on the main pack body, which has a diamond grid pattern, and lighter 210 on the side panels, which has a plain weave. Both feel pretty tough. Mipan, the makers of Robic, says it stays new longer than other fabrics. I wish it didn’t! That’s because the Fusion 65 is only available in bright gold (Six Moon Designs call it marigold) and white. I much prefer duller colours and I was hoping that a bit of use would stain and darken the pack. However despite being dumped on muddy ground and laid in peat bogs it has stayed stubbornly bright and clean.

The pack itself has a roll top reminiscent of ULA packs, two small stretch mesh side pockets that will hold water bottles, a big open-topped stretch-sided rear pocket, roomy zipped hipbelt pockets and a zipped inner stash pocket. I’d have liked bigger side pockets but overall it was fine once I adapted my packing to its configuration. The pack is tapered, being wider at the top than the base, which is good for ensuring all the weight isn’t low down, which is bad for comfort and stability, and also makes it easier to find stuff. Six Moon Designs describe the pack as bear canister compatible, not something relevant to British backpacking but important if you’re hiking the John Muir Trail. The wide top does make loading a canister quite easy compared with some packs. (Yes, I have canisters at home, bought years ago for US hikes).

Six Moon Designs give the capacity as 65 litres including the pockets and the extension collar. The main pack holds 51 litres. Each side has two compression straps, the top ones coming round the side of the pack. These don’t run over the pockets and impede access. The rollover top has buckles on each side and there is a strap that runs from the front pocket over the top of the pack to hold everything in place. There are also lower front straps for attaching a foam pad. With all these straps it’s possible to ensure any size of load is held firmly in place. Some of the straps are a little short though. I’d have liked a longer one over the top of the pack as this was at its limit when the pack was full and also longer side ones as I could only just squeeze a very thin short foam pad behind them.

To find out just how good the Fusion 65 is I took it on this year’s TGO Challenge. In 14 days I walked some 200 miles with a load ranging from 15-18kg. My shoulders and hips never felt sore so the pack certainly handled the load well. The frame transferred the weight to my hips and the pack didn’t sag, unlike some lightweight ones. I didn’t have to pack it particularly carefully either as the frame and padding ensures nothing can poke you in the back. Another advantage was a less sweaty back as the area of close contact is smaller than with most packs. The Fusion 65 proved very stable on rough, steep terrain too, feeling as though it was glued to my back. Overall I’m impressed though I suspect that for really heavy loads – 25kg+ – a thicker hipbelt might be needed.

The Fusion 65 held everything I needed for the trip but only just when I had 5 days supplies. For longer trips and winter use I’d love to see a Fusion with a 65 litre main compartment. This may come as Six Moon Designs promises more packs in the future. In the meantime the Fusion 65 is certainly one of the best lightweight packs around for those who sometimes carry more than ultralight loads.