In a line adaptable, adjustable and comfortable pack heavy-hauling harness designed for packrafters.
Weight (verified): 1525g in Large (shoulder straps 212g; hip belt 376g; back panel 937g).
Where used Four-day packrafting recce on Knoydart, covering about 50 miles.
The Flex PR was supplied free for testing and review by Six Moons and Anfibio
Carries heavy loads as well as a proper rucksack
Includes no less than 9 handy pockets
Four way adjustable hip belt
Fits inside a roomy Anfibio TubeBag (in-hull storage)
As expensive as some top-of-the-range ultralight backpacks
Loads of black buckles with long black straps on the black back panel
Fixed shoulder-strap pockets too small and too high
The slim, central lumbar pad can make make the load roll a bit
What They Say
The [new for 2021] Flex PR is a multi-use pack specifically designed for pack rafters. The Flex PR is a 50L dry bag with a removable suspension system designed for carry heavy loads in comfort. Whether you are portaging on a canoe trip, hunting in the backcountry, or doing trail maintenance, the Flex PR will keep your gear dry, your accessories handy, and your back comfortable.
I’ve long been a fan of pack harnesses as I call them; aka: portage packs or multi-use packs. Once combined with a bombproof drybag like my ten-year-old Watershed UDB, your packrafting load-carrying needs on land and water are solved with an all-up weight of around 2.5kg. Lash all you needs to the harness and hit the hills.
It took me years of experimenting with ex-military and hunting-focussed metal-framed versions before I discovered backpacking-oriented harnesses like my NRS Paragon. No longer made, the Paragon was an inexpensive, basic harness and a bit on the small side for me. The fully adjustable Six Moon Flex PR is up there with a the best hiking load-carriers.
What’s wrong with a regular huge rucksack you ask? Well, they’re not waterproof like a dry bag can be and if you have a dry bag you’ve less need for a backpack. Plus once you account of 4-5kg of raft and accosiated clobber, it won’t all fit in a normal rucksack; on the water you may end up with a soaking backpack. I tried this on my first packrafting overnighter from Morar to Fort William back in 2010 with my Alpacka Llama, carrying a huge roll-top vinyl drybag (left). It sort of worked, but once you get into it, a drybag with the boat inside or out, all lashed to a pack harness works best. Wet things are separated or more accessible.
I jumped in the deep end with my Flex PR, carrying an initial load of 18kg on a four-day tour of the Knoydart peninsula with my Rebel 2K. It turned out to be more walking than paddling, but was a good recce for next time. The Flex PR got a good work out.
Out of the box the Flex PR comes in three sections: the load-carrying back panel incorporating the fabric strap-down section which wraps up around your dry bag and then cinches down. The panel is supported by a removable, pre-bent ribbed alloy stiffening rod which you want to take care not to bend or break. The wide hip belt slips in through a sleeve in the back panel and velcros in place; and the shoulder harness slips down into another velcro sleeve with various adjustment marks. At 6′ 1″ (1.85m) I settled on max.
I do wonder how securely velcro will hold the weight after a while, but it’s not like you’re undoing it several times a day, and most of the weight rests on the hip belt which velcros from both surfaces.
The PR has loads of straps: 6 on the hip belt; 12 plus a bungie on the back panel and 3 on the shoulder harness. You may need a while with your chosen dry bag to configure the PR to your liking. You may also be tempted to snip off the excess on the straps, but initially it’s better to knot them up or try and tuck them in until you know for sure which ones really are way too long. Better too long than too short. The foot-long shoulder-top tensioning straps are primary candidates for the snip, and after a day or two I detached the removable bottom stabiliser straps for securing portage barrels in an effort to reduce strap overload. They had some interesting removable buckles (right) I’ve not seen before.
The Flex PR is designed to be used with 6M’s 50-litre, 227g (8oz) roll-top dry bag (another $45; left) which includes four loops which match up with the harness’s side straps.
No skimpy roll-top bag will do a great job keeping out prolonged rain, persistent waves or enduring rough handling, but I get the feeling packraft adventurers are erring towards stowing baggage inside the hull so a super waterproof dry bag is less critical.
I’d also feel that 50-litres is a minimum for a few days out in the back country. I’d sooner depend on something more robust, though my 1100-g/96-litre UDB is probably overkill. Something like Sea to Summit‘s ovalised Big River TPU roll-top (right) fits the bill and also has side loops to keep it in the harness. It goes for 40 quid in the UK.
It took me a few days to realise my large, sausage-like UDB duffle was not suited to the Flex. A top-loading dry bag mounts better. Every morning I had the chore of re-lashing my black UDB into the harness correctly, made harder by everything being black.
Bothered by swarms of midges or rain, you don’t want to have to think about re-lashing the pack correctly each time and there were times the long, thin load felt lopsided.
Next time I’ll try something else, dry bag wise – and it won’t be black. I also realise the Rebel 2K’s massive in-hull storage capacity now makes a bombproof, over-the-bow dry bag like my trusty UDB a little redundant.
I did try and to dummy rig two old dry dry bags (20 and 40L; left) but I can see it being the same old faff lashing on each time, just with more colour. However, one benefit of this twin-bag system would be they pop right into the 2K’s capacious TubeBags with no repacking required. That would be handy on a trip where you’re switching between walking and rafting more than once a day.
One of the best things about the PR are the numerous pockets which do their best to replicate a regular backpack, adding to convenience on the trail. I missed this on the Paragon. There’s a small hidden zipped pocket inside the backplate, two big fist-sized zip-ups on the hip belt, two detachable side pockets which clip either in series via the side straps, or can be Molle’d on from behind. With a stretchy outer fabric, these will easily each take a 1.5 litre water bottle or a rolled up cag. Next, you have stretchy cinch-up pockets sewn to the shoulder straps but, as others have noted, they’re too small for anything useful (GPS; phone) and set too high. On me they were level with the tops of my shoulders. Although they have to dodge the chest strap, that can be Molle’d up or down in 4 or 5 positions. It would be better if the pockets were Molle-backed too. As it is, it’s easy to buy such accessory pockets.
Not done get. The wide back panel has a big sleeve which swallows a four-part paddle, and in front is a long stretchy zip pocket for more of whatever you’ve got.
My walk was quite hard: 18 miles on day one, followed by a tough, 1500-foot crossing up from sea level and back down to sea level. While I got a few initial aches from old injuries carrying over 18kg, at no time did my shoulders get sore which proves the rigid harness panel was taking the weight at the hip belt. And the hip help is particularly good: the pockets are a useful size and the twin straps each side mean you can cinch it up snugly. I’d have preferred a bigger hip belt buckle and found all the Flex’s clip buckles oddly hard to link without looking; they didn’t readily clip together compared to others I’ve used, possibly due to being relatively bendy plastic.
On the way back to Inverie I decided to strap the packraft underneath the pack using the straps for this purpose. Surprise, surprise the lowered load carried much better, but next time I’ll use a more rugged dry bag. Hung outside and quite wide, the rolled-up boat is vulnerable to getting snagged on barbed wire, farm gate latches, or when being hauled about in transit.
I’ll be doing a packrafting trip in the same area in a couple of weeks and will try a few refinements on the Flex PR.