WE DIG
WE DON’T
ABOUT THE RHYTHMUS RP 9L HYDRATION PACK
Rhythmus was born as a creative outlet for founder Tom, who has been designing bags for the past 7 years as his “9-5”. Tom is currently working with a very high-end brand you might be familiar with, Cotopaxi, and Rhythmus was created as a passion project to expel some creative energy.
At its core, the Rhythmus RP 9L pack offers a total of 9 liters of storage capacity, surprizing with such a small footprint. Additionally, there are exterior straps that allow you to bring along an extra jacket or store knee pads on big climbs. Let’s break this pack down section by section.
H2O | Hydration is in the pack’s name, so there is no surprise that it is compatible with up to a 2L bladder, so long as you don’t go above 14” (355mm) in height. It is important to note that Rhythmus does not include a water bladder. While at first this had me bummed, I get why they are doing this. Like many of you, I have some old bladders hanging out that are in perfectly good condition. I was able to use one from an older hiking backpack. Rhythmus suggests the use of the HydraPak Velocity 1.5L, and this is the bladder I will be upgrading to, eventually.
Editor’s Note: Don’t forget to keep your bladder clean; it does not take long for mold to develop!
MATERIAL | Rhythmus built the RP 9L pack from a typical Nylon, Polyester and Elastane material mix. Nothing crazy fancy or groundbreaking here. Why reinvent the wheel when you can use it to your advantage? While these materials do not offer any crazy groundbreaking innovations, they are tried and tested, get the job done efficiently, and come in at a reasonable price. The pack also features a C0 DWR finish to help repel water, and is completely PFAS free. The result is a pack that feels equally robust in your hands and on the trail. While they are still a small brand, they stand behind their products, offering lifetime repair at a reasonable cost should you run into any issues down the trail.
STORAGE | If you are looking for a way to pack as much as possible in a relatively compact bit of kit, the Rhythmus RP 9L pack is just what you have been waiting for. I have counted a total of 19 compartments and pockets. Seems crazy, right?! On top of the plentiful pockets, you have a set of straps at the base of the pack, which are great for bringing a jacket on alpine adventures or in shoulder season when storms seemingly roll in from nowhere. There are also 5 loops on the outside of the pack to hang various items from, adding further storage options.
Starting with the chest straps, on the rider’s right side there are 3 open stacked pockets. One of these has a hole at the bottom where the straps attach, so nothing small and important goes here. At the base of the chest wing is a zipper pocket, which is great for quick access to a multi-tool. On the back side of each wing, there is an open-mesh pocket, large enough that a standard water bottle can fit. However I don’t advise this, as there is a likelihood of it slipping out due to the shorter overall depth of the pocket.
Moving into the main compartment of the RP 9L, there are 4 separate zones. There is a large dedicated hydration slot with a corded retention strap; 2 medium-sized open mesh pockets, and the large open section of the bag. This open section of the bag can easily fit a sandwich, small camera, or additional layers, and still have room for as many snacks as you can eat when out on an all-day epic.
Onto what I call the “Toolbox”, the compartment on the back of the pack. You can access this through a vertical zipper and a magnetic clasp. Once inside, there are 5 separate mesh pockets. 3 of these pockets are “small to medium” sized – think big enough for a lightweight 29” tube folded up. The final two sections are smaller vertical-orientated compartments, not quite big enough for a protein bar but big enough for tools like a tire lever or plug kit. There is also an open section of this compartment that works well for oddly shaped tool items such as a roll of gorilla tape or small electric air pump.
FIT | One of the big things that separates the Rhythmus pack from the rest of the products in this space is how adjustable the straps are. On both the top and bottom there are adjustable strap buckles. The bottom adjustment mostly controls for torso width, while the upper portion controls for torso height. This independent adjustment allows for both male and female body types to work comfortably with the pack. While the adjustment straps themselves are not stretchy, the material the main strap with pockets has some give to it, helping with fit and comfort. Rhythmus has a fit guide on their website to help new users quickly understand the system. All in all, it is straightforward and allows for nearly unlimited customization.
Across the front of the Rhythmus RP 9L pack are two sternum straps. These are what actually keep the pack on and in place. There are 6 different locations to mount the buckles to, depending on where you want the straps to land. I opted for them to be set on one position down from the top and one up from the bottom. This provided a nice even pressure across my chest, keeping the pack secure.
THE DIRT
SETUP | Getting the Rhythmus pack to feel comfortable was easy. I adjusted the shoulder straps first, then worked on the side straps, and finished with the sternum buckles. I adjusted the fit once I had the pack loaded, and made some adjustments depending on the ride loadout. I wanted it to sit a bit higher which was an easy change, but it would be wise to adjust fit once the pack is loaded in future. Moving the sternum buckles was not as easy as the High Above Supernatural Pack, but it was not an issue, as it was not something I adjusted every ride.
CLIMBING | Going uphill with the RP 9L pack fully loaded, it remained comfortable throughout my rides, with no weird hot spots on my back or shoulders. When I had it packed for an alpine adventure, the weight was noticeable on my back, but that really was ok as I knew I had hopefully everything I would need for any situation on my back, including bear spray. It is easy to overpack with the Rhythmus RP 9L as there is so much room. For snack organization, I used the inside main compartment for duplicates or larger items like apples or a sandwich.
My front pockets were home to bars, gummy bears and gels, the things you would want while still pedaling. I mixed up where these were stored, but for the most part snacks lived on the right side with the upper pocket on the left side being my garbage. The zipper pocket on the right was home to my multi tool, something I use frequently on most bikes, as the seat post height is still a constant battle for me on test bikes. The larger left zipper pocket is where my phone lived on every ride. Both zippers were easy to access with one hand and with a glove on. The water bladder stayed in place thanks to the built in hanger strap, and the hose was easily routed through the top of the pack for one-handed access when your thirst needed quenching on the climbs.
On days when temperatures were above 80, the Rhythmus pack created notable heat, and the subsequent sweat was noticeable. While most packs struggle with this, the RP 9L had a notable lack of ventilation. I was not mad about it, as this pack offered a heck of a lot more storage than others, so it was a sacrifice I was ok with. On the opposite end, when temps started to drop this fall, the pack acted as a bit of a vest holding and retained some heat on cold mornings. While it would be great to see this improved, the addition of new pads, frames and other materials would add to the weight and cost of the pack, which is undesirable. Overall, the heat build-up was acceptable to me, and to be expected with this type of product. So, until I find one that causes zero sweat build up, this will be the norm.
DESCENDING | Going down the with Rhythmus RP 9L was a breeze. I rarely thought about it, only on extreme occasions when it was stuffed to the max with goodies. I swear I am not a pack rat, I just like to take anything my friends might need as well. The pack stayed secure even on rough terrain, which was no surprise as the straps are quite thick and can be cinched fairly tight. Speaking of straps, I never had them loosen up all on their own, which I have run into on packs like the Evoc 3L. When on moderate grade descents, it was easy enough to snag the bladder straw for a quick sip. Something good to know if you are doing a big mile race and do not want to waste any time, although we’d recommend taking extreme care when doing so.
Overall, nothing major stuck out with the Rhythmus RP 9L. The pack did not do anything funny or cause me any issues during the most important part of the ride. With 2L of water, enough snacks for three days, extra layers and tools it’s going to get heavy. But the pack held and managed that weight with ease.
Lastly, I just wanted to touch on the “toolbox”. I was able to keep a spare tube, two plug kits, C02’s, electric mini pump, zip ties, spoke tool, knife, medical tape, gorilla tape, and a few other odds and ends in there with some room to spare. You can easily organize and securely store all the tools you might need, within reason. I really liked this option as I am frequently swapping bikes, so having everything in one place made a big difference to my pre-ride preparations.
HOW DOES IT COMPARE
The best packs I can pit Rhythmus’s pack against are the High Above Super Natural and the EVOC 6L. The High Above is sleek and simple, with much less individual pockets, but still plenty of storage. The EVOC lives right in the middle of the three options. When it comes to main compartments, the High Above takes the win with its slightly deeper profile. When comparing comfort when loaded, the EVOV edges the others out thanks to its elastic straps, but with that said, these do breakdown over time and the pack does not stay as secure. For external storage, the winner is the High Above pack, thanks to its helmet-carrying system in addition to the webbing. While you could fit a helmet on the, RP it is not as seamless.
For value, each pack has its own set of wins, the $240 High Above Supernatural is the most expensive on paper, but it includes a 2L bladder and is Made in the USA, which we love to see. The EVOC comes with a bladder at a $150 RRP, making it the most affordable. When it comes to the price for what you get, the Rhythmus offers tons of storage and organization at a reasonable price if you are ok with a bit more heat build-up than the competitors.
The Wolf’s Last Word
If you are looking for one of the most feature-packed hydration vests to keep you fueled on all-day epics, then the Rhythmus RP 9L leaves little to be desired. While it may be a bit bulky for quick lunch laps and run a little hotter than some, it’s a solid pack offering for the right rider. 
Price: $160
Website: Rhythmus.equipment
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ABOUT THE WOLF
Cole’s den is in Spokane WA, where he relocated a few years back. Growing up in the lush, loamy playgrounds of the PNW, his soul is forever tied to steep, rooty descents and that unmistakable squish of perfect dirt. After 19 years of shredding, Cole’s been on every kind of rig out there. Once a die-hard fan of big travel bikes, he’s now on a quest for the mythical short-travel do-it-all machine. And yes, skids may be for kids, but this middle-aged manchild is here to prove they’re also for anyone who loves having a damn good time.
Rank: Professional Amateur
Size: 6’1” / 185cm | 170lbs / 77kg
Social: @adventuresbycole
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