MXXY Hydration Pack: A Dual-chamber Reservoir Mixes Fluids [Review]

The MXXY Hydration Pack utilizes a unique dual-chamber reservoir for carrying and mixing two different drinks on the trail.
MXXY Hydration Pack

MXXY hydration pack

Hydration is an absolute necessity for spending a full day on the trails. This essential safety measure was recently brought to the spotlight when a mountain biker died from dehydration in the 100°+ temps near Palisade, Colorado. Similarly, I have seen riders bonk, or even worse, collapse, in need of medical attention during extreme endurance activities in the heat.

MXXY hydration pack design

The MXXY hydration pack is the first of its kind to offer a dual-chamber reservoir that holds 1.5L of water paired with .75L of your “booster” nutrition of choice. MXXY promotes it as “The easiest way to integrate personalized hydration into your routine.” Where a traditional hydration pack has the drinking tube running along one of the shoulder straps, the MXXY adds a control dial on the other side allowing the wearer to adjust the ratio of water to supplements.

The round control dial displays either a blue (water) or an orange (booster supplements) color coding to represent water vs. nutrition being dispensed. A magnet and a full-length, rubber-coated zipper keeps the tube and control line secured along the shoulder straps. The control dial allows a 100/0, 75/25, 50/50, 25/75 or 0/100 water-to-booster ratio.

The two separate bladders each feature a sliding closure system, and they snap together to fit into the bag as one unit. Connected to the MXXY tubes, the bladders slide into the pack from the top Velcro enclosure. The control system wire adds another bit of complexity and is stiffer than the water tubes, making setup a bit more cumbersome compared to traditional hydration systems. The two bladders can also be washed in the dishwasher to avoid any unwanted bacteria between uses.


The pack design is simple and elegant compared to other packs on the market. The materials are a quality combination of polyester and nylon. Available in black or space gray, it has a very sleek and streamlined look.

The outer pocket area and zippers are all waterproof, but the top flap, sides and straps are not. There are two main compartments: one is isolated for the hydration/booster, and another is for clothes, gear, and food. The hydration compartment has an upper Velcro flap, instead of a traditional zipper. While the flap provides flexibility for the hose and control line, the design seems like an afterthought since there are larger openings on each side allowing the elements to get inside. The second auxiliary compartment features one additional zipper pouch with a microfiber liner. 

MXXY hydration pack construction and fit

Thrown over the shoulders for the first time, I can describe the feel as non-sporty. It lacks the body-friendly conforming shapes of other hydration packs I have used. Due to the nature of the zipper sleeve system, the straps are rigid with the underside mesh also having a rougher feel. The construction description on the MXXY website mentions a “microfiber neck liner” that my sample did not have. Upon comparison to my other hydration pack, the MXXY straps are less shapely and mounted closer together at the backpack junction. 

On the trail

On Father’s Day I planned on an all-day, 50-mile mountain bike ride which was perfect to test out the MXXY. While packing my supplies, the smaller size and limited space became evident. The two main compartments filled quickly, with no room for additional clothing or semi-bulky items. The main storage compartment became a catch-all for my phone, food, and nutrition while the trail tools went into the small inner zipper pouch. There is a small amount of room on top of the hydration reservoirs, where you could fit a rain jacket or sandwich and cover it with the Velcro top flap.

The MXXY design is not cycling-specific, but when I was in a riding position, the rougher mesh was not welcome on my bare neck. When loaded down with gear the straps stay in a good place, but when the pack lightens up the stiffer straps move around more, causing the neck rub. The contact was only when in a riding position, so this was not an issue when hiking. This would also be something to consider before wearing a tank top with this pack.

The MXXY control dial worked well mixing the liquid in the two reservoirs — blue for water and orange for the supplements — with subtle clicks in between each setting. Unfortunately due to the amount of hose length running from the bag to the bite valve, it took a good few gulps before you notice the change in mixture. This is a characteristic that really can’t be designed around, so it pays to just be proactive about when you will need the supplemental ingredients. When the supplements do eventually run out, the system allows you to keep drinking water only which also has the added bonus of lightly rinsing the tubes before getting around to cleaning it more thoroughly.

The MXXY reservoir — known as MXXY Core — can be purchased by itself for $150 and should fit inside most hydration packs.

Pros and cons of the MXXY Hydration Pack


  • Drink two different drinks with one hose
  • Dishwasher safe


  • Comparatively complicated setup
  • Pack can be uncomfortable on the bike
  • Not much storage inside the pack


This is a great looking product paired with a great concept for big days on the trail. The fit is pretty basic, but not uncomfortable. The basic strap shape lends itself well to a more upright hiking position rather than in an aggressive riding position. There is limited storage on the inside due to the dual reservoir with limited compartments throughout. The hydration ratio mixture works well and the control knob is intuitive and easy to reach. The hydration system is a chore to set up, but makes life easier switching between your drink preference. At the price of $199, it costs more than a similarly sized, single-bladder product, but it might be worth it to eliminate the need for a separate water bottle completely. It is a very effective tool for my shorter 20-40 mile XC races or bigger days of pedaling with friends.