Nathan Crossover 15L Pack – Great, Light Multi Purpose Pack

Drew Thayer

The Nathan Crossover 15L Pack is a light, low-capacity hiking pack that’s great for run/hike/scramble ventures, bikepacking, and other hybrid activities.

Nathan Crossover 15L Pack
The Nathan Crossover 15L pack loaded for a scramble mission in the Flatirons. This pack carries a limited amount of gear — like climbing shoes, chalk bag, and a windbreaker — really well while running, making it a good choice for hybrid activities.


Nathan, maker of running vests and hand-held bottles, now sells a series of Crossover packs in 5, 10, and 15 liter volumes. I evaluated the largest, 15 liter model for running, hiking, and other outdoor pursuits. 

Nathan Crossover 15L Pack Review

Crossing over: not a running vest, but close enough with a lot more capacity

First things first: these are backpacks, not running vests. Even the 5 liter model carries like a small backpack, with the majority of storage on the back, including hydration (a bladder and hose), and two small pockets on the chest. This will never be the best option for pure running for me, even a long trail run – a running vest, with hydration, food, and gloves on the chest, just carries so much better while running. I could see the 5 liter model being useful on long backcountry runs with cold and/or rain complications where one might want to carry more clothing, but there are some large running vests available these days with back storage that cover that territory pretty well. 


What these packs are great for are those hybrid activities: the big mountain loop with running and hiking. The technical ridge scramble with a trail-run approach. The whimsical run-to-swim venture. For any of these activities when you might do some running, but need to carry a bit more (change of clothes? swimming trunks? climbing shoes? lunch?) these crossover packs do a good job of remaining running-friendly while carrying more capacity. They are built with a tapered construction that tends to keep the bulk of the load centered near the spine, thus avoiding the worst kind of sway that results when heavy objects pile up in the low corners of a backpack. They carry tight to the back, and are easily adjustable to fit tightly over whatever layers you’re wearing with slide buckles on the shoulder straps and twin chest straps. These aren’t sway-free running vests, but they come pretty darn close for backpacks. 

Nathan Crossover 15L Pack
The Nathan Crossover 15L pack as part of my bike-packing rig for riding a 60-mile route of Georgia Pass and Boreas Pass in Colorado. I really liked how it carried on a mountain bike.

Utility and organization

The three Crossover packs do a good job of staying simple, with just enough pockets and design features to make them useful without adding weight or being gimmicky, for the most part. These packs share a common design: a slim backpack with a hydration sleeve and spongy shoulder straps sporting an accessory pocket on either side of the chest and two stretchy mesh pockets on the lower sides of the packs. The chest pockets are not the deep, open-top pockets commonly found in running vests, but rather slim, zipper-closure pockets that fit things like gu packets, energy bars, and sunglasses (as long as they fold fairly flat). They do not hold hydration pouches or cell phones. 


The side pockets sort of work as on-the-go pockets, but not quite, because they are hard to open and hard to reach. However, they are low profile and carry small dense items like energy bars and smart phones really well, without additional bounce. Personally, my shoulder is just barely flexible enough to reach these pockets, and the velcro closure is so strong that they are pretty hard to open one-handed. That said, they work just fine to carry things and I can casually un-sling the pack from one shoulder and access them when I stop moving.


10L and 15L versions of this pack include a simple slide-buckle webbing waist strap that is easily removable. I don’t use it for hiking, but I think it’s nice for keeping the weight stable while running or especially mountain biking (more on that below).

Nathan Crossover 15L Pack - Great, Light Multi Purpose Pack 4

The 15 liter pack has an additional zippered pocket on the back that’s useful for organizing organize small items; it has a small, open-ended internal pocket than can keep easy-to-lose things like chapstick stored in one spot. It also has an additional mesh pocket on the bottom, which lets you add capacity if you need to carry another light layer like a windbreaker and the pack is full.


10L and 15L versions of the pack come with an elastic strap in an “x” on the rear. I personally don’t find these very useful, as they are not necessarily trustworthy. I tend to remove them from packs, or modify them for very specific scenarios (i.e. carrying part of a z-rest pad while bike packing), but they are there. This is the only feature I would consider gimmicky on this pack.


Hydration bladder


I have to admit, the Hydrapak bladder included in the 15L crossover pack has won me over. I used to be a hydration bladder guy, but after years of various models failing in one way or another I haven’t used them for awhile. The culprit was usually a puncture, or the main closure was clumsy and prone to failure (i.e. a tendency to cross-thread, threads leaking, etc). 


These Hydrapak bladders are made of a very soft and flexible transparent plastic that I anticipate will be less prone to abrasion failures (i.e, MSR Dromlite) and avoid repeated stress-point failures (i.e. Platypus). At 3 months of testing I can’t comment on durability beyond these impressions, but the material seems solid. 

Nathan Crossover 15L Pack - Great, Light Multi Purpose Pack 5


These bladders are really easy to fill! Closed at the top with a ziploc-style closure folded over through a beefy plastic clip, I love that I get the entire open top to use when trying to coax droplets out of a tiny spring along a mountain trail. With some of the older screw-top bladders, this was always a problem. If there is liquid water running on a surface, you can get it into the bladder.


The only part of this bladder (really, the pack) that leaves something to be desired is that the magnet that snaps the hose into place on the shoulder strap is kindof weak. This is especially important while running or biking, when you want to be able to take a quick sip mid-trail and stash the hose again in a fluid motion. You have to be pretty accurate with placing the hose to get it to stick, which is annoying. 


Top impressions: a great pack for run/hike, scrambling, and bikepacking


As discussed above, none of these packs would be a top choice for a trail run, for me. Vests out-perform packs for running. However, if I ever need to carry more stuff on an outing that also includes some running, these packs are great. 


My favorite excursions so far with the 15L Crossover pack have been running to ridge scrambles, long runs in the Gore Range high country where I hiked the high passes, and scrambling around the Flatirons above Boulder, CO where I ran the trails to and fro, carrying climbing shoes and chalk in the pack. 


As something of an aficionado of wilderness bike-packing, I want to point out that the 15L Crossover pack is really nice for this niche sport. I tested this pack on a high-country loop from Kenosha Pass to Como, Colorado this summer during the height of monsoon season. As long as you don’t load it too much, it carries weight really nicely on a mountain bike and keeps hydration handy. The slim design of the pack keeps weight held close to the back, especially low on the back where it doesn’t tend to sway. The big, open-mouth hydration bladder is particularly nice for harvesting water from the tiny seeps and trickles that one often finds while riding in the high country. I tended to ride with my phone in the mesh side pocket except for when it was raining hard, and while it was pretty hard to pull it out while riding, it was trivial to swing the pack off one shoulder at a junction and check the map. This pack also did a good job of keeping my gear dry while riding through some heavy showers. All and all, I’m excited to use this pack for future bikepacking ventures. 


FWIW the 15L pack fits a 13” laptop in a case and fits nicely under an airplane seat, so I’ve been using it for travel too. Versatile pack!

Nathan Crossover 15L Pack - Great, Light Multi Purpose Pack 6
Rowan wearing the Nathan Crossover 15L pack on his gravel bike, along with a few frame bags. This pack carries tight to the back and doesn’t sway with pedaling.

One response to “Nathan Crossover 15L Pack – Great, Light Multi Purpose Pack”

  1. […] Competitor packs sport various combinations of waist belts, drink tube retention straps, compression straps, handle loops, external stretch pockets, zipper pulls, etc. These features aren’t necessarily bad – The Nathan Crossover 15 pack, with intuitive organization and a hydration bladder, works really well for bikepacking, as I’ve described IN THIS REVIEW […]

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