Yakima CBX Roof Box Review | A different kind of premium cargo box

It probably won’t come as surprising news that more people have been using their cars to go on vacation instead of risking several hours breathing inside airplanes and airports. With longer trips comes more luggage, and if kids are in the equation, then chances are that SUV you bought for its space and versatility suddenly […]

It probably won’t come as surprising news that more people have been using their cars to go on vacation instead of risking several hours breathing inside airplanes and airports. With longer trips comes more luggage, and if kids are in the equation, then chances are that SUV you bought for its space and versatility suddenly isn’t as spacious and versatile as you assumed. Enter the roof carrier. When mounted to a factory or aftermarket roof rack, a carrier effectively adds the volume equivalent of a midsize sedan’s trunk to the roof of your car or SUV.

Roof carriers are obviously not new, but long before COVID, the outdoor adventure trend was increasing their popularity to the point that brands were diversifying their offerings to include “premium” choices. Besides possessing more advanced features and pricier materials, their sleeker appearance was a better match for the Volvos, Audis and other luxury models that owners were increasingly mounting them too (especially skiers).

The newest such “premium” roof carrier is the Yakima CBX, but it’s doing things a little different. From an aesthetic standpoint, it moves away from the glossy black finish found on Yakima’s existing premium choice, the Grand Tour, as well as Thule’s popular Motion XT.

It instead has a sort of “micro-golfball” surface that creates a more matte finish and could potentially benefit fuel economy (as “Mythbusters” proved when it covered an entire car in golf ball dimples). This surface, in addition to the more angular design, makes it a better aesthetic match for more rugged vehicles like a Toyota 4Runner, Land Rover Defender or the Subaru Outback and Crosstrek I tested the CBX on.

Some of its features transfer from the Grand Tour, most notably Yakima’s unique system for tightening the carrier’s grab hooks to the roof rack. Rather than having tightening knobs or mechanisms at all four attachment points (as the Yakima SkyBox and all Thule boxes do), the CBX has one large knob that you move between each attachment point. It plugs into either side of the carrier when not in use. This allows for a flatter load floor and a larger knob that’s easier to turn (once you’ve torqued it three clicks, you know it’s secure).

The CBX is available in two sizes: 16 and 18 cubic feet. Both are common sizes for the industry, but as I’ve discovered in numerous luggage tests of cars, a cargo volume number doesn’t always equate perfectly to how much stuff you can fit inside. It’s the individual dimensions that can make a difference, and in the case of the CBX 16 I tested, those dimensions differ considerably from others in the industry, including those made by Yakima. 

It is 83 inches long, 38 inches wide and 14 inches tall. That’s longer and wider than the Yakima Grand Tour 16 and the Thule Motion XT L. It’s a few inches shorter in maximum height, hence the common cubic-foot measurement, but it has more of a uniform height versus the others’ ramp-like shape. In this way, it’s more like Thule’s high-end Vector M series –but the Thule’s narrower width results in only 13 cubic feet of space. Being narrower could make it easier to mount something else to a full-width rack (like the Yakima Timberline used on the Crosstrek), which applies to all of the above in comparison to the CBX.

Though I didn’t test any of those other carriers to compare, I can at least show how much can fit inside the CBX as well as how much space it frees inside a variety of test cars.

I started with the same standard set of bags used when testing the cargo volumes of cars: two midsize roller suitcases that would need to be checked in at the airport, two roll-aboard suitcases that just barely fit in the overhead, one smaller roll-aboard that fits easily, and my wife’s blue overnight bag. To these I added our Thule Spring fold-up stroller and a Graco Pack ‘N Play to better approximate a family road trip.

The CBX was able to fit the two biggest bags in its middle section. They were too tall for the carrier’s tapered ends, but one of the larger carry-ons and the smaller carry-on could fit on either side of them. There was some space remaining in the nose. I can’t know for sure, but I have my doubts that the same four bags would fit together in some of the other carriers with pointier noses and shorter lengths. The stroller also fit width-wise and could’ve supplanted one of those bigger bags.

To illustrate how much space the CBX frees up by swallowing those four bags, I placed the same “left-over” items in a variety of different cars. In one case, my own 2013 Audi Allroad, the CBX allowed me to simply carry the standard set of bags without removing the cargo cover, never mind the bonus stroller and playpen.

As for installation, the hardest part is physically lifting a 57-pound, 7-foot plastic coffin onto the roof of a car. I got it off by myself once, but it wasn’t graceful. Thank goodness for my neighbor Grant, but even then, it was still awkward for a pair of 6-plus-footers. I should also note that due to a quirk in test car scheduling, we only mounted the CBX to a Crosstrek, Outback and my Allroad – all low-roofed wagon-like vehicles. The new Nissan Rogue was a no-go, but a similarly tall crossover would have been more difficult and a legitimately tall SUV like a Ford Expedition would’ve required step stools, a ladder or ringing up Jusuf Nurkic.  

Then there’s the main bugaboo about roof carriers: wind noise and fuel economy. For noise, I discovered that it depends on the car. If you have a panoramic sunroof, as in my Allroad, be prepared for your car to be a lot louder – highway journeys perpetually sound like it’s a blustery day. By contrast, the Outback and Crosstrek had traditional sunroofs with solid sunshades – while wind noise did increase with the CBX affixed, it was far less noticeable (only 2 decibels in the Outback).

When empty, a roof carrier also tends to flutter and flex to the point you can hear it, even in the Outback. Keeping some of those empty suitcases up there prevented this, but it’s just one more reason to take the roof carrier off when not using it.

Fuel economy would be the other. While I didn’t do a scientific carrier-on, carrier-off fuel economy test to generate numbers I’d feel comfortable reporting, in-car MPG meters definitely went down. Consumer Reports found a 13% reduction in an actual scientific test.

Of course, much of the above applies to every roof carrier to some degree. What doesn’t is the availability of the CBX Solar, a variant of the CBX 16 that adds solar panels to the casing that power a pair of USB ports inside. It’s good for a 5-volt output. I managed to recharge an iPhone6 from 42% in one hour, 42 minutes while simultaneously recharging a portable 74-Wh battery pack. That would take many more hours to fully recharge from empty, but is the sort of thing the CBX Solar is intended for. Yakima envisions owners locking away battery packs, cameras, phones or other devices to recharge during the day while hiking, biking, etc. away from the car and camp site. This, as opposed to running the car to do so in the evening, or leaving behind a solar-charging unit and your devices to be stolen.

How appealing is that concept? My various hiking, biking and camping friends weren’t exactly wowed by the idea, but then sometimes innovations have to be experienced to be appreciated. The real issue is price: The CBX Solar goes for $1,299 versus the otherwise identical CBX 16’s $849. For at least one point of comparison, a BioLite SolarPanel 5+ with a 5-watt output goes for $89.95 at REI and includes its own battery pack. Again, that doesn’t offer any security, nor do any other accessory solar chargers.

So, the value of the CBX Solar is questionable, but even Yakima admits it’s a first step toward future solar offerings with greater capability. It’s a test balloon. The basic CBX 16, however, is unquestionably functional in terms of capacity and ease of use, while looking like no other roof carrier out there.