Quick Spin: Thule Ascent 1600 rooftop cargo box, July 2, 2008

Instant extra room

The Thule Ascent 1600

The length of the Ascent 1600

The capacious interior

That monstrous carrying capacity

Cleverly designed hinges

Soaring fuel costs have hit everyone hard and even US drivers are finally beginning to emulate the Europeans by downsizing their vehicles. Cyclingnews technical editor James Huang checks out one of the best options for when your small car needs to emulate a big one.

The Thule Ascent 1600 is the third-largest of four models in the company's newest line of roof top cargo boxes that range in volume from 11-17 cubic feet (312-481L). Our Ascent 1600 falls just shy of the top model in terms of volume at 16 cubic feet (453L) but its slightly squatter dimensions makes it a good fit for smaller SUVs, smaller cars/wagons and so-called 'crossovers' whose more economical operating costs have recently become so popular in North America.

The plastic-shelled Ascent 1600 is reasonably lightweight at 37lb (16.8kg) but its unwieldy bulk makes for a somewhat tricky one-person installation job. It's definitely possible, though, and Thule's scissor-like Quick Grip hardware makes for easy and secure clamping on a wide variety of crossbars once the box is properly positioned.

Bottomless pit of space

The wider and taller dimensions that make the Ascent 1600 such a good visual fit on our Subaru Forester test vehicle also makes for more usable interior space than a longer and narrower box that is intended more for skis and snowboards. The 76" (193cm) maximum length can still easily handle most winter sports gear but was most adept at swallowing mounds of overstuffed duffel bags and camping gear that all-too-often accompany weekend trips to races and other events (think 24 Hours of Moab). Loading all that gear is also pleasantly easy thanks to the spring-assisted top that opens from either side of the vehicle while the included lock cores keep things reasonably secure, too.

On a more bike-specific note, the generous width also takes up the entire crossbar span front and rear on our test vehicle, meaning there is no space leftover for bicycle trays. Vehicles fitted with longer crossbars that hang over past the towers might be able to get around this issue a bit but it's definitely something to keep in mind. Thankfully, we were equipped with a hitch-mounted rack so it was a non-issue in our case but others might consider something a little narrower.

A bit thirsty but worth the extra gulps

Unfortunately, those squatter dimensions that yield so much usable space also produce more frontal area that takes its toll on fuel economy. We noticed only minor losses in city driving but up to a 20 percent hit at highway speeds (keep in mind that different vehicles will likely yield different results). On the plus side, the box's reasonably aerodynamic shape (which includes 'diffuser technology' on its underside) produces only moderate wind noise, even through our test vehicle's giant glass moonroof panel, and probably prevents the fuel economy from being even worse.

That drop in gas mileage was greater than we expected but we still wouldn't hesitate to recommend the Ascent 1600 to consumers that occasionally need some extra space. In fact, the additional 16 cubic feet afforded by the roof top cargo box roughly turned our compact Subaru Forester into a full-sized Ford Explorer (at least in terms of storage capacity). While adding the box also correspondingly increased our fuel consumption almost to the same level, the Ascent 1600 still let us decide when that extra space was needed without having to put two vehicles in the driveway.

Price: US$379
Pros: Gobs of usable interior space that is easily added only when you really need it, reasonably quiet at speed, included lock cores, dual-hinged top
Cons: Takes up a lot of room when removed from vehicle, leaves little-to-no crossbar space for bicycle trays, noticeable drop in fuel economy
Cyclingnews rating:

Photography

For a thumbnail gallery of these images, click here

Images by James Huang/Cyclingnews.com

• The Thule Ascent 1600 offers a convenient means of adding more storage capacity when the need arises.
• The length of the Ascent 1600 is designed to complement smaller wagons and SUVs but other sizes are available.
• The capacious interior swallows a surprising amount of gear.
• That monstrous carrying capacity also takes up a lot of rooftop space, though, leaving no room for bicycle trays on our test vehicle.
• Cleverly designed hinges are spring-loaded and allow the lid to open from either side.
• Included locks offer a bit of security.
• The versatile jaws can accommodate nearly any size or shape of crossbar…
• …and their positions are easily adjusted via the handy interior knobs.