Choosing a Crossbar Shape and Style

Crossbars come in a handful of different shapes and sizes. Even once you have the compatibility with your vehicle figured out, there are often still some options to decide on! Here we will focus on the different crossbar styles from the two main roof rack brands that we carry, and are the leaders in vehicle fitment, Thule and Yakima. 

Classic Round & Square Crossbars

Thule square bars and Yakima round bars have been around for a long time. The 1 ¼” x 7/8” “square” bar shape is even used by other manufacturers, such as Inno. 
The benefit of these traditional crossbar shapes is that just about any accessory carrier that uses some kind of clamp will fit on them. Some older racks even have attachment hardware that only fits these styles of bars. Round and square bars generally cost at least a little bit less than their aerodynamic counterparts, at the expense of being less sleek and potentially making more wind noise on the roof. 

For tower compatibility, the current Thule SquareBar Evo can fit the current Evo towers just like their WingBar Evo counterparts (with the exception of Edge towers, we’ll get to those). For more information on the different generations of Thule square crossbars, check out Thule Load Bar vs SquareBar Evo. Meanwhile, Yakima RoundBars require the RoundBar SL Adapter to fit current Streamline series towers. 

Aerodynamic Crossbars

Aerodynamic or aero bars have evolved considerably over the years, but we’ll focus primarily on the Thule and Yakima styles available in 2026. Aero bars generally cost more than round or square bars, but they offer a sleeker appearance and, at least in theory, should make less wind noise. Note that wind noise is subjective, and as soon as you start adding accessory carriers, those will generate more noticeable wind noise than the bars themselves might. 

The current Thule aerodynamic crossbar is the WingBar Evo. This aluminum crossbar is available in various sizes in black or silver, and has a T-slot across the top for mounting accessories. It is shaped quite similarly to the previous AeroBlade, but has a slightly updated profile and a different T-slot. The T-slot is certainly the sleekest way to mount accessories, but not every accessory carrier has a T-slot option, and sometimes the T-slot hardware is an additional cost. One significant perk of T-slot mounting is that you can position the accessory carrier directly over the tower without around the bar clamps interfering. Accessory carriers that mount with clamps must have universal style mounting hardware to fit around the bar. Older racks designed to fit round or square crossbars may not have hardware that can be adapted to aerodynamic crossbar shapes. 

Yakima has two different aero bars in their lineup, the CoreBar and JetStream bar. They are shaped similarly, but the premium JetStream is an aluminum bar available in black or silver, while the CoreBar is steel and available only in good ol’ black. JetStream has a T-slot across the top that works with most T-slot compatible accessories, and can also accept universal clamps. The CoreBar only works with accessories with universal clamps. The CoreBar is the midpriced option and the JetStream is top of the line. These crossbars come with the appropriate adapters to attach them to Yakima StreamLine series towers, but they are also available as replacement parts (8880639 CoreBar adapter, 8880637 JetStream adapter). Also note that while shaped similarly, they are not identical and use different replacement endcaps (8880640 CoreBar endcaps, 8881490 JetStream endcaps). For more information on older Yakima accessory carriers and crossbar compatibility, check out Decoding Yakima MightyMounts and Snap Arounds. 

A subset of aero bars includes heavy duty or HD bars. The Thule ProBar Evo and Yakima HD Bar are both aluminum crossbars, but they move away from that wing shape used by the other aero bars. These are designed for truck beds and trade applications with increased weight capacities, but they can be used on standard roof racks as well if the length is suitable for your vehicle. They have T-slots across the top, but their profile might be too tall for the universal clamps equipped with some accessory carriers. To mount Yakima HD bars on StreamLine series towers, HD Bar SL Adapters must be purchased separately (not required for OverHaul use). Thule Xsporter and Xscape crossbars are even larger than the ProBar, but only compatible with those truck bed systems. 

Flush vs Through bar

This refers to the style of the tower as much as it does the style of the bar. “Through” bars are the traditional style of aftermarket crossbar system, where the crossbar extends through the tower, expanding the real estate available on your roof to carry more stuff. If you want to carry even more stuff, you can typically size up your crossbar length by at least one size. This increases the opportunity to hit your head on the bar when getting in and out of the vehicle, but sometimes it is a worthwhile trade off if you need to carry multiple bikes or boats. 

“Flush” bar style roof racks include the Thule Edge and Yakima FX series racks. These crossbars do not extend through the tower. The Thule Edge system uses a version of the WingBar Evo combined with Edge towers, and the Yakima FX bar is a JetStream construction. You lose some space for putting accessory carriers on the roof, but you get a more factory or OEM style appearance. When selecting flush bar sizes, it’s not uncommon for the fit guide to list a longer crossbar for the front than for the rear. This is normal, but close attention must be paid to ensure the correct bars are selected and installed. Because flush style crossbars are not supported as fully by the towers, they are often not approved for rooftop tent use.

Have questions or not sure which roof rack is right for you? Check out Basics of Using Fit Guides or contact us here!