Thule has developed the Xadapt adapter kits as the solution for connecting certain Thule Watersport racks, Thule bike racks, Thule Cargo Boxes,  and Thule ski & snowboard racks to the aluminum Thule Rapid Aero load bars, Thule 422XT Xsporter Multi-Height Aluminum Truck Racks, Thule 342 Cap Rack Systems, Thule Pro Series commercial truck racks & van racks, and most european factory rack systems that have silver elliptical bars with a channel in them & are found on certain model Volkswagen, Audi, Saab, BMW, Volvo cars etc.

The need for Xadapters began when Thule started manufacturing multi-purpose systems that did not use the traditional steel Thule Square load bars.  The new european styled elliptical Rapid Aero load bars that Thule designed for use on the Thule Rapid Series multi-purpose base rack systems include a t-slot channel that runs along the length of the bars.  The Thule Xadapts insert in the t-slots and the Thule gear carrier is then mounted to the Xadapts.  

The Thule Pro Series commercial truck racks & van racks and the Thule Xsporter truck rack bars also have t-slot channels in their load bars that the Xadapt Kits can slide into.  The european style factory roof rack systems found on many Volkswagen, Audi, Saab, BMW, Volvo cars etc also have t-slot channels that the Xadapters are compatible with.

It is important to note that Thule Racks is constantly engineering new gear carriers and upgrading current ones so that they can install directly on both factory rack crossbars as well as on these base rack load bar styles without the need for Xadapt Kits.  Hence, we highly recommend reading the product details on each Thule gear carrier product page to determine mounting requirements.  Additionally, we suggest clicking the link below to view compatibility specifications of the most popular roof mount Thule gear carriers when used on various base rack crossbars:

Thule Xadapt fit guide