I have done a lot more testing of kayak racks on the TracRac truck rack system, since TracRac has hlated production of their own kayak carrier (not certain if they will be releasing a new product in the future or cancelling a TracRac kayak rack offering altogether). The kayak carrier option has always been a very popular request with TracRac truck rack owners, so I checked out what other car rack / truck rack companies have kayak racks that are compatible with the Trac Rac crossbars.
Thule Racks is the clear winner here. Basically, any Thule watersport carrier that has universal fit hardware will work, providing the longer bolts included with the
Thule Xadapt3 kit are used in combination with the universal fir hardware on the following Thule Racks watersport carriers:
Thule 554xt Hang-Two surfboard rack
Thule 830 Stacker kayak rack
Thule 835Pro Hull-a-Port kayak rack
Thule 835xtr Hull-a-Port kayak rack
Thule 875xt Hydro-Glide kayak rack
Thule 878xt Set-to-Go kayak rack
Thule 881 Top Deck kayak rack
Thule 883 Glide & Set kayak rack.
The Thule 579xt canoe rack and Thule 877xt RollerCoaster kayak rack roller do NOT work on the TracRac cross bars.
Yakima kayak, canoe and surfboard racks do NOT work on the TracRac truck rack bars.
SportRack kayak racks do NOT work on Trac Rac bars either.
Have not yet tested the Malone kayak rack carriers on the TraRac cross bars.