For a square crossbar set the longest we have is the 60" Thule SquareBar Evo # TH712500.
The longest crossbar available is the 80" Yakima CoreBar Crossbar # 8880656 which comes as a single crossbar, but we also have the 79" Thule ProBar Evo Crossbars # TH713700 which are a bit more heavy-duty.
This is longer than even the ladder rack crossbars so you'll be hard-pressed to find something longer than that. If you let me know what you're planning on using this for I can see what else you... view full answer...