Have new 2007 Honda Accord roof rack with Thule 400XTR but unsure if 518 echelon fits

[mollyk9]

I really like the look and design of Thule Racks new 518 Echelon bike rack. The problem is I just bought the Thule 400XTR Rapid Aero system for a 2007 Honda Accord roof rack. I'm confused if the 518 Echelon will work on the elliptical bars of the 400XTR because they aren't shaped like the traditional square Thule Rack cross bars.

[rack your brains]

Yeah I noticed the Thule Racks corporate website doesn't have much information posted currently about the compatibility of the Echelon with the elliptical shaped Thule Rapid Aero base rack bars, or if it works with factory roof rack crossbars for that matter. I poked around though and discovered that Thule Racks has released the Xadapt 9 kit. This is an adapter kit with all hardware included that enables the 518 Echelon bike carrier to connect to the Thule Rapid Aero style crossbars that you have on your 400XTR system (these elliptical shaped bars are also found on the 450R Rapid Crossroad & 430R Rapid Tracker II car rack systems - plus the 421 / 422 Xsporter truck racks). By the way I know this doesn't apply to you mollyk9, but the Echelon also works on factory racks when you use the Thule 532 RideOn adapter set.