Thule makes great gear, but almost all of it only applies to lightweight bikes and wont be suitable for the large capacity assisted bikes that we distribute.
The 918 can take two ebikes easily however, with batteries mounted. It comes at a price that is tempting because the quality is so good.
Thule lists the 918 for $1050rrp but we discount it down to $960. They also have a ramp that goes on the rack for $89 rrp more. Shipping is only 25 dollars, nationwide.
Note that this fits very snugly on the Euro 50mm tow-ball shich is widely available at leading auto parts stores. That costs less than 20 dollars It fits less snugly on a 2" ball. You should test this out for yourself and go accordingly.