What is the correct kind of hitch receiver that works with my bike rack?
As Daniel R Hicks writes, any sturdy 2&quot; receiver hitch should work, ** as long as it fits your car **. Hitches are usually specific for one or a few car models.
Hitches are designated according to the width of the square receiver opening. 1.25&quot; hitches are typically lighter than 2&quot; hitches, but are also less robust and can't support as much weight. Since you are getting a heavy-duty rack to carry heavy e-bikes (80 lbs/bike max vs. 35 lbs/bike max on a &quot;normal&quot; rack), you need the strength and weight capacity of a 2&quot; receiver hitch.
As mattnz notes, a bike rack slotted directly into a hitch receiver will generate higher torque forces on the pitch axis (rotating forward/back) than would be the case with a standard tow ball/trailer combination. The hitch needs to be even beefier to withstand these higher torque forces.
The hitch specifications will probably indicate a maximum &quot;tongue weight&quot; which is the maximum weight pressing down on the end of the hitch that it is rated to hold up. The larger the tongue weight rating, the better, as the weight of the rack and bikes will essentially be tongue weight.