I read that my White Hawk's bumper rating is 100lbs causing me to find an alternative bike transportation method. On my previous trailer, I used a bolted on 2" receiver hitch with a 4 bike carrier. We are a family of four but little sister is only a passenger right now. When researching carriers, I came across this roof top option
for $35 - $40. My suburban comes with cross members so installation wouldn't be a problem. The first time I bought the a carrier, I opted for a receiver hitch because of the convenience of loading and unloaded. Now with weight restrictions, I opted for a safer solution.
I purchased 3 as it would be several years away before little sister will have a big enough bike that it can't be transported inside the tow vehicle, on the ladder, etc. I installed them in about 45 minutes in the dark. I am very pleased with them and should be able to load and unload without a ladder (but with another adult's help). I can heft big brother's bike up there but mine and mamma's bike will need someone pushing from the ground. I set the holders as far forward as they could go so I can use the passenger seats as a place to stand.
The locks use matching 207 keys. The nuts are 10mm and the bolts are 11mm. I hear no change in sound while driving around (without bikes loaded).