Bumper Stability

[fendr1962]

I have a 2020 Freedom Express Ultralite 196RBS. I want to mount a bike rack (two bikes) on the 4x4 bumper. I understand the standard stock bumper is not constructed to handle anything being mounted on it. So I am planning to purchase a stronger bumper and having it installed along with extra support brackets bolted to the I-beam frame. Does anyone know what mil thickness the factory bumper is? And what mil thickness should I purchase to give me the support I need? The weight that I will be adding to this bumper will be only about 200 pounds. That's including the receiver hitch, bike rack, and two bikes. And the bike rack has the feature that allows me to tighten the hitch where it goes into the receiver to prevent up and down, and sideway motion.

 

[Kevin D Pem]

I have a 2020 Freedom Express Ultralite 196RBS. I want to mount a bike rack (two bikes) on the 4x4 bumper. I understand the standard stock bumper is not constructed to handle anything being mounted on it. So I am planning to purchase a stronger bumper and having it installed along with extra support brackets bolted to the I-beam frame. Does anyone know what mil thickness the factory bumper is? And what mil thickness should I purchase to give me the support I need? The weight that I will be adding to this bumper will be only about 200 pounds. That's including the receiver hitch, bike rack, and two bikes. And the bike rack has the feature that allows me to tighten the hitch where it goes into the receiver to prevent up and down, and sideway motion.

Wow! Do we have an engineer that wants to run the numbers? I always over build. I sit back and consider as many factors as I can. You know, weight, wind, what kind of terrain I travel, and the occasional pot hole I don't miss.
The short! over build.

 

[Bob K4TAX]

I have a 2020 Freedom Express Ultralite 196RBS. I want to mount a bike rack (two bikes) on the 4x4 bumper. I understand the standard stock bumper is not constructed to handle anything being mounted on it. So I am planning to purchase a stronger bumper and having it installed along with extra support brackets bolted to the I-beam frame. Does anyone know what mil thickness the factory bumper is? And what mil thickness should I purchase to give me the support I need? The weight that I will be adding to this bumper will be only about 200 pounds. That's including the receiver hitch, bike rack, and two bikes. And the bike rack has the feature that allows me to tighten the hitch where it goes into the receiver to prevent up and down, and sideway motion.

Well as I view things, the 200 lbs are not the only thing to consider. Most bike racks I've seen while attached to the bumper actually place a moment of arm aft of the bumper. So there is the twisting moment to be considered. If the weight is 200 lbs and the moment applied is 12" aft of the bumper then the moment is 200 ft-lbs. If it is 18" aft of the bumper then the moment is 300 ft-lbs. Also, adding weight to the aft of the trailer will reduce the weight applied to the hitch of the tow vehicle. Likely not a big deal but when doing the numbers, do ALL the numbers.

If it weren't raining, I'd go measure the thickness of the stock bumper material. Sorry but I don't cater to sloshing around in the rain today. Maybe tomorrow.