Light Duty Front-Mounted 2" Receiver

[rollinghome]

I may upgrade to a heavy duty receiver at some point (like this one) but for the time being I just needed a quick, cheap, light duty solution to accept my bike carrier while I'm towing a trailer across the US. I wanted to keep it light in weight with a minimal decrease in ground clearance. I also wanted the install to look clean and unobtrusive with the option to easily remove it in the future. Fabrication and painting is complete but snow and other projects have delayed installation. I'll post more pics after the install.

The receiver mounts to the center of the sub-frame (1999 AWD Astro) using the existing center hole for the bolt attachment. A length of rebar was welded to the nut to "fish" it into the sub-frame and hold the nut while turning the bolt. I used a 3/4" grade 8 nut, bolt and lockwasher. A metal coat hanger was used to determine the rough shape of the sub-frame. The 3 pieces that "cup" the sub-frame were then spot welded and test fitted before final welding. Voids were intentionally allowed in the rear portion of the 2" square tube to allow debris to exit. A square plastic section at the bottom of the bumper was removed to allow the highest possible mounting of the receiver.

My swing-out Yakima bike carrier is fairly heavy so I hope this will support its weight! Let me know if you have any questions.

[mdmead]

Given your needs, that looks SLICK! Can't wait to see the installed pics! (Love the rebar on the nut idea!)

[LiftedAWDAstro]

While that 3/4" bolt is strong, I would be worried about the strength of the steel in the subframe. Can you add a piece of flat stock to the inside that you then put the nut over? If not I would think about adding a couple 3/8 or 1/2" bolts through the rear. You can drill and tap so you don't need to worry so much about the nuts.

[rollinghome]

You bring up a good point. The easiest way to add flat stock to the top side would be to weld it to my nut/rebar apparatus. Drilling and tapping the back isn't a bad idea but I was hoping to avoid drilling into the sub-frame. I'm moving to Maine and the salt they pile on the winter roads LOVES to crawl up into spots like that and wreak havoc. In addition to that I don't have a tap and die set.

I'm going to check the thickness of the sub-frame around the center hole, if it's looking sketchy I'll rework my bolt adding a piece of flat stock to it. Thanks for the suggestions!

While that 3/4" bolt is strong...

[BBSig]

Let us know how it works. Looks like a slick idea.

[Astrophysics]

Hi and Happy New Year. I like the idea of mounting to the subframe since it already has a center hole and as I recalled a hole on each side. One time a couple years ago on my 2003 AWD Astro, I mounted a heavy 1/4 inch steel plate to the under side of the subframe cross member using all 3 of the holes. I think it was seismic grade Simpson Strong tie or similar. I had then mounted recovery hooks to the flat plate. More recently, at the time of my 2 inch lift kit installation, I installed a auxillary 2" x 1 1/2 " steel box tube behind the bumper. I hope to mount a light duty 1 1/4 inch trailer hitch receiver to the cross bar.
In general on your design, you could add some diagonal Simpson strong tie pieces from your receiver up to the bumper mounting bolts or just drill a hole in the frame highter up. It is important to provide some triangularization to give you receiver a stiffer bending moment, etc. Just like a shear wall on the garage keeps the stud wall from twisting, you need to add some more support. When you look at a typical rear trailer hitch installation, you will notice it provides structure to keep it strong for the horizontl pulling force (which you have in your design) and it provides a verical strength member for the "tongue weight of the load (your bike rack).
AP

[Astrophysics]

view of bumber mounting bolts. Originals are metric 10 mm or 12 mm?

I drilled one extra hole in frame to allow the recovery hook from S10 Chevy Blazer to bolt on and use one of the original bumber mounting holes.

I will look for photo of my old recovery hook that was posted on the site a couple years ago.
the old design is where I used heavy steel plate bolted to subframe cross member.

AP

[Astrophysics]

found the steel plate photo showing the cross member and the 3 bolts etc...

AP

[rollinghome]

That old plate system looks hardcore! If I ever intend to use mine for anything more than light duty applications I would just go with something similar to the setup I linked at the beginning of the thread (from "LiftedAWDAstro"). Your recovery hook setup does look nice though.

Here's my updated nut assembly. I'll start repainting tomorrow and hopefully install in a couple days.

[Astrophysics]

Nice job with welding. You can also use some thin wire to pull bolts thru from above a blind hole like the way the shops fish bolts thru frame when installing trailer hitches.

What type of welder do you have?

AP

[rollinghome]

To be fair, I must admit that my good friend Jim welded everything pictured. I designed everything and he often gave suggestions to improve or aid in the design process. I have very little experience welding so my "work" tends to come out strong but "chunky". I recently fabricated and welded a spare tire carrier for my trailer. It wasn't as clean as this project but it still came out nice and I have no fear it will fail and kill me. I figured the receiver for the bike rack would benefit from a more experienced welder. I don't like the image of running over a front-mounted bike rack at speed while towing a trailer.

I opted for the bottom bolt and top nut/rod for a few reasons.

1. There are nice access holes on the side of that section of the sub-frame.
2. The rod would lock on the inside of the subframe while I was turning the bolt.
3. The bolt end (being on the bottom) would result in the lowest profile without having to grind off any excess bolt length.

My friends welder, which has been used exclusively on this project, is a 220V Millermatic Challenger 172. My welder is a cheapo Sears 110V MIG.

[rollinghome]

The good news: The receiver mounted in less than 5 minutes and looks great.

The bad news: It is not robust enough to support my bike carrier and bikes.

My design MIGHT have worked had I used a thicker piece of steel on the bottom of the receiver. The existing design would be bomber with the addition of one vertical support (as Astrophysics suggested). I've had too many delays to my move and I'm sick of painting in cold snowy weather so I'll be using a quick, temporary fix for this problem. I'll sort out a more permanent fix in the spring/summer (probably a full multi-point frame mounted receiver or if I get ambitious, a custom bumper with an integrated receiver and winch mount).

Here's my temporary solution. I'm going to install a cable tie that connects to the top/rear portion of my bike rack to both sides of my roof rack. My rack is VERY strong so this should prove more than adequate for my 3200 mile journey. Of course, I'll post pictures when it's complete.

[Smiliesafari]

If you weld it on it will be a bunch stronger. Weld both verticles and across the top. The material size is more than adequate to carry bikes.

[rollinghome]

Welding would make it strong enough but it would make removal messy. In addition it would create bare metal which I can't successfully paint in cold weather, bare metal that will soon be inundated by heavily salted roads in Maine.

[mdmead]

What about another big bolt on the front upright at the back of the 2" tube? You could push the bolt through and spin it with a long extension and u-joint. Backside with another nut/rebar combo. (And wow, that is a pretty big bike rack!)