Today I mounted my valley hitch (2" Class 3).Instead of the supplied hardware I used:
2- 6" X 2" 3/16 steel plates with the same hole pattern as the hitch($20 at my local welding shop.(painted at home with a spraycan)
4-7/16 X 5" Grade 8 bolts with 3 - each washers and nylon locknuts( $7)

I also used the u bolt supplied with the hitch.I atached the hitch with the u-bolt to the tie loop.Then raised the hitch ends to the frame and stuck the bolts through from the outside to the inside putting 2 flatwashers on each bolt first. I then put the 2 X 6 plate over the bolts on the inside of the frame and put 1 washer and the nylock nuts on .Tightened everyyhing up and good to go.
The install took 15 minutes and seemed a lot easier than modifying the frame or whatever needs it to fit the little tabs.No cutting or grinding or sanding. It looked like the hitch already had the sides spread out a little to fit the frame.
It seems to sandwich the frame tube nicely and is much stronger than picking up one side of the frame tube.
The holes drilled in the plate were 1/2 " to give some room for error as I wasn't sure of the tolerance on the frame holes from oinside to outside.I did not elongate the holes as the ones on the hitch came.

So your bolts span the full width of the U shaped frame members?

I believe the normal Valley installation just tightens the bolt to the outside face of the frame member. The Honda hitch uses plates with spacers, while Hidden uses some sort of sleeve on the bolt. Note that these 3 mounting methods, while different, do not put pressure on the two faces of the frame member, pushing them together. They grip only one side of the frame.

If I understand your mounting method correctly, you are squeezing the two sides of frame member together. I do not think that is secure. There is a serious potential of distorting the frame member. This could either break welds, or loosen your bolts.

I would suggest that you have a professional look at your installation.

paulj

You make a interesting point. I looked at it with a couple engineers as we design aircraft modifications at work.
The hidden hitch Class 1 has a bolt running from the hitch flange on the inside of the member to the outside where it is fastened using the long spacer and a washer. This would put a lot of side loading and flex on the outside wall of the frame member.Possibly weakening the welds and distorting the tube.That said, it is the only hitch class certified for use with the element.
The valley Class 3 hitch has the flange on the outside of the frame and attaches to the outside only. Much better but still only twisting from one side.
This hitch assembly also exceeds the recommended weight usage of the frame on the element so we are in the grey area right off the get go.
By sandwiching the frame tube the load is more equally distributed to the frame but yes the frame may be prone to distortion. More than putting all the load on one side? Probably, but can't be sure without spending way too much time on it. I am guite sure it is stronger than the little loop that the hitch picks up on that is welded to the spare tire holder. The bolts came up tight without any measurable distortion in the frame tube with a digital caliper. I really don't know how strong the welds are holding the tube together so really it is impossible to anylyze. We figure the first sign will be loose bolts then I will put a spacer inside spanning the inside of the tube. I think the welds on the spare tire bucket loop will break first.
The hitch is being used for a 4 bike Sportworks T-2 rack so there is a fair bit of torque on it and no pulling weight.If I have to change it I will post. The original assembly for the valley hitch seemed kind of hokey and I suspect it is much cheaper . Smaller bolts and no sideplate. The Class 1 (took it off) probably had to be that way as the holes on the inside of the tube are bigger than the outside. They should have made the hitch flange to the outside. Anyway,,, Back to work designing a wing mod for a single otter.

Let me be the first to exclaim,

This thread is worthless without pictures!

Here's a thread with links to installation instructions (and drawings) for the 3 hitches:
http://www.elementownersclub.com/forums/showthread.php?t=7867

I am guessing that the holes on the inside panel of the frame were intentionally made larger to accomodate the hitch installation. In other words, I thnk the Honda hitch, with its separate 'stays' with built in collars, was designed at the same time that the holes were specified for frames. I suspect the Honda mounting system is more complicated than necessary, but it may be the strongest of the three.

I also suspect that fishing a bolt though one hole into a box structure is common practice in the trailer hitch industry.

The hitch itself is a rigid structure, so there are few twisting forces on the mounting bolts and frames. The bolts are probably working in shear. In the Honda hitch, the pins on the stays should transfer some of these shearing forces to the inside panel of the frame.

I suspect that the U bolt and 'tow loop' together can support quite a bit of the trailer load. That 'tow loop' mounting area is well enough reinforced that it can take half of the weight of the Element - it is the preferred floor jack lifting point in the rear.

The frame mounts are still needed to handle the lateral and twisting forces on the hitch.

You probably have taken the necessary steps to insure that this change in mounting method does not produce problems. Details like measuring the deflection, and the use of lock nuts are reassuring.

paulj

It seems to sandwich the frame tube nicely and is much stronger than picking up one side of the frame tube.
I have installed hundreds of hitches in the past, while employed at a shop that installed them.

I have never seen or heard of this method of installation on a unibody frame.

While I have no data to back it up, my first thoughts about this install are not positive. Part of the strength that is acquired with the standard installation method results from the "clamping" of the frame between the hitch and the plates. Your install does not retain this. The "plate and carriage bolt" method that is used with the Valley hitch is commonly used in the industry.

If you install according to instructions with the Valley hitch, very little frame material actually needs to be removed from the existing access holes, less than 1/8 inch, and can be touched up with paint after installing the hitch.

While you have not stated that you would tow a trailer, if you were to actually tow a trailer with your setup, I think that your frame holes would start to elongate with enough cycles of braking and accelerating.

I would suggest talking to someone at a hitch manufacturing company about your modification, such as Draw-Tite or Rigid Hitch.

Added Picture - see below...

I just installed the Valley Class III hitch on my Element. I followed the mfr instructions, although it wasn't clear exactly how to "widen" the access holes (to fit the carriage bolt and plate through the hole). I opted to use a Dremel tool, and cut a 1/8 inch slot extending from the hole at the 9 o'clock position. (see pic below) This minimized the cutting, and was adequate to barely fit the plate and carriage bolt through. Worked like a charm!!! I would not recommend widening the entire hole (as in drilling)... Besides, I don't know how you'd get your drill in there without a flexi-drive attachment. If you don't have a Dremel, borrow one! Or I suppose you could use a mini hacksaw to cut the slot.

GREAT HITCH, and only $130 at eTrailer.com ($145 with shipping, arrived in about a week.) If you're outfitting it with a bike rack, I would STRONGLY recommend the Allen 640RR (4-bike carrier). This is made for vehicles with an externally-mounted spare tire, so it extends out a bit further. On the Element, THIS ENABLES THE HATCH AND TAILGATE TO OPEN without removing the bike rack... (see pics below) THIS IS AWESOME!!!! I have owned this rack for over 2 years, and it is EXCELLENT quality! On my Montero (before owning the Element), I had to tilt the rack down to open the back door, and even then the door only opened about a foot... pain-in-the-neck! Plus this was near impossible to do with bikes on the rack. On the Element, NO NEED TO TILT!!! The Allen 640RR costs around $150 on-line.


:grin:

To follow-up on what E-nigma said. Not only would I never want to tow with this setup I question using the bicycle carrier hanging off the hitch setup in this manner.

The Sportworks T-2 Bicycle carrier for 4 bikes is not light by itself. Adding 4 20-50# bikes will add quite a bit of weight to the hitch. The bouncing down the road will eventually elongate the 4 holes up and down just as it would lenghten them if towing. If you both tow and use a heavy bike rack then the holes will increase in size in all directions...