"U-Hitch" Rear Hitch Receiver

[Tim Ryce]

Hi All,

I've had a long read through all the posts discussing adding extra weight to the rear of a trailer; knowing the awareness required in maintaining safety, I've vowed to always minimize the amount of weight hanging off the back of my 13' Trillium. Given that I'm never going to be putting more than two road bikes (< 25lbs each) on a bike rack (~40lbs) back there, I'm looking into options for putting a 'light use' receiver on the rear bumper. I'd like to avoid the costs of having a 'full-duty' receiver welded onto the frame.

Given all this, what's the general opinion of a "U-Hitch", something like in the link below? I worry about the torsional effects acting on the bumper, as it only has the one mounting point...
http://www.sk8shop.com/reveuhi1.html

(sorry about the overly-busy webpage; it's the only one I could find that has a good picture online)

Any comments/suggestions would be appreciated.
~Tim

[Greg A]

I would think the torque forces of carrying even light bikes and the weight of a rack would eat the bumper alive with this hitch, at least looking at the bumper on my Scamp.
I'm sure some of the more engineering minded fellas will jump in here shortly.

[Booker B.]

On our trillium there is a cross bar on the frame behind the back wheels. Our bike rack is mounted to that and then to the back bumper so that there is less chance of the bounce/twist force that would tear apart the bumper. However, we put two kids bikes on it only and even then I found the nuts would loosen on an extended drive.

We put 4000 miles on the trailer with the bikes on it last summer and we had no issues. As I have mentioned in a previous post placing a battery onto the tongue offset the weight at the back.

[Tim Ryce]

On our trillium there is a cross bar on the frame behind the back wheels. Our bike rack is mounted to that and then to the back bumper so that there is less chance of the bounce/twist force that would tear apart the bumper.

Booker, do you have any photos of your install? I have the same angle-iron cross-member directly underneath the dinette/bed; I suppose I could fabricate a bolt-on system for an extra-long 2" receiver...

[Casita Greg]

Hi Tim,
Just my personal experience with "bolt-on" hitches... While they are themselves constructed fairly substantially in their own right, you also must consider the torsional (twisting) load and the lever arm force (the leverage factor which becomes more pronounced the farther away your load is from the fulcrum point, aka hitch). It is fairly common that people who have used these bolt-ons have experienced catastrophic failures with them. The failures were not the fault of the hitch device, but of the really thin (tin foil seems to come to mind here) 4" sewer hose bumpers. They really have the strength to only carry the sewer hose and little else of any weight. All of the trailer manufacturers will tell you they do not recommend adding these devices to the sewer hose bumpers for that reason. They will just fold up on you and at your next fuel stop walk-around you'll find your expensive bikes half worn away from abrading on the pavement like a giant belt sander. If you really see no alternative to replacing the rear bumper with a good solid piece of heavy-walled channel tubing, it would be best to have your load mounted as close as possible to the hitch receiver. It probably wouldn't hurt to add some additional bracing to the bumper tube to reinforce it. Welding is best, but drilling and bolting would also work to help strengthen the whole setup. I sawzalled my 4"sewer bumper off and welded a 5' section of heavy wall square 3" tubing on in its place. Additionally, I added a section of 1 1/2" square tube underneath between the main frame members just forward of the rear bumper and welded a 2' piece of receiver tube under the bumper and the 1 1/2" tube for added strength and stability. I now carry my "trunk" in the new receiver without worry. In fact, if it wasn't illegal, I could even tow another Casita behind it as well.

[Vic&Kathy]

I did essentially what Greg did, attached a receiver to the bumper and extended it all the way to the first frame cross member. It's solid, ain't going no wheres no how. Our Yakima hitch rack can be slipped on in moments and it is a breeze to use.

But with two bikes on it our '72 Trail Mite has gotten a little squirrilly. Not such an issue when I'm pulling it with my big old Suburban (we call it "the beast"). But Kathy had a nervous moment last summer when it did the hula while she was pulling it behind our Tacoma. Luckily it didn't waggle hard or long and she was able to continue on without incident.

But now when the tow vehicle is the Toyota or the Isuzu Trooper, bikes go on the Toyota's roof rack and/or in the truck bed.

Vic

[Tim Ryce]

Thanks for the replies, all. Sounds like the concensus is:
A- Avoid the little bolt-on "U-Hitch" thingys at all costs
B- Be aware of the limitations of your rear bumper
C- Be aware of the load balancing, and ensure adequate tongue weight

I think I'll explore further the set-up that Booker B. went with: a bolt-on receiver connected to the rear bumper (already beefy on a Trillium), and the floor support strap just aft of the axle. I'll report back with photos when it's all said and done.

~T

[Casita Greg]

Vic,
Good point to bring up. It is important to not forget that the trailer's tongue weight should always be between 10% - 15% of the trailer's total weight. This figure will be somewhat different for each individual trailer, and can be greatly affected by such things as distance from the wheels to hitch length, length aft of wheels, and by the trailer loading configuration (both what's installed and what's carried).

Fishtailing is generally caused by too light of a tongue weight, so please take into account any weight shift changes that will be created by adding such additional loads, particularly at the rear of the trailer. Any changes will be less pronounced by moving the load closer to the wheel area, and likewise the further from the wheel area you move any given weight, the more effect it will have on overall weight distribution. Sometimes loads can be counterweighted by moving heavy items (like batteries for example) to different locations. Putting the battery, or other heavier items, on the tongue will help to counter the added leverage of the additional load on the rear of the trailer. This hasn't been much of a problem for me personally because, as those of us who have them know, Casita trailer tongue weights generally run a little on the heavy side as it is, but light weight trailers will notice more pronounced handling difficulties by not properly maintaining the 10% - 15% weight requirement on their hitches. Hope this helps.

[BobB]

Here is a link to a previous thread on the same subject. One of the most important factors is preventing oscillations and failure due to metal fatigue. Jim and Carol attached a strut to the belly band on their Casita to stabilize their bike rack. This is one way to keep the set-up from being too heavy.

http://www.fiberglassrv.com/board/index.ph...amp;hl=receiver

My own preference is to carry my bikes inside the SUV, but I realize this won't work for everyone.

[Pete Dumbleton]

I don't see the mechanical problem with the equipment shown IF the bikes or rack are fastened to the egg wall at the top so there is no rotation or torque on the bumper, just a vertical load -- This also holds true for a full receiver on a welded and braced bumper.

Personally, I would have a rack on the tongue that sat above the battery box - LP tank. Keeps the weight in a better place, loadwise, and keeps the bikes out of the road debris eddy at the trailer's rear.