Uhaul Hitch? - Page 3

wilkoturbo · #21 07-01-2008, 04:54 PM

what is uhaul has anyone got any pics cos i think i might have one fitted thats all thanks

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TowX · #22 07-01-2008, 05:07 PM

Sorry, I guess I don't see why so many folks are interested in these aftermarket hitches, when the factory piece is so robust. We buy expensive SAV's and then want to save $200 on a hitch? I've towed probably 50,000 miles with race car trailers over the years and I absolutely will not compromise on the hitch. I've been happy with Reese/ Valley/ Drawtite hitches on American trucks in the past but they were designed to bolt in just like a factory piece, and often times were the OE part, rebranded.

But for the X5, I looked at the Curt and Da'Lan hitches, and went factory. There was no way I was going to drill holes in my chassis to install an aftermarket part. And then have hardware hanging down too? the factory hitch may be $490 (I got my from my dealer for $410) but it includes the wiring interface box, plug and all wiring too. Truly is plug and play. And after having done the install myself (just just one person), I can tell you that this is a serious piece of hardware. 14 bolts and nuts holding it it! I've compared it to the other hitches, and they just don't compare in how robust they are.

Finally, let me say that I am absolutely not a BMW purist. I will consider any quailty part. (BSW Sirius and BT are now in my car for example, as is the H&R suspension.) But to shave a few bucks on a hitch is lost on me, unless you're just going to tow a 2,000 lb jet ski. But towing my 5000 lb 911 and trailer, no way I'd do it with a Curt, not from the installation instructions I saw.

OK, I'll climb down off my soapbox now, sorry.

JCL · #23 07-01-2008, 06:35 PM

Quote:

Originally Posted by Krunk Man

hmmm i dont have this bar. was it optional?

There have been various iterations of the non-OEM hitches over the years. Early ones attached to the rear sheet metal (unibody) only, without replacing the bumper struts like the OEM hitch does. There were a few problems because the hitch flexed (rotating about the attachment point). In extreme cases, this twisted the rear unibody and caused significant damage. Pictures have been posted previously on this site and others.

The response of the non-OEM hitch manufacturers was to include a strut running fore and aft from the receiver, along the vehicle centreline. This strut attaches to the rear subframe up close to the rear axle. It effectively stabilizes the hitch, but many consider it ugly, and it reduces ground clearance at the rear.

If you don't have the strut, you are probably OK towing lightweight trailers. The hitch rating isn't a guarantee, as the early hitches that twisted/rotated were all rated 6000 lbs as well.

trueX5er · #24 07-01-2008, 06:40 PM

Quote:

Originally Posted by wilkoturbo

what is uhaul has anyone got any pics cos i think i might have one fitted thats all thanks

http://dontuseuhaul.com/

edit: OK, after reading countless stories on that site, I would never ever get anything from u-Haul

Krunk Man · #25 07-01-2008, 06:44 PM

Quote:

Originally Posted by JCL

There have been various iterations of the non-OEM hitches over the years. Early ones attached to the rear sheet metal (unibody) only, without replacing the bumper struts like the OEM hitch does. There were a few problems because the hitch flexed (rotating about the attachment point). In extreme cases, this twisted the rear unibody and caused significant damage. Pictures have been posted previously on this site and others.

The response of the non-OEM hitch manufacturers was to include a strut running fore and aft from the receiver, along the vehicle centreline. This strut attaches to the rear subframe up close to the rear axle. It effectively stabilizes the hitch, but many consider it ugly, and it reduces ground clearance at the rear.

If you don't have the strut, you are probably OK towing lightweight trailers. The hitch rating isn't a guarantee, as the early hitches that twisted/rotated were all rated 6000 lbs as well.

Thanks JCL, great info
I currently have a 350pound bike on a hitch mounted carrier.

I loaded her up today and noticed a large amount of twist(of the hitch) from
the weight of the bike which sits about 1.5 feet out.
I'm guessing the added length makes 350 more like 600pounds.

looks likes this.

So would it be a bad idea to use it if im getting all this twist from the weight? You said serious damage has occured in the past...

JCL · #26 07-01-2008, 07:03 PM

Quote:

Originally Posted by Krunk Man

great info, I currently have a 350pound bike on a hitch mounted carrier.

I loaded her up today and noticed a large amount of twist(of the hitch) from
the weight of the bike which sits about 1.5 feet out.
I'm guessing the added length makes 350 more like 600pounds.

looks likes this.

So would it be a bad idea to use it if im getting all this twist from the weight? You said serious damage has occured in the past...

I wouldn't risk it, but that is me.

The OEM hitch has additional bracing, but let's leave that aside for a moment and consider the load that is being applied.

The rating of 6000 lbs is for a tow rating, not a hitch load rating. The OEM hitch (for which I have the data, so I will use those figures) allows a maximum tongue weight of 600 lbs, for on-road towing. Interestingly, there is a limit of 350 lbs tongue weight for off-road towing, simply because there is more vertical force, presumably caused by bounce of the vehicle and/or trailer.

That tongue weight is normally applied as a point load, on the ball. The BMW spec for the ball location is no more than 8" horizontally from the pin that the hitch drawbar is secured to the receiver with. There is a limit of 12" vertically from the top of the receiver to the base of the hitch ball.

Ignoring the vertical bending arm for a moment (because it comes into play on acceleration and braking only), the 600 lbs applied at 8" creates a certain bending moment, or twisting. I calculate it at 400 lbs ft for smooth roads, and 240 lbs ft for rough roads.

Your carrier would appear to apply a bending force of 350 lbs at a distance of 1.5 ft (assuming that the 350 is the weight of the carrier plus the bike). This is beyond the BMW safe design limit, which is based on a hitch that is arguably reinforced more than yours. You may decide to use up the BMW engineer's safety factor, or not.

Yes, I would expect to see your hitch receiver, and/or the rear unibody being twisted.

The pictures of the damaged X5 that I saw years ago where the damage involved a non-OEM hitch, also involved a luggage carrier inserted in the receiver. I don't know what the luggage weight was. I do know that I would be very cautious if I was you.

Does Draw-Tite publish a load limit for their receiver for carriers such as yours, apart from the tongue weight limit you mentioned? If they can point to test data and published figures, great. If they can't, or don't understand that a load applied farther out is not the same as a load applied close in, then you have some decisions to make.

Krunk Man · #27 07-01-2008, 07:14 PM

Quote:

Originally Posted by JCL

Does Draw-Tite publish a load limit for their receiver for carriers such as yours, apart from the tongue weight limit you mentioned? If they can point to test data and published figures, great. If they can't, or don't understand that a load applied farther out is not the same as a load applied close in, then you have some decisions to make.

On the actual receiver it says 6000pounds.
Everything you said makes logical sense, I might have to find a different way to carry the bike.