Hitch

[EOD Guy]

Can't speak for the aftermarket pieces..... my choice came down to the structural integrity of the rear in the event of a collision. If the vehicle were struck in the rear, the force that would be transferred from the receiver to the 1/8 inch steel plate that’s bolted to the uni-body cross member and would simply, IMO, buckle like a cheap suit. OEM hitch is a massive piece of steel that, IMO, in the same accident would transfer the load to the structural longitudinal areas of the uni-body that were designed to take them.

[drgeeforce]

I got some replies mentioning a change in the structural integrity by using the non-OEM hitches. I applaud all the "purists" who will remove their OEM hitches as not to distort the weight distribution of their X5s when not towing. As to all of you who leave their hitches on when not towing, that's your decision to be lazy and carry that extra weight, technically distorting the original design of the stock vehicle. There's even some who foolish enough to say it improves the structural integrity, without any evidence or testing. Some of you will say there's an implied safety issue having the non-OEM hitch. My reply, because my non-OEM hitch is EASILY uninstalled within minutes, it's a non-issue. I drive around daily without a hitch, whereas some of you "purists" leave the OEM hitch on because its too much a hassle to take off. 'Nuff said. It's dead.

[drgeeforce]

"...A warranty has absolutely nothing to do with how a product will perform. That is like saying that you will live longer if someone sells you life insurance. Remember when Chrysler went to 7 year powertrain warranties? Do you think they redesigned the engines that year?"So why did the Japanese cars have better warranties than American cars? their quality was much better than the Americans'."...The issue with hitches on E53's (that is the only model that I researched extensively) is not the hitch itself, it is the design, and by extension, the attachment method. Those 6 holes you reference are all drilled in the bodywork. There is no frame on an X5, it is a unibody design. In my opinion, it doesn't matter if you use a few or all of the holes in the bodywork, you are still attaching a trailer hitch to sheet metal. Early failures of the Drawtite hitch discovered this the hard way. The response was to add a fore-aft member to stop the 'twisting' of the bodywork when you do use those holes.&quot;There is no sheet metal in a Unibody design. see: http://books.google.com/books?id=mNIhYSCBfmUC&pg=PA318&lpg=PA318&dq=unibod y+ladder+frame&source=web&ots=EdURDDUZJC&sig=liZGK zNZADWL6Pyf5pr6fRj5CZ0&hl=en#PPA320,M1 </p>&quot;...The horizontal shock struts for the bumper are attached to longitudinal box sections, one per side. The OEM hitch replaces those struts with carrier braces that transfer the load into the strongest part of the unibody. It isn't a frame, but it is the nearest thing the X5 has.&quot;There is no 'strongest' part of the unibody, that's why it's called a unibody.The center 'pillar' of the non-OEM attaches to the subframe crossmember.Technically, a triangular configuration is achieved, whereas a box configuration is achieved with OEM.</p></p>

[EOD Guy]

What?

[JCL]

Originally Posted by drgeeforce

I got some replies mentioning a change in the structural integrity by using the non-OEM hitches. I applaud all the "purists" who will remove their OEM hitches as not to distort the weight distribution of their X5s when not towing. As to all of you who leave their hitches on when not towing, that's your decision to be lazy and carry that extra weight, technically distorting the original design of the stock vehicle. There's even some who foolish enough to say it improves the structural integrity, without any evidence or testing. Some of you will say there's an implied safety issue having the non-OEM hitch. My reply, because my non-OEM hitch is EASILY uninstalled within minutes, it's a non-issue. I drive around daily without a hitch, whereas some of you "purists" leave the OEM hitch on because its too much a hassle to take off. 'Nuff said. It's dead.

You missed the point entirely. The structural integrity while driving is exactly the same. The structural integrity in an accident, however, is not the same. Happy to have an engineering debate if you like, but I suspect it is dead, given your quote.

Just make sure you uninstall your hitch prior to any planned accidents. You will be fine.

[JCL]

Originally Posted by drgeeforce

There is no sheet metal in a Unibody design.

Yes there is, that is what the unibody is made out of.

Originally Posted by drgeeforce

There is no 'strongest' part of the unibody, that's why it's called a unibody.The center 'pillar' of the non-OEM attaches to the subframe crossmember.Technically, a triangular configuration is achieved, whereas a box configuration is achieved with OEM

That is just wrong. Push down on the centre of the roof. It deflects. Push down on the top of the A pillar. It doesn't deflect. Guess it must be stronger.

I understand that the fore-aft strut attaches to the subframe crossmember, from your description, but that doesn't change the fact that the hitch is hung on sheet steel.

Triangulation only matters if the apexes are solid. Also, the OEM mounts don't achieve a box section, rather, they attach to the box sections. They are the strong part.

Can I be one of the purists?

[drgeeforce]

Originally Posted by JCL

Yes there is, that is what the unibody is made out of.



That is just wrong. Push down on the centre of the roof. It deflects. Push down on the top of the A pillar. It doesn't deflect. Guess it must be stronger.

I understand that the fore-aft strut attaches to the subframe crossmember, from your description, but that doesn't change the fact that the hitch is hung on sheet steel.

Triangulation only matters if the apexes are solid. Also, the OEM mounts don't achieve a box section, rather, they attach to the box sections. They are the strong part.

Can I be one of the purists?

Unibodys are typically made of tubular steel in a hydroforming process exclusively, for MSLA and HSLA steels. [http://wardsautoworld.com/ar/auto_chassis_frames_new/]

No, there are no strong points on the rear vertical except for the D-pillar which is reinforced by wedges. [Body stiffness is further increased by wedges on the rear lid at medium height on the two D-pillars when closed. High strength(MSLA) and ultra-high-strength(HSLA) steel is used at the rear end of the new BMW X5 in order to achieve optimum stiffness and load resistance in a rear-end collision despite minimum use of material.
http://www.carbodydesign.com/archive/2006/08/12-new-bmw-x5/]

This is not where your OEM hitch attaches to. The 2-bolt flange attached to the 'ends' of the box section(aka unibody) is not attached to any subframe nor is there any reinforcement pillar. Only 2 bolts attach the mount/flange to the longitudinal box sections. The telescoping mounts replaces the rear bumper absorber and via a square tubular mild steel crossmember is saddle-welded to an offset receiver. Leaving the hitch on defeats the original BMW safety designed crumple zone where the monocoque chassis will deform inward in a crash-tested, controlled manner.
http://www.cars.com/go/crp/buyingGuides/Story.jsp?section=SUV&story=suvCrash2006&subject=s tories&referer=&year=2006
http://www.autoweb.com.au/cms/A_5567...wsarticle.html

Using your logic, the longitudinal box sections are sheet steel also.

BTW the six holed mount is the longitudinal box section crossmember(aka sheet steel). see the second picture http://www.x5world.com/articles/x5/m...tion-tips.html

Leaving the OEM hitch on alters the f/r weight distribution.

Lack of an impact absorber causes 100% of the collision forces directly onto the longitudinal box sections. If impact is off center, shearing forces will be predominant, again defeating the crumple zone.

I guess your opinions are just that, opinions.
Purists don't leave their hitches on.

[cmee330]

Well I do not know about all the aftermarket hitches but I do know after extensive research that none of them had a truly concealed hitch especially "hidden hitch" and a system hitch which was not sold ala cart, all had extra charges to complete the system. I have an X5 and a brand new X3 and me being a very picky BMW owner will not put on a product that takes away from the look of my BIMMER i.e. big square tube coming out the rear. Phantomhitchesdotcom provided me and my wife a complete tow system and excellent service.

Install was the same as after market brands(1.5hrs) but my hitch had a superior electronic cambus unit which is able to read my SAV advanced electrical system and it is HIDDEN (truly) from view when not in use. The price is more than the aftermarket but nearly half the cost of the OEM. Westfalia is the OEM brand which provides BMW its hitches but for the $1400-$1600 price tag they are truly smokin crack ! Check out the site(PHANTOMHITCHES.COM) if your looking for the IDEAL tow solution. You will not be disappointed, I was'nt.

Cheers

[JCL]

Originally Posted by cmee330

Install was the same as after market brands(1.5hrs)

That is because it appears to attach the same way the aftermarket hitches attach, to the sheetmetal at the back of the vehicle. If it actually includes longitudinal struts to replace the OE bumper shock absorbers, please advise because the site you listed doesn't show those in the photos.

Much safer to go OEM from a structural standpoint, but if the style of a hidden hitch is more important to you, then it does look clean.

[cmee330]

Well hello everyone I am new to this forum but man have I seen some comments on the lack of quality towing systems at a respectable price for our Bimmers. Well I have a 2006 X5 4.8 and my wife's has a 2007 M sport X3. I race bicycles and am now getting into track days with my Yamaha R1. I needed tow systems to tow my trailer and carry my bikes.

Every after market hitch had a hugh 2" square coming out my Bimmers rear not to mention that the wiring was not the most confident product to attach to the very complicated electronic system. And we all know how the OEM products are over priced and labor is outragous(4 hour install my a--). Well I was referred to a company that provided both my vehicles with OEM quality for nearly half the cost and this tow system came COMPLETE no ala cart or the need to purchase other items to complete the tow system.

Speaking of COMPLETE if you have a X5 with third row seating then you have no spare wheel. Well this company has a spare wheel carrier that works with the hitch system. Has anyone seen this product in the market place for the new E70 with third row seating?

What is really enjoyable and unique about my new hitch is that when I am not using it you cannot even tell or rather can't SEE I have a hitch at all!!!NO SQUARE TUBE AT THE REAR

So if anyone is looking for a great tow solution checkout this site phantomhitchesdotcom you will be impressed with this hitch.