New OEM Hitch Specs R a "Gotcha"!

[Riggodeaux]

Thanks, Jeff, very helpful; explained so even this caveman X5 jockey understands. This is exactly why xoutpost is such a great forum!

I just sent an email to CM [one of the major horse trailer manufacturers] inquiring about trailer gross and loaded hitch weight on a new bumper pull model [something none of the trailer manuf. seem to include in product literature] to make sure I don't buy too much trailer. I'll keep your thoughts in mind when/if I have to use a hitch cargo rack. As you say, probably better to use one of those aerodynamic roof top boxes, for anything beyond football tailgating come Fall .....

[JCL]

You're welcome.

Here is another data point for you.

The trailers being discussed generally don't use weight distribution equipment (aka load levelling bars). Some assume that they don't need them if they have air suspension, because air shocks can solve the headlights-pointing-at-the-sky problem, and make the vehicle appear level. That doesn't help the actual weight distribution, however, just the angle at which the vehicle sits.

Using the E53 dimensions, with the hitch ball 4" behind the rear bumper (I estimated this, but it is pretty close), 600 lbs of tongue weight applied at 8" from the receiver pin as per spec, doesn't add 600 lbs load to the rear axle, as some assume. It adds 838 lbs. And the front axle has a load reduction of 238 lbs. This is simple levers. You can hit the rear axle weight rating much sooner this way, and consequently lighten up the steering, inducing sway. For your horse trailer, one of the reasons they may not publish tongue weights is that it depends where you put the horse. It certainly matters when towing a track car, as you try to get 10% - 12% tongue weight.

Lots to keep in mind, and the above all gets worse when the load is applied more than 8" from the receiver pin, the limit that BMW specifies.

Jeff

[admranger]

Jeff,

Do you recommend anything like load leveling hitches on heavy loads (e.g., travel trailer with full 600 lbs on hitch and 6k total loaded mass)? Rear air springs.

I'm looking forward to towing a travel trailer around when I retire (in 7 years). So far I'm finding a number of trailers that meet my needs and the weight limits of the X5. I'd prefer the lightest trailer that I can afford, but there are limits...

[JCL]

Originally Posted by admranger

Jeff,

Do you recommend anything like load leveling hitches on heavy loads (e.g., travel trailer with full 600 lbs on hitch and 6k total loaded mass)? Rear air springs.

For a travel trailer, I would definitely recommend a weight distributing hitch, and likely sway control. A WDH doesn't work well with a boat trailer (due to the varying load) but it is well suited to a travel trailer.

You can even go one step further and use a pivot point projection hitch like a Hensley or Propride, as they put the swivel point close to the rear axle and are thus even more stable.