Thanks for explaining that. Now I can see why it's not enough to move the car back on the trailer till the trailer doesn't put much weight on the tongue...that shifts too much mass to the rear causing swerving and unsteadiness.
Best is to move 50% of the mass forward, if not more, and use the weight distribution hitch to distribute the weight of the car back to the trailer. Do I have that right? Chris --- On Thu, 1/15/09, Fmiser <fmi...@gmail.com> wrote: > From: Fmiser <fmi...@gmail.com> > Subject: Re: [MBZ] TRAILER & block heater for Chris > To: "Mercedes Discussion List" <mercedes@okiebenz.com> > Date: Thursday, January 15, 2009, 2:38 PM > > Christopher wrote: > > > That sounds really nice. What is a weight distribution > hitch? > > To make a trailer dynamically stable, at least 10% of the > mass > needs to be in front of the trailer axles. 15% is better. > 50% > is best (it's then called a "semi-trailer" > -like the big > trucks use - rather than a "full trailer"). With > a majority of > the mass in front of the trailer axle, side-to-side > disturbances tend to be self-canceling. With more mass > behind > the axle, the oscillations self re-enforce. This is a > common > cause of upside-down trailers jack-knifed in the ditch. > > With a ordinary hitch, mass = weight. So a 2,000 lb (900 > kg) > trailer and a 4,400 lb (2,000 kg) car on it the gross > weight > of the trailer is 6,400 lb (2,900 kg). 15% of that is 960 > lb > (435 kg). That's how much weight will be on the very > back of > your van. It _will_ raise the front. > > The solution is "weight distributing". It is a > bulky hitch > assembly that's commonly seen on camper trailers. With > the aid > of one or two spring bars, tension is applied at the hitch > point lifting the back of the tow vehicle. The result is > some > of the weight is "distributed" to the trailer and > steer axles > - but the mass stays so the stability is not affected. > > Now that I have one, I can't see ever doing without it > - at > least when the trailer gross is more than 1/2 the truck > weight. > > -- Philip > > _______________________________________ > http://www.okiebenz.com > For new and used parts go to www.okiebenz.com > To search list archives http://www.okiebenz.com/archive/ > > To Unsubscribe or change delivery options go to: > http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com _______________________________________ http://www.okiebenz.com For new and used parts go to www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
