Jerkiness while towing

[whemme]

David Potter,

My intent is not to start an argument here but I need to say that the laws of physics still apply no matter who manufactures a tow bar system and no matter what kind of offset was designed into their tow bar.

If the base plate attach points are 7" lower than the receiver ball on the back of your motorhome, then during a really hard stop, this 7" drop will result in a very significant portion of the deceleration force being transferred as a downforce on the baseplate attach points which may result in damage to the front suspension of your toad and/or the baseplate itself.

The following is quoted from the tech topic Towing Physics 101 on Blue Ox's website as follows:

Blue Ox's recommendation is that the receiver hitch of the motorhome should never be more than 4 inches higher than the baseplate attachment points. Four inches or less keeps the tow bar level with the ground or slightly angled up towards the coach from the car. The tow bar should never be angled "up" towards the car from the coach. If an extension is added for say a bike rack it is even more imperative the tow bar not be at a severe angle. Not only does it increase the leverage, but each connection adds more slack in the whole setup. It's all geometry and physics. Please, no groans, I know you enjoyed those classes! The farther back you move the pivot point of the tow bar from the center of gravity of the coach, the more vertical movement you get and the more leverage is applied to the receiver hitch, tow bar and the baseplate. See, that wasn't so bad!

You can read the complete document at their website link below:

http://www.blueox.us/instruction/towingphysics101.htm

[BornFree_n_Now]

Another issue which may give you a jerky feeling while towing and actually cause greater wear and tear on your equipment in the process is the metal to metal nature of most connection apparatus. We had a cushioned bar constructed by the folks at Convert-A-Ball for our Roadmaster tow assembly (see http://www.2kstore.com/cam/cbl1.htm to see a representation of a cushioned ball mount).

I would not tow anything of weight without one of these cushioned mounts (also had them make a “correct lengthâ€

[Roger H]

I'm being nosy here, Larry. What did the custom ball mount cost you? I had a standard 2" solid steel one fabricated at a machine shop, and assembled by a welder, and it cost me about a hundred bucks. This cushioned thingy looks like just the ticket!

Roger

[Dave&JanPotter]

Bill Hemme:
I understand your point about forces on the tow car but there are other considerations. In the case of the Acclaim towbar, it must stay on the ball coupler during a stop too. My intent wasn't to argue the laws of physics, but to make the point that rather than assuming that all tow bars must be mounted level, one should check the manufacturers installation instructions for the specific towbar. If you check page 4 of the below link to the instruction book from Blue OX you will see the background for my statement in the original post. Thanks for all you do for the club.
http://www.blueox.us/Towbars/bx4330.pdf

[BornFree_n_Now]

Roger,

I believe that EACH the normal tow bar and the modification to the Roadmaster Falcon 6000 lbs. rated tow bar were $60, plus shipping. Very nice folks, who offered exceptional service and fast turnaround ~~ I simply took the shank off of our Falcon, and shipped it to them for conversion to their cushioned unit. They performed the task, and returned the finished product to me within a week, from across the country. These are not solid construction, but ¼â€

[bill crommett]

Don: If the preceding information does not solve your problem you may consider a problem that occurs with towing a travel trailer. In some instances the wheelbase of the towing vehicle get synchronized with the wheelbase of the trailer so that on an older piece of pavement the the two vehicle are are the crest of the wave and subsequently are both at the trough of the wave Maybe it is the other way around so that the two vehicles are NOT on the crest or the trough at the same time.Needless to say, the solution to this type of problem is expensive.