Just found this thread and am getting ready to tow very soon.

I have a couple of questions.

The discussion above talks about the toad diving below the MH in a panic stop. My question is: why would the toad run under the MH if the toad supplemental brakes are applied at the same time as the coach? My feeble mind thinks that the car being of lesser mass would stop faster than the MH and would not be able to dive under the MH since the toad would be stopping faster than the MH and since the toad would be actually pulling on the towbar.

Also, does the pivot ball on the Aventa II help to eliminate the problem with having the MH too high relate to the toad by providing an additional pivot point between the receiver hitch attachment and the toad? The pivot ball would seem to allow the towbar to "bend" in the middle and offset much of the height differences in either direction (high or low relative to the two vehicles).

Comments?

quote:

Originally posted by SteveR:
The discussion above talks about the toad diving below the MH in a panic stop. My question is: why would the toad run under the MH if the toad supplemental brakes are applied at the same time as the coach? My feeble mind thinks that the car being of lesser mass would stop faster than the MH and would not be able to dive under the MH since the toad would be stopping faster than the MH and since the toad would be actually pulling on the tow bar.

You are not feeble, you are asking a relavent question.

There would be no problem if the braking between the RV and the toad could be perfectly synchronized so that the toad brakes slightly more than the RV. This same principle would also help all automobiles....ideally the rear brakes will be slowing slightly harder than the front brakes. The reality is that we can't get it right on 4 wheeled cars, its nowhere near right on toad cars without anti-lock brakes.

Anti-lock brakes try to resolve this issue by relaxing the brake on any wheel that is spinning slower than the other wheels (in a nutshell this may not be right, but bear with me). Many tests have shown that professional drivers (whatever that means) can stop faster without anti-lock brakes, but the vast majority of us are better off with anti-lock brakes. Problem is, no one has implemented a coupled anti-lock brake system between the RV and the toad.

Two stopping scenarios are possible; 1) the toad is going to stop faster than the RV, 2) the toad is going to stop slower than the RV. Most auxiliary brake systems are going to fall into the 2) category. They will be set up for normal braking, so that the toad tires never smoke during a slow to middle braking maneuver. I doubt that anyone ever tests their toad braking system under a full lockup panic stop.

Personally, I would be perfectly happy to smoke the toad tires in a panic stop, but I have experienced ,nor heard of, any brake systems that will do this. I have, however, seen pictures of jack-knifed toads because the tow bar was tilted up from the RV to the toad.

Bottom line, given how little control we have over the relative braking characteristics between the RV and toad, it is wise to plan for the worst case. Hence the recommendation that the tow bar be almost level or slightly sloping down from the RV to the toad.

This message has been edited. Last edited by: alvinc,

Thanks for the reply. Futher measurements of center to center from the toad bracket tow bar attachment shafts to the raised receiver show a 5 inch increase above dead level with the RV side being the high end. I had to use a Blue Ox drop receiver in the inverted position to raise the RV receiver height to be above the toad height. Since it only comes in 2" length increments, I am opting to be a little high on the coach end vs spending another $100 for an other receiver that would drop the height by 2 inches.

The toad has a proportional braking system (SMI Silent Partner) which I will use in "Real Time" mode. This means that when the coach brakes come on and the coach is slowing down, the toad's brakes will come on. I have adjusted it were it is pretty sensitive on the early application of the toad brakes. Also, since the SMI creates a vacuum in the brake booster, the effort required to apply the toad brakes is very near "power brake" levels and should provide for much improved toad braking both in response time and in the amount of force applied.

I believe with all the above being considered I should be OK.

Here is another line of thought to tune up your brain.

The tow bar angle, in my mind, is less of an issue with a proper tow brake. By that I mean a good system with no built is surge suppressor or technology that determines if you are going down hill or stopping. These systems must think and in a panic, you nor your brake should think, it should just do it. Reading through the posts here it seems that the concern is that the car might try to climb in to the bed or some how sneak under it. IF, and I say IF you have a proper brake, then how could it?

Proper angle does reduce sway and tows a bit better. But those drop receivers add at least two pin connections which adds slop in the tow set up. Blue OX makes an extra part to help with this on one pin but rather than that, I still believe that a proper brake will eliminate the major part of this issue. Slop in the tow set up will add to sway in the tow which can add to more wear on the front tires and cupping. I do know a customer (a customer now but she used to have a competitors product) that folded a motorcycle carrier up into the back of her coach and then onto the hood of her truck. The angle was right but the stop was so fast that her brake could not keep up. At least that is what she told me. At any rate the brake failed her and she had 1000's of dollars of damage. A proper brake would have been much less than ½ of the repair.

Food for thought.

Pete

is this link the rite idea? rip
http://www.roadmasterinc.com/products/towbars/safe_zone.html

Your link does indeed show the correct tolerances for tow bars.

OK, how does all this pertain to a tow dolly? I would assume that the dolly plates, the area the toad front tires sit on, should be as level as possible. Also, I would assume that the tow bar should be as level as possible too. If one is out of whack, what should be done?

Does anyone know why Blue OX states that the tow bar must NOT angle up to the toad? The Roadmaster site shows a picture of the tow bar having a plus 3" to minus 4" of variance.

Does anyone know why Blue OX states that the tow bar must NOT angle up to the toad? The Roadmaster site shows a picture of the tow bar having a plus 3" to minus 4" of variance. We just bought a 08' Vue and it looks like the tow bar will be angled up to the car. I have not put the baseplate on yet but the installation instructions state what the height will be, and it looks like it will be higher than the coach hitch.

quote:

Originally posted by RLS:
Does anyone know why Blue OX states that the tow bar must NOT angle up to the toad?

Think of a pole vaulter. With the geometry mentioned, the tow bar would behave like the pole, and if the toad were generating less braking force than the tow vehicle, the toad would try to ride up and over the tow vehicle's receiver using the tow bar as the "pole" and the receiver ball as the box in which the pole vaulter plants the pole.

Rusty