Aux brakes

[1carguy]

There is a very interesting article in the Prevost Prouds November 2007 newsletter that I received today.

The article can be found at:
www.wgr3.net/PrevostProuds/Newsletters/newsletter11-07.pdf

It was written by Bill Jensen, Service Manager, VIP Bus Shell Division of Prevost.

His comments are on page 6 of the newsletter and the information I am quoting is the last paragraph in his message.

He says: "For most of you who pull a car behind the motor home, the coach does not even know that the car is there. So braking and stopping distances remain as we have tested them! But for the people that tow larger trailers...."

Makes sense to me.

carguy

[Just Plain Jeff]

Bill Jensen, a 25-year Prevost veteran, attended POG IV at Branson and plans to be at the TN POG V rally. He presents on whatever topic folks are interested in hearing about and also hangs out with owners to answer any questions people may have.

Bill is a walking database of all things Prevost and is a great resource. If you can make POG V, you'll come away with a ton of knowledge. Bring along something to record all the information you'll get at a POG rally!

[Jon Wehrenberg]

I seriously doubt that a coach without a toad, and a coach with a toad will stop in the same distance. It defies the laws of physics,

If a coach weighs 45,000 lbs, and is towing 4,500 lbs. of something without auxiliary braking there will be a greater stopping distance than if the coach was not towing. As the weight being towed is reduced the stopping distance will approach that of the stopping distance of the coach alone and as it increases the distance required to stop will increase. Prevost would do us a great service by publishing actual stopping distances based on weights. Both the various weights of coaches without a toad, and at the same coach weights with the average toad weight without toad brakes.

If anybody wishes to demonstrate what I have just said without doing a full blown panic stop in their coach here is a simple way to prove my contention. Find a hill that you would ordinarily descend with the use of your engine retarder (Jake or transmission retarder) and begin the descent at a specific speed with the retarder at a specific setting. Note the speed at the top of the hill and the speed at some point along the hill or at the bottom. Repeat the descent with a toad attached, but with no toad braking. The coach will be going faster with the toad attached. The conclusion is that at a specific braking force the lighter vehicle (coach only) will slow, or build up less speed than the same coach with the addition of a toad.

[Joe Cannarozzi]

Jon I think that a 4500 lb toad is not in question. I would bet everyone would agree that it should have brakes. I can feel it back there and I'm sure others can too.

I believe it is the smaller toads that Bill is referring to. Stuff in the up to or around 3000lb category.

3000 lbs equates to 17 or 18 passengers in a charter situation. I would be very curious to here what a long time charter driver would say about braking distances and the difference with and without a load like that. I will guess that the answer would be JUST BARLEY but they do not carry all the weight of the conversion in addition to that as we do, pushing everything up closer to the load and braking limits.

I wonder if Prevo did the test with an empty shell or a loaded conversion?

Rodger what does a Mini-Cooper weigh?

I am sticking with my previous sentiments about comfortably pulling a SMALLER toad without brakes but if I were Bill or Prevo I think that suggestion would be different.

Another factor is the weight of the conversion alone. If you have one that the converter has built up against the Max. gross weight to start toad brakes will be more a factor and preferable.

[rfoster]

Joe: The Mini Cooper convertible weighs 2844 pounds.

[dalej]

Joe,

If I were you I wouldn't start my post with, I would bet, Jon likes that sort of line.

[Jon Wehrenberg]

As Roger's post shows, even a Mini is near that 3000 pound weight. I usually see folks towing SUVs such as Jeeps, Tahoes, Saturns, etc. Almost all of what I see is around 4500 or greater. I think a Wrangler, as small as it is approaches 3600 pounds. Any Hummer, Tahoe, Land Cruiser, Land Rover, full size pickup, Honda Pilot, etc. are at that weight of 4500 lbs. or greater.

Our coaches weight the equivalent of a charter coach fully loaded with people. We are all near gross vehicle weight, so when we have a toad without brakes pushing us we are likely going to feel the difference. Our brakes suck as it is. But the only way we will know the real truth is to do a braking test and measure the stopping distance.

[Petervs]

I agree with Jon, more weight means a longer stopping distance.

But it is all relative to the amount of weight. I specifically chose a VW Golf as a tow car because it only weighs 2500 pounds. Same as 300 gallons of water. OK, my fresh water tank only holds 200 gallons, but nobody thinks you need aux brakes on your water tank, or that you should drive with your water tank empty to reduce your stopping distance, right?

The 2500 pounds is a small enough percentage of the bus 45000 pounds that it does not NEED brakes. I am not saying my stopping distance is not longer, only that it is so little longer that it really does not matter. If you start towing over 3000 pounds ( in my opinion) you should have brakes on it.

The Smart is only 1600 pounds!

And my Cessna 172 is only 1400 pounds!

[Jon Wehrenberg]

I have no data to confirm this, but I think if we have to have extra weight to stop, having it in or on the coach will allow for a shorter stopping distance than if it is freewheeling behind the coach.

[lewpopp]

If you are pulling 2500 lbs behind the coach and it makes no difference in the stopping distance, than the extra 2 foot you travel into the rear end of the truck in front of you shouldn't bother you, huh?

Just lift your feet up and lean back if this should happen. Tell your co-pilot to do the same.

[Jim_Scoggins]

As long as we take a reasonable man approach to this I can think of nothing whereby we would be better off weighing more. I usually carry about one half tank of water and after the initial burn down, tend to run between 1/4 -3/4 tank of fuel. Bt the same token, I bet most of us don't run around with full waste tanks. I have slowly been reducing the amount of tools and spare parts I carry. If I could get Dragon Lady to reduce the stuff she carries I would be all set. (I weighed it before and after:1500 lbs delta.)

As a reasonable man, I as of yet see no reason to reduce the amount of the Gin reserve. Malaria must be fought when and where ever you find it.

Come to think of it, I probably need to lose 100lb to get to fighting weight and thus help out bus max gross.

We motorcylists are usually wondering about the best way to improve performance. Nothing dramatically increases performance as much as a lighter rider: Greater percentage of total weight.