Braking situations that fill your Underpants

[Steve L.]

I think everyone's agreeing with each other in that the Prodigy doesn't apply the trailer brakes until you touch the brake pedal. Then it can be set to boost the trailer braking compared to what the tow vehicle is doing.

I expect, however, that if the brake controller people wanted to add a "clairvoyant" setting, they could sense any deceleration (lifting off the gas suddenly, or going down hill) and activate the trailer brakes before you actually touched the brake pedal. Sounds like a really bad idea to me, but then I'm often surprised at what some people think is a good idea

[Carol H]

Originally Posted by floyd

The Prodigy has a boost setting which applies additional power at the beginning of the braking cycle. In this mode the Prodigy momentarily anticipates and applies extra braking ahead of the tow vehicle, then instantly reverts back to pendulum(proportional) operation.
So actually it should and does happen on boost mode.

Yes the controller does apply extra brake power to the trailer when on boost but you still need to press the car brake first to trigger the trailer brakes. So I stand by my original comment that the brakes can not come on ahead of the cars and the poster must have their controller on a pretty high setting. Impossible to have the brakes of the trailer come on before the cars unless they are using the lever only on the controller. Few folks with 16' fiberglass trailers need/use the boost function on their controllers due to the size of the brakes on a 16' trailer vs a 13'. I know if I was to but my controller on just level 1 boost the 16' would be jumping like a bunny rabbit. If the ops trailer isnt bunny hopping on boost then its a good bet at least to me, that the trailer is not only having to stop its own weight but some of the weight of the tow as well, due to the very light curb weight of the tow. Not a situation I would feel comfortable with towing in a high mountain pass

[floyd]

Originally Posted by 343625

I think everyone's agreeing with each other in that the Prodigy doesn't apply the trailer brakes until you touch the brake pedal. Then it can be set to boost the trailer braking compared to what the tow vehicle is doing.

I expect, however, that if the brake controller people wanted to add a "clairvoyant" setting, they could sense any deceleration (lifting off the gas suddenly, or going down hill) and activate the trailer brakes before you actually touched the brake pedal. Sounds like a really bad idea to me, but then I'm often surprised at what some people think is a good idea

Steve L.;
If your comment was meant to be in response to mine, it's a non sequitur.
The point being that the Prodigy is not proportional at the beginning of the braking cycle when using the boost mode.
Carol H;
The minimum boost, if I recall, is 13%,and it is anticipatory.(essentially braking ahead of the car).
Your original comment was..."something doesn't sound right if the trailer is braking ahead of the car. Shouldn't/cant happen." Your second assertion was...
"the brakes can not come on ahead of the cars"(sic)
Also the Prodigy is activated with the brake light switch and since no real braking occurs at the top of the pedal, it calls into question the technical accuracy of your second point, as would ABS.
Still, at some level, you are not incorrect.

[Borden]

It says in the instructions that it should barely feel tailer brakes at the start of braking cycle, after that it seems to be proportional. Understanding is this is to prevent a pushing of vehicle at start of braking cycle; yes it only activates with pressing of pedal.

[Carol H]

Originally Posted by floyd

Also the Prodigy is activated with the brake light switch and since no real braking occurs at the top of the pedal, it calls into question the technical accuracy of your second point, as would ABS.
Still, at some level, you are not incorrect.

LOL dont know Floyd I guess due to the fact I tend to like to keep the brakes on the car and the trailer in good shape - ie probable replace both sooner than really needed I would have to be very careful not to make much if any contact with the cars brake pedal not to get any braking action from it.
Happy to see though that it appears we at least agree on the laws of physics

[Steve L.]

Originally Posted by floyd

Steve L.;
If your comment was meant to be in response to mine, it's a non sequitur.
...

My response was not directed at anyone specifically but to, hopefully, diffuse what I thought what becoming a contentious discussion by recognizing that you were each saying essentially the same thing.

I get the sense that you’re bound and determined to pick a fight with someone, you just don’t know with whom specifically. In my view you make a distinction without a difference when claiming the trailer brake is leading the tow vehicle brakes because although one is pressing the brake, the brake is not effective over the first bit of travel. Yes… but… so what? You are still pressing the tow vehicle pedal before the trailer acts.

I didn’t read anyone as saying there wasn’t more trailer boost at the start (assuming the boost feature is activated) and thereafter it was proportional to deceleration. Maybe it’s all about what “leading” means.

But, hey, I’m no longer a moderator and should let nits be picked without comment.

[Francesca Knowles]

Hmmmm...

Does the present side trip down who-cares-lane qualify for some as a
"Braking situation that fills your underpants", in the sense of the O.P.'s truly novel threadtitle?

Francesca

[David Tilston]

On my last trip the acceleration feature on the Prodigy controller caused the trailer to lock up on a steep down hill decent. I had noticed that the trailer was grabbing more then the tow vehicle up to that point. I kinda liked having more drag in the back so that the trailer stayed behind me. The additional acceleration of the down hill caused the brake controller to brake so hard that the trailer locked up. A quick adjustment to the gain fixed the problem.

[Carol H]

Originally Posted by Francesca Knowles

Hmmmm...

Does the present side trip down who-cares-lane qualify for some as a
"Braking situation that fills your underpants", in the sense of the O.P.'s truly novel threadtitle?

Francesca

Nope but the set up being discussed sure might make for one someday in the not to distant future

[Jim Bennett]

Originally Posted by Carol H

Nope but the set up being discussed sure might make for one someday in the not to distant future

For sure. Sometimes these side tracked conversations bear more information that the original request.

I can set the trailer brakes to apply before the car ones if I wish, but I never do. One idea behind that is they kind of act like a parachute, pulling back on the tow, thus minimizing the chance of jackknifing. If you were towing with a much heavier setup, it would be more useful.

[Francesca Knowles]

Originally Posted by Jim Bennett

I can set the trailer brakes to apply before the car ones if I wish,

There's a controller setting that will accomplish this?

Francesca

[floyd]

Originally Posted by Steve L.

My response was not directed at anyone specifically but to, hopefully, diffuse what I thought what becoming a contentious discussion by recognizing that you were each saying essentially the same thing.

I get the sense that you’re bound and determined to pick a fight with someone, you just don’t know with whom specifically. In my view you make a distinction without a difference when claiming the trailer brake is leading the tow vehicle brakes because although one is pressing the brake, the brake is not effective over the first bit of travel. Yes… but… so what? You are still pressing the tow vehicle pedal before the trailer acts.

I didn’t read anyone as saying there wasn’t more trailer boost at the start (assuming the boost feature is activated) and thereafter it was proportional to deceleration. Maybe it’s all about what “leading” means.

But, hey, I’m no longer a moderator and should let nits be picked without comment.

As Paul Simon wrote..." Still a man hears what he wants to hear and disregards the rest". Your "sense that I was "determined to pick a fight with someone" was completely without foundation.
If I were to do so... I am certainly capable of knowing with whom.
I was in fact only responding to the statement that with the Prodigy "the trailer is braking ahead of the car. Shouldn't/cant happen."
A statement which is simply contrary to the design of the Prodigy, which can and does.
Notice I had said..."at the beginning of the braking cycle."
I said nothing provocative at all. You on the other hand have been clearly provocative in the above statement. I considered taking this response offline to a private message, but thought it obvious(not by clairvoyance)that you wanted it to be public.
However, I still have no wish to "pick a fight with someone", eventhough it it has become abundantly clear with whom it would be appropriate to do so!
I apologize if I have been unable to comment on this subject at a level comensurate with your understanding, but I can assure you I have done so without malice of any kind.

It is my hope that even with the confusion, this discussion has lead(or will lead) to a better understanding of this most popular of brake controls, which was the sole intent of my involvement.

[Carol H]

Originally Posted by Francesca Knowles

There's a controller setting that will accomplish this?

Francesca

Pulling the lever on the controller is one way.

Jim, is correct there are often bits of useful information that can be obtained as a result of the side line conversations that take place.

In this situation due to some being fairly new to towing they may not be aware that few of us pulling 16' fiberglass trailers right up to much bigger heavier 19's that I know of, need or use the boost function on their controllers. We don't use the booster as it will in most cases result in the trailer doing bunny hops. The fact we have a poster who feels they needs to use the booster and his unit doesn't bunny hop suggests the trailer brakes are stopping more than just the trailer. So the question is what would happen if a set up like thats trailer brakes were to fail, which does happen (happened to me on a trip last year) and they were traveling down a steep grade? The story Frederick tells of traveling down hill with no trailer brakes is a real scare one that chilled me just reading it. In his case he was pulling the trailer with a tow that has a curb weight much greater than his trailers weight - making it a little bit harder for the trailer to push the car. Imagine if that same situation was to happen while pulling a trailer that weighs as much if not more than the curb weight of the tow? Do you think it would ever stop? Scarey? Something more for people to think about when choosing a tow vehicle.

In so far as how to apply the trailer brakes without applying them to the tow goes. Thats again something that someone new to towing may not know how to do or realize under what situation they may need to do it. If one looks at the tow set up that triggered the side line topic any one who has been towing for more than a few months and faced various weather and terrain situations can problem come up with more than a few situations where the poster is going to want/need to know how to apply only the trailer brakes. One I can think of right of the top of my head is if they find themselves towing out in the desert and the winds come up. What do you think would happen if a good side wind hits a trailer that weighs as much or more than its tow? Its a good bet due to the light tow not being able to hold the trailer firmly in place, that the trailer would not only start to sway but its also a petty good bet it would wag the tail and spin the tow like a top. Just last year I watched a big semi with trailer in tow end up sideways in front of me on a southern desert highway due to side winds.

I don't think anyone here really wants to have a story to tell on this threads topic or have someone else put themselves in a situation that they may have one in the future to tell if by sharing our collective knowledge it can be avoided.

[Francesca Knowles]

Originally Posted by Carol H

Pulling the lever on the controller is one way.

I know how to use the manual control knob on trailer brakes- my question was about Jim's assertion below, re. "setup".

Originally Posted by Jim Bennett

I can set the trailer brakes to apply before the car ones if I wish, .

Originally Posted by Francesca Knowles

There's a controller setting that will accomplish this?

Francesca

[Jim Bennett]

Originally Posted by Francesca Knowles

There's a controller setting that will accomplish this?

Francesca

Okay, I started to type out what I though the settings were from memory, checked to find a manual online, and just copied this instead. WAY more accurate than what my brain cells could produce.

In reality I guess that the trailer brakes are not ahead of the tow, but their strength of application is ahead of the tows, which effectively does more or less the same thing.

I hope this helps.

-----------------------------------------------------------------------------------

Boost Setting

The boost button was designed to allow a more aggressive
setting for your trailer brakes and is available in three
levels - B1, B2, B3. Each incremental boost setting
increases the sensitivity of the P3’s inertial sensor,
enhancing the participation of the trailer brakes during a
braking event.
Truck/Trailer B1 icons on the screen indicate Boost On.
For example: With the boost off, during a braking event,
the power to the brakes starts out at zero and increases
with deceleration. With the boost on level 1,
B1, during a braking event, the power automatically
starts out at approximately 13% of the power setting and
increases with deceleration. With the boost on level 2,
B2, or with the boost on level 3, B3, during a braking
event, the power automatically starts out at approximately
25% of the power setting and increases with deceleration.

Some cases where you might want to use the boost button:
• You like the trailer braking to ‘LEAD’ the tow
vehicle’s braking
• Towing a full vs. empty trailer
• Degraded brake performance (most electric brakes
require manual adjustment - see Appendix A or a
dealer for adjustment or repair)

[Francesca Knowles]

Originally Posted by Jim Bennett

Okay, I started to type out what I though the settings were from memory, checked to find a manual online, and just copied this instead. WAY more accurate than what my brain cells could produce.

In reality I guess that the trailer brakes are not ahead of the tow, but their strength of application is ahead of the tows, which effectively does more or less the same thing.

I hope this helps.

-----------------------------------------------------------------------------------

Boost Setting

The boost button was designed to allow a more aggressive
setting for your trailer brakes and is available in three
levels - B1, B2, B3. Each incremental boost setting
increases the sensitivity of the P3’s inertial sensor,
enhancing the participation of the trailer brakes during a
braking event.
Truck/Trailer B1 icons on the screen indicate Boost On.
For example: With the boost off, during a braking event,
the power to the brakes starts out at zero and increases
with deceleration. With the boost on level 1,
B1, during a braking event, the power automatically
starts out at approximately 13% of the power setting and
increases with deceleration. With the boost on level 2,
B2, or with the boost on level 3, B3, during a braking
event, the power automatically starts out at approximately
25% of the power setting and increases with deceleration.

Some cases where you might want to use the boost button:
• You like the trailer braking to ‘LEAD’ the tow
vehicle’s braking
• Towing a full vs. empty trailer
• Degraded brake performance (most electric brakes
require manual adjustment - see Appendix A or a
dealer for adjustment or repair)

.....
.............

So...is it fair to assume that you don't understand any of that marketing who-shot-John any better than I do?

Francesca, born skeptic

[Jim Bennett]

Originally Posted by Francesca Knowles

.....
.............

So...is it fair to assume that you don't understand any of that marketing who-shot-John any better than I do?

Francesca, born skeptic

I do know the answer to that, but I will only tell it to a tabloid for huge amounts of money.

And, nobody is a bigger skeptic than me. I'd be wanting proof for everything that remotely sounds strange to me.

[Francesca Knowles]

Originally Posted by Jim Bennett

I do know the answer to that, but I will only tell it to a tabloid for huge amounts of money.

..........
Well sallied, Matey!

I think we understand each other...

Francesca

[gmw photos]

Originally Posted by Carol H

LOL dont know Floyd I guess due to the fact I tend to like to keep the brakes on the car and the trailer in good shape - ie probable replace both sooner than really needed I would have to be very careful not to make much if any contact with the cars brake pedal not to get any braking action from it.
Happy to see though that it appears we at least agree on the laws of physics

I would add that it's entirely possible you are both right ( or wrong ) depending on the car and "how" the brake light circuit is activated.
For instance, on my Nissan Frontier, the brake lights ( and therefore the prodigy ) are activated by a mechanical switch, which turns power on in the very first part of the pedal travel, which is before the hydraulic master cylinder is actually building pressure in the lines to the wheel cylinders. So at least in my case, a very light brush of the trucks brake pedal is applying power to the trailer brakes, but not the tow vehicle.
But on some car designs ( older Fords were this way, and some may still be ? ) the brake lights are turned on by a switch that is literally activated by line pressure in the hydraulic line to the brakes. In that case, you would already be sending pressure to the TV brakes, and simultaneously beginning the power curve to the trailer brakes.

As to whether the boost settings "work as advertised" or are just a marketing ploy, my experience with the P2 is that the boost settings do in fact have differing levels of feel in the way the trailer brakes function. I have no way to absolutely quantify their claimed "percentages of initial power output", but I will say again, the settings work, and in my case, just as the instructions imply, B2 seems to work well for my truck/trailer combination.

Bottom line is it's a good brake controller that is certainly superior to old fashioned devices such as "surge brakes". And I too agree that users of these controllers should be proficient at and practice regularly using the "johnson bar" ( the little manual lever ).

As for the OP's original question and the title of the thread topic.....I pulled into the lane one one time at the barn with the flatdeck fully loaded with probably 10,000 to 12,000 pounds of hay....and had the brakes on the truck decide to fail ! Was glad for two things: 1. I was home, and only doing about 10 mph, and 2. Was glad the trailer brakes were working !

[glamourpets]

As I watch people's posting I notice that none of the "underpants filling" experiences include jackknifing if the trailer brakes are functioning normally.

Would it be reasonable to say that on rigs the size of those owned here, jackknifing is primarily caused by inadequate trailer brakes? Perhaps they don't work, or perhaps they don't exist in the first place. Thoughts?

Derek

PS. I realize any idiot can prove a rule of thumb wrong. For the sake of conversation, we are not talking about "true idiots" here. We are talking about "normal people" caught in a tight spot.