Interesting comment on Facebook about Model-A Brakes

[BRENT in 10-uh-C]

I often just shake my head at some comments I read that are posted on Facebook about Model-As, ....but this one piqued my interest for sure.

Posted by Dennis Harvey;
I've professionally restored Model A's since 1966. We've used a backing plate mounted on a Dynamometer and measured torque of std. brakes and modified brakes using brake floaters. We found an 11.649% increase in the force of brake shoes against the drum on the backing plate using floaters. Original brakes are ok but modified brakes are better. A fact not opinion.

Thoughts/comments regarding this increased force??

[pooch]

You state this as a comment.

He states it as a fact with real time tests.

[Pete / MA]

I belive the self actuating effect of drum brakes requires that the shoes must be allowed to "float" and not pivot on an anchored point. Not sure about the percentage results from his test.

[Rex_A_Lott]

I'd be curious of the total torque number they measured. 11% could be a big or a small number.
How many times was the test run, and what is the accuracy of the test?
Interesting though that somebody finally did what seems to be a decent actual comparison test, and shared the results.

[larrys40]

Brent,
I would say that they had to obviously change the components which changed the brake adjustment and could effect their results by at least that percentage.

Even one click of the brake adjusting wedge can make a difference. In my opinion the original system does well when rebuilt properly. I've taken off more brake floaters that were causing issues than solved them.

Everyone has their opinion just like they do... I can't see going through all the motions to try and prove that.... not sure what the actual point was. Maybe he is selling brake floaters?

Just my 2 cents worth..

[MikeK]

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I'm OK with the increased force, likely do to self-actuation like Bendix, but the last statement "Original brakes are ok but modified brakes are better. A fact not opinion." is a problem. Here we have a conclusion that either overrides the raw data and projects a real driving outcome (not tested) or it is not explained well. Does a car stop better if you lock up the wheels with juice, floaters, 11.6% harder pressure on a Lockheed pedal, or by jamming a big crowbar through the spokes?

Perhaps the writer simply meant having 11.6% reduced pedal pressure is better for normal driving? This is an inferred conclusion, not a tested fact.

I've read thousands of real, and published engineering and scientific studies over the years. A statement of inference such as the one in discussion would never pass peer review for publication.

Putting the final touches on my Gilmore seminar. You'll find out Saturday who Fishleigh was, what happened at Ford engineering, what headlamps were supposed to go on the A but didn't, and many details previously unknown. You'll also see the results of application of science and math, not wive's tails. Then you can form your own conclusions and inferences based on what is presented. Hope to see you all there!

Mike Keating

[Kevin in NJ]

Which group did it posted on?

Here is where science has a set of rules that tend to not be understood by the public. His statements are nice, but useless without full details.
We need to have enough information to be able to repeat the tests. What machines did he use, how did he do the test set up and such.
MikeK nailed the rest of the problems with his statement.

So while it sounds great that he ran a test, it is still useless information as it is presented. It is only as good as opinion.

Keep in mind I am NOT saying what he did is wrong. I am saying that as a scientist I do not have enough information to believe what he has stated as being fact and meaningful.

[Tom Wesenberg]

The fact that some of the brake shoe retracting springs are removed would mean the pedal pressure is less.

Not that removing retracting springs is a good thing to do.

[BlueSunoco]

Originally Posted by larrys40

In my opinion the original system does well when rebuilt properly. I've taken off more brake floaters that were causing issues than solved them.

I'm no expert on Model A brakes, but people who are have consistently told me that the original brake system restored to original, in every detail, WAS a good system. I've always been told that brake floaters were a bandaid repair and wasn't addressing the real problem which was, brakes not properly restored. I have to agree with Larry.

[Skibb]

Originally Posted by MikeK

I'm OK with the increased force, likely do to self-actuation like Bendix, but the last statement "Original brakes are ok but modified brakes are better. A fact not opinion." is a problem. Here we have a conclusion that either overrides the raw data and projects a real driving outcome (not tested) or it is not explained well. Does a car stop better if you lock up the wheels with juice, floaters, 11.6% harder pressure on a Lockheed pedal, or by jamming a big crowbar through the spokes?

Perhaps the writer simply meant having 11.6% reduced pedal pressure is better for normal driving? This is an inferred conclusion, not a tested fact.

I've read thousands of real, and published engineering and scientific studies over the years. A statement of inference such as the one in discussion would never pass peer review for publication.

Putting the final touches on my Gilmore seminar. You'll find out Saturday who Fishleigh was, what happened at Ford engineering, what headlamps were supposed to go on the A but didn't, and many details previously unknown. You'll also see the results of application of science and math, not wive's tails. Then you can form your own conclusions and inferences based on what is presented. Hope to see you all there!

Mike Keating

MikesK, would there be a chance there will be a video/CD/YouTube of your your seminar available to those fascinated by Model A life.

[BRENT in 10-uh-C]

Well, I have studied/installed the F/H Ted's units also, ...and I sure did not see how the F/H could increase the force (--or pressure). Even with the brake spring removed, it really does not increase the force, -but moreso just reduces the effort required to depress the brake pedal. I agree with Tom that not removing that spring is a good thing. I have heard of shoes dragging on the drums due to this. It is also worth a thought to ponder if this was such a good idea, why didn't Ford actually save the money and remove that spring also?

Another thought was even if his findings are indeed legitimate, by having the 11+% additional brake pressure, what does this gain you? In the situation of a worn stamped steel brake drum, that additional force is limited by how much the drum expands. In other words, once you have reached the extended length of the mechanical mechanisms, you are done anyway, -so having 11% more pressure is of no value in my mind if the system is already bottomed out. With cast iron drums, I can repeatedly lock-up the drums with a stock braking system, so that tells me that I can exert plenty enough braking force without the F/H Ted kit, ...so I am unsure exactly what 11% more force is going to do to assist in braking.

Mike, I like your analogies, ...especially the one with the crowbar & spokes!!

[H. L. Chauvin]

Human opinions on Scientific Test Reports, Studies, & Surveys are "always" most interesting.

If Study A ....... conducted by professionals ...... indicates that red wine increases one's life span .......... the red wine drinkers love it, and will agree.

If another professional Study B indicates that red wine shortens one's life span ...... the red wine drinkers cling to Study A and reject Study B.

Are the opinions after Study A ............. or the opinions after Study B 100% correct?

Maybe checking shopping baskets exiting stores where wine is sold might give one a clue on how the human mind works!

One (1) Opinion on the Moral of these Two (2) Studies:

Stay calm ........ say nothing ...........and before exiting the store .......... wrap all twelve (12) your red wine bottles in a brown paper bag so nobody will think you are ignorant.

[BRENT in 10-uh-C]

Originally Posted by H. L. Chauvin

Human opinions on Scientific Test Reports, Studies, & Surveys are "always" most interesting.

If Study A ....... conducted by professionals ...... indicates that red wine increases one's life span .......... the red wine drinkers love it, and will agree.

If another professional Study B indicates that red wine shortens one's life span ...... the red wine drinkers cling to Study A and reject Study B.

Are the opinions after Study A ............. or the opinions after Study B 100% correct?

Maybe checking shopping baskets exiting stores where wine is sold might give one a clue on how the human mind works!

One (1) Opinion on the Moral of these Two (2) Studies:

Stay calm ........ say nothing ...........and before exiting the store .......... wrap all twelve (12) your red wine bottles in a brown paper bag so nobody will think you are ignorant.

EXCELLENT!! Cards well played Sir!! Yep, ...very well played!!!

[700rpm]

Originally Posted by skibb

mikesk, would there be a chance there will be a video/cd/youtube of your your seminar available to those fascinated by model a life.

x2.

[Vic in E-TN]

This is interesting. I do not have the study available describing how the tests were performed. I have a few questions 1. How were the force or torque figures arrived at? Was the wheel turning or static (breakaway forces vs. dynamic forces)?
Designing a test to prove or disprove something requires some thought.

I have two types of front floaters on my cars. Years ago I put on the pants leg type and was pleased at the time. I have not driven that car in 12 years - It spent 6 years in the paint shop. I have been using the $25 type that the vendors now sell on a few cars that I purchased since then. I think that they theoretically should help because they use a primary/secondary shoe system. On one car I even cut a few inches off the beginning and end the lining to approximate the "modern" drum system. They all seem to work well.

In any case one should not use a result to 3 decimal places unless there are enough tests to prove that. There should then be a statistical figure attached to that result or it should have been stated as "approximately 10-13 percent better".

Vic

[bbrocksr]

Originally Posted by BRENT in 10-uh-C

I often just shake my head at some comments I read that are posted on Facebook about Model-As, ....but this one piqued my interest for sure.

Posted by Dennis Harvey;
I've professionally restored Model A's since 1966. We've used a backing plate mounted on a Dynamometer and measured torque of std. brakes and modified brakes using brake floaters. We found an 11.649% increase in the force of brake shoes against the drum on the backing plate using floaters. Original brakes are ok but modified brakes are better. A fact not opinion.

Thoughts/comments regarding this increased force??

Floaters increased the force of the shoes against the drum resulting in more torque applied to the backing plate mounted to the Dyno so it can be measured.
Sounds like this guy made an effort to prove a theory.
Bill

[Bruce_MO]

Wouldn't a more "real world" test be to assess road performance... stopping distance, control/stability, pedal pressure rquired for lock-up... between stock and floaters on the same car? Long before anti-lock brakes, Motor Trend and guys like Tom McCahill were comparing stopping distances and "performance" of the brake systems with some sort of standard approach. It would be neat if someone took a well-restored car and did 5-10 runs, and then installed floaters and repeated the process. With a comprehensive head-to-head comparison, and some "data" (three decimal places not necessary!), it would pretty neat. I've seen old McCahill articles that show car A stopping straight and car B fishtailing into cones, etc. I just think it would be neat to come up with a less subjective approach. Like a few of the folks on this thread, I think the stock system is sound and too many floaters are band-aids on crappy systems, but the theory of floaters should give them the advantage. If I was 70 years old (getting there) and I wanted excellent braking at less pedal pressure, I'd like to know if it's feasible. People are investing in easier steering... same kind of idea in my head.

[CarlG]

Didn't I see somewhere that someone had a Power Assist unit that was made for Standard Model A mechanical brakes??

[goodoldvic]

My stock configured brakes with steel drums work very good for me. I'm satisfied with the performance of them given my driving and the local traffic. I did drive out of my comfort zone traffic area ( lotsa traffic) and still are of the same opinion.

[john charlton]

I have found albeit rarely that someone will pull out from a "T" junction in front of me . I suppose because they see an old car approaching they missjudge the closing speed . In an emergency braking situation I can lock up all four wheels for sure ,this I have done several times once twice in one day !!! . I have correctly adjusted stock brakes with the late 31 spoked cast iron drums and regular rear drums. There is a servo effect as the front end is very flexible and under heavy braking the front axle rolls forward slightly and as the brake levers are on the top of the backing plate it does add braking force for sure .Correct adjustment of an unworn braking system will be as good as a hydraulic system any day IMHO . The rears have the reverse effect as the levers are on the bottom but that is a more rigid setup .

John in very heavy rain flash floods forecast Suffolk County England .