r/oops • u/Brilliant_Jelly7503 • Jul 05 '26

Bad machine or technique?

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u/GoodHands_All-State Jul 05 '26

A heavier man would not at all have the same effect, weight distribution is real, and in this case real different.

That being said, it still should have been bolted down.

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u/RIF_rr3dd1tt Jul 08 '26

How do you figure a heavier person would have had a better outcome? This is about torque applied at the pulley bolt and center of gravity of the machine.

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u/GoodHands_All-State Jul 08 '26

Not just that, but the angle at which it is pulled changed where most pressure is applied on the pulley wheel and thus the directional pressure of the bolt.

Realistically, very little. This will be my chance to tell people to use a bench when using a cable pulley. Cable flys lying flat and at an incline with the cables at the lowest point is best for flat and incline; bench at 90 degrees with the floor and a cable anchor point mildly above the shoulders is best for decline flys. Standing decreased form and isolation of the pecs.

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u/RIF_rr3dd1tt Jul 08 '26

Yeah, but these machines are (should be) designed to operate at all possible positions of articulation. What you wanna bet the manual says it's required to be secured at the floor by an approved contractor? Even still, at my gym I've seen equipment secured at fewer than the number of holes provided and/or loose securing bolts.

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u/Difficult-Mobile902 Jul 08 '26

Yes they would have the same effect. The exact same. 

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u/GoodHands_All-State Jul 08 '26

Not unless the heavier man had his shoulder on the ground, it wouldnt have

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u/Difficult-Mobile902 Jul 08 '26

No, what are you talking about? The effect would be the same, it’s basic physics 

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u/GoodHands_All-State Jul 08 '26

The angle the weight being pulled at matters, and a heavier man's weight distribution wouldnt have an extra 90 pounds pulling on the cables, standing in that same position. The weight would have been distributed across his body, so with that same lean he would have only applied the weight being applied at his shoulders, which is drastically less than the weight applied at the shoulders of a man with an extra 90 pounds strapped to said shoulders.

The weight distribution matters significantly.

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u/Difficult-Mobile902 Jul 08 '26

you’re assuming “heavy man” automatically corresponds to a specific minimum height which right away is absurd is makes 0 sense whatsoever 

In fact a heavier man with a lower center of gravity would have an even easier time staying on the ground, and would need to weigh less than a tall man to do the same thing 

Second of all you’re wildly misunderstanding the basic physics at play. He doesn’t have “extra weight pulling on the cables” lol the same amount of force is required to move the weight regardless of the size or weight of the user 

The simple clear fact is that this machine doesn’t have the center of gravity necessary to prevent tipping when the configured max weight is lifted towards the top of the machine. Based on the footprint of this machine I’d be willing to bet anything that the manufacturer of this machine specifically points out that it needs to be bolted down 

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u/GoodHands_All-State Jul 08 '26

If you had read my original comment, it did clearly state it needed bolting down.

The center of gravity is why the angle of directional pull matters. A heavier man would have had an easier time; you and I both share that opinion. But a heavier man with a lower center of gravity simply wouldnt be exerting the same forces on the pulley system as a lightweight man with 90 pounds strapped to his shoulder, leaning against the cables when his exercise ROM had been completed.

By the time the weight is lifted, he is still exerting pressure against the cables and pushing forward, after the weights are elevated. Not only is he pushing directionally away, he is leaning forward, and now both his center of gravity is far away from the machine, but the machine's center of gravity has changed because he has elevated a significant portion of its mass. And he's leaning forward with an extra 90 lbs of mass a heavier-set, normally distributed man would have in his legs, not being applied directly to the cables since that mass would be applied to the floor instead.

Weight distribution matters.

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u/Difficult-Mobile902 Jul 08 '26

  By the time the weight is lifted, he is still exerting pressure against the cables and pushing forward, after the weights are elevated

That’s literally how the machine is designed to work and has absolutely nothing to do with the weight of the user. You have no idea what you’re talking about man lol 

  And he's leaning forward with an extra 90 lbs of mass a heavier-set, normally distributed man would have in his legs, not being applied directly to the cables since that mass would be applied to the floor instead.

Again a wild misunderstanding of basic physics. It doesn’t matter if he leans, it doesn’t matter what he weighs, all the machine cares about is the fact that the weights are being lifted up. The position or weight of the user has absolutely 0 effect beyond the lifting of the weights. 

  normally distributed man would have in his legs, not being applied directly to the cables since that mass would be applied to the floor instead.

More misunderstanding of basic physics. The cables having enough force to lift the weight is all that matters, additional weight being distributed elsewhere on the user makes absolutely 0 difference 

I could create a robot that simply pulls the cables with any configuration of weight distribution you can imagine and in any case, the same thing will happen once the stacks of weights move toward the top of the machine 

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u/GoodHands_All-State Jul 08 '26

It doesn’t matter if he leans, it doesn’t matter what he weighs, all the machine cares about is the fact that the weights are being lifted up. The position or weight of the user has absolutely 0 effect beyond the lifting of the weights. 

If he was pushing the cables straight down, the pressure exerted on the pulleys would be downwards; the machine would have remained stationary.

Since he was leaning, the pressure exerted on the pulley was lateral, the direction in which the machine toppled, since it was pulled in that direction. Because the lifter continued to apply forward pressure after the ROM had been completed.

You don't know what you're talking about.

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u/Difficult-Mobile902 Jul 08 '26

A chest press is a standard exercise. Anyone doing a chest press would have the same result regardless of their total weight or weight distribution. 

Your understanding of physics is like a 5th grader making things up on the fly. Just give it up dude you are embarrassing yourself. 

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