Pulley's on machines

[evansss]

I was doing rope pulldowns on a different machine than i usually do and noticed the weight was considerable heavier. 80 pounds on this machine felt like 140 on the other one. I noticed this machine had 2 pulley's and the other one that i usually did it had 5. Obviously pulley's are simple machines that help aid work, but to what extent?

 

[huskyguy]

It is a basic physics problem depending on the placement and the size and angle of the pulleys will determine to what factor the pulleys are reducing the load. There is probably a simple equation based on those measurments.

 

[MANOWAR]

Yea thats the problem with going to different gyms. Not only are the cable machines different, but the free weights and plates are also at different weights. 45 at the high school weight room feels like 25, and 45 at LA Fitness feels like 55. I can't tell what's accurate and what's not. Not only that, when I sneak some weights into the locker room to weigh them, every scale is different too! wtf

 

[Melbourne]

Machines are totally unreliable. Not only are the angles of each machine slightly different, so is the amount of friction in each mechanism. Finally, the numbers on the weights in the machine sometimes don't seem to relate to the actually weight. Sometimes I think its just a number.

Freeweights can be unreliable too, and can mislead you when it comes to knowing how much you're lifting.

Just to top it all off, scales can be old, poor quality or not set up correctly (eg placed on a soft surface like carpet) so they can't always be relied on to give you a proper reading.

 

[Jusee]

One is kilos and one is lbs. I bet big $ on that.

 

[evansss]

One is kilos and one is lbs. I bet big $ on that.

Maybe, but the labels are the exact same on the weights, and they look to be about the same size. Although the comparision in what felt the same was about the same or a little bit more (80 on one machine vs 150 on the other one)

 

[Vennom96]

It has nothing to do with the angles or lbs vs kgs. The more pulleys a machine has the easier/lighter the load with be. If you take the exact same machine and the exact amount of weight and use one pulley, the weight will be a lot heavier than if you were to have say, 2 or 3 pulleys to the exact same setup. It's simple physics.

http://en.wikipedia.org/wiki/Pulley

 

[evansss]

It has nothing to do with the angles or lbs vs kgs. The more pulleys a machine has the easier/lighter the load with be. If you take the exact same machine and the exact amount of weight and use one pulley, the weight will be a lot heavier than if you were to have say, 2 or 3 pulleys to the exact same setup. It's simple physics.

http://en.wikipedia.org/wiki/Pulley

agreed. but now that i think of it, it was the same brand machine too, shouldnt the labels be different to acount for this?

 

[Vennom96]

agreed. but now that i think of it, it was the same brand machine too, shouldnt the labels be different to acount for this?

Well the machine manufacturers don't take into account the pulleys. Each weight plate weighs x amount of lbs so they label each plate the amount it weighs. If you were to lift the stack of weights and put it on a scale, it would match the numbers on the weight. I don't think the "weight" can really be accurately labeled b/c for each pulley there is, it takes resistance off.

 

[evansss]

Well the machine manufacturers don't take into account the pulleys. Each weight plate weighs x amount of lbs so they label each plate the amount it weighs. If you were to lift the stack of weights and put it on a scale, it would match the numbers on the weight. I don't think the "weight" can really be accurately labeled b/c for each pulley there is, it takes resistance off.

its somthing that should be taken into account because it seems as it throws the weights off in a fairly significant way. i saw the same machine with 1 pully as opposed to 5

 

[adidamps2]

its somthing that should be taken into account because it seems as it throws the weights off in a fairly significant way. i saw the same machine with 1 pully as opposed to 5

honestly i wouldnt worry to much about it..just adjust wts till they feel comfortable and lift from that wt on with "that" machine. if it 100lbson this machine but 50 on a differnt one it doesnt really mater. its how hard your working in the end. just know the machines when you use em. but i understand what you are saying over all though.

 

[blackjack]

the numbers are arbitrary, just use whatever load lets you work in your desired rep range.

 

[adidamps2]

the numbers are arbitrary, just use whatever load lets you work in your desired rep range.

thats what i was trying to say..much easier wording than mine...lol

 

[blackjack]

thats what i was trying to say..much easier wording than mine...lol

 

[evansss]

agreed im just trying to keep track of the numbers so i can go up everyweek. ill just stick to using the same machine though no biggie.

 

[adidamps2]

agreed im just trying to keep track of the numbers so i can go up everyweek. ill just stick to using the same machine though no biggie.

you really dont have to do that either just keep track of the differn machine..even if there the same jsut for log purposes give'm 2 differnt names or give one a special identifier..like hi-lat pulls 2..that way you can still keep track of progress even if its a differnt mach.