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Calibrating Lifeline Chest Expander Cables - An Experiment

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#161 [url]

Jul 31 11 4:47 PM

I hope this Lifeline stuff gets sorted out soon because all these Lifeline posts have really started to monopolize the board

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#162 [url]

Jul 31 11 4:54 PM

BigBruvOfEngIandUK wrote:
I hope this Lifeline stuff gets sorted out soon because all these Lifeline posts have really started to monopolize the board

I'm sorry BigBruv.   It won't be going on for much longer.

Lifeline could sort it all out in half an hour if someone there actually got off their butt and checked my figures. 
  

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#163 [url]

Jul 31 11 5:11 PM

I appreciate your friendly sentiment Macky, i would also like to keep this on that level, and continue to discuss this until we either reach a consensus or agree to disagree.


Since i did make some measurements yesterday, i'll refer to that.


I did this, only instead of a scale i used physical weights. With a 16 inch orange cable and 25 pounds the cable stretched to 3 times its length.
This gives us two points to consider. The length of stretch and what does the 25 pounds mean?

Regarding the length of stretch, we all originally thought it should only stretch to 2x the length. Then Lifeline came out with the FAQ which stated 3x, and to add confusion, Ray said 2.5x !!!

Now, my experiment says it is 3x, and Kevin said this was worked out in 1970! So over the years some copy writer messed up, some guy in QC (a field that only attracts the best and brightest) messed up. Over the course of 40+ years not hard to believe. Along comes Macky and someone actually has to go back and dig up the original guidelines which is what the FAQ represents. So for that reason, i'm going along with the 3x number.

Moreover, i forwarded the post to Kevin, who confirmed the 2x was a copywriting mistake, and he aims to right that. (He answered me on a Saturday BTW the same day i forwarded him the message.) 

So with that, i hope we can agree, 2x is out and 3x is in.

From there the next issue is what does the 25 pounds mean? From a physics point of view its the amount of weight the cable is holding, and that the ceiling its attached to is holding. The cable is holding 25 pounds and the ceiling is holding 25 pounds. This 25 pounds is the tension on the cable.

Now i don't know the definition of Pullweight, i've never seen it since competitive strand pulling has gone the way of the dodo, it could be that its just the measure of how much tension is on the cable. If so then Lifeline's cable rating is not a measure of Pullweight. I don't see that as a problem though, they have the right to rate the strength of the cables how they choose. And this is where i think the disconnect is between what we are saying. Its a matter of definitions. (I would love to know what someone like Fatman has to say about the meaning of Pullweight)

Now lets go back to my attempt to explain why a 50lbs rating makes sense (or not). If we can get together on this, or at least understand each other we are home free.

I think that the hanging cable is easier to think of than the cable around the scale, but hopefully i can show they will give the same result.

If you have the cable hanging with 25 pounds attached to it, measure the amount of stretch and then take the weight off and with one hand stretch the cable to that same length how much is the hand pushing? 25 pounds, not 12.5 pounds. If you reverse the procedure and with the weight on the cable unhook it from the ceiling how much is that hand holding? 25 pounds.

Again this is just Newton's law for every force there is an equal and opposite force. The force is the 25 pound weight being accelerated by gravity. The ceiling resists that force equally. 

So if you take off the weight and unhook from the ceiling one hand is providing the force of the weight 25 lbs and the other the force of the ceiling 25 pounds for a total force being applied by two hands of 50 lbs.

Since this is being applied to strength training we want to know how much both hands are doing, the 50 pound rating still makes sense. And is a reasonable way to define ones cable strength ratings. In other words lets measure how much we are doing with each hand.

If this is the official way strandpullers measure is another question, but i have no issue if LL choose to do it this way, because i know i can just cut the rating in half if i'm interested in tension, AS LONG AS THE RATING ITSELF IS ACCURATE.

Its a rating system. Once you know how to convert it to your way of measuring it works fine, just like inches in the usa and cm in Europe. However, i do think this is a good way to think of pulling strands anyway.

OK now to why LL is showing how to measure as they do.

They don't want to have to explain all this, and i don't blame them, hey even they get confused. So by simply measuring by holding the two handles, you wind up measuring the force at the two handles!

So as you stated, the force at each handle is actually 25 lbs. Now if you hook one handle to the ceiling and pull the cable to the same length how much will you measure at the end? 25 pounds! Just like before, they are equivalent ways of measuring!

  

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#165 [url]

Jul 31 11 7:14 PM

Kind of the same old thing, Macky posted some more mails from LL and suddenly it dawned on me what they are doing and why we are confused.

So the change is i now agree with what LL is saying and that their cable ratings aren't off after all (assuming they are stretched to 3x resting length)

Macky thinks LL's ratings are incorrect for strandpulling due to their way of measuring it.

Most people won't care about this discussion, its up to you if you want to slog through it.

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#169 [url]

Aug 1 11 9:28 AM

This is the second to last post here from me on this subject.

I have sent Kevin Dorsey an email requiring definitive clarification on their Chest expander cable test parameters.

The last post from me on this board on this subject will be posted when and if he gets back to me with a specific answer.

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#170 [url]

Aug 1 11 5:48 PM

lol just been skim reading this post and cant help but laugh at macky and mr bradys civilized argument on how to measure the bands

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#171 [url]

Aug 1 11 6:37 PM

Makes you wonder if this is the internet....

Well (i hope) we have said our peace and this can rest, and we can return to pulling whatever hunks of rubber we enjoy best.

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#172 [url]

Aug 2 11 1:03 AM

I never worry about the cables. I have had some Therband cables break, but wear safety goggles. I have had steel springs break too. I have the best equipment now, but for years used a beat up steel spring set made by Spenby, and did so until there were no springs left. I switched to rubber, and for a long time used thick solid rubber bungee cords. I purchased Ironmind's fabled cables, but thought they were junk. I then made my own cable loops and handles. Later on I obtained the Samson handles, and recently bought a full set of Lifeline chest expanders. I like best the Samson handles and my homemade loops.

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#173 [url]

Aug 2 11 1:20 AM

I've been wondering what you think of those Samson's. They really look like something i would like, maybe for Christmas. How is swapping cables in and out of the Samson?

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#174 [url]

Aug 2 11 1:28 AM

It's easy to add or remove cables. No need to be so lazy that you need an open type handle. I have heard that it often takes a while to order Samson cables from Mike Brown unless he happens to have them in stock.

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#176 [url]

Aug 2 11 12:04 PM

This is the last posting from me on this particular thread, on this forum.

Firstly I would like to apologise to BigBruv for subjecting him to my lengthy repetitive posts over the last two months.

Had I known he was an Admin I would have considerably abbreviated my posts.  The reason for the length of them was because I wanted anyone new to the thread to be brought up to the mark by not having to go back to Page One and work their way through it, but to pretty much hit the most recent pages and be able to gain a good idea of where I was coming from.

Kevin Dorsey's last email to me has confirmed what MrBrady had started to understand, and I along with my FAQ page inspection.  I will not go into it on here for very long,  save to say that Lifeline,  by their own mis-information consistently given out to customers at their front-end ( Carrie Jensen ) and by at least two senior personnel failing to read and understand my emails to them properly,  have wasted my time and that of others.

I tried to do something for the Lifeline owners on this forum,  for Lifeline owners everywhere,  and for Lifeline itself.  

I will not say it has been a complete waste of time,  but all this could have been dealt with in March of last year if Ray Rollins had read my emails properly and picked up on my continued assertions based on Chest expander cables being rated at TWICE their resting length,  something which Carrie Jensen had continuously repeated up to the near-present,  and which Lifeline never directly refuted ,  despite having this information before their very eyes on more than one occasion.

I will be posting the relevant emails on the Email Correspondence thread when I receive perhaps another answer from Kevin,  as to why Lifeline is so disconnected that three different parameters 2X,  2.5X, and 3X can be quoted by Key personnel, and a rocket of course for Lifeline's collective incompetence,  at least as far as its customer information is concerned.

That's it from me.  I wont be answering any questions on this thread.  Those that wish to talk to me on this subject, or any other, are welcome to email me on [email protected]   
I would ask BigBruv to remove my email address after about a week,  if he would, please.   

 

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#177 [url]

Aug 2 11 4:00 PM

Ive merged that thread with this thread because it is the same subject. This thread was already made from merging three almost identical threads because you guys keep starting new threads about it.
All anyone needs to do is read the first few posts and the last few posts to see that nothing has changed

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#178 [url]

Aug 2 11 5:43 PM

I think thanks to the efforts of forum members their has been change.

Lifeline now answers their emails, is changing the length of their cables, (ok that's a different problem) and they have had to go back to 1970 to figure out how they rated their cables in the first place.

In a way everything has been sorted out. (Though Macky might have a different opinion.)

(plus i got to go back to 1985 and review my first year physics)

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#180 [url]

Aug 2 11 11:29 PM

The ratings measure the pull of BOTH hands at 3x resting length to what LL claims to be 10% accuracy.


That did hold true for the one Orange cable i measured, though that doesn't constitute proof, its as good as i need.

Lifeline does admit that the heavier cables are not as accurate though, which is what Fatman originally discovered, but they weren't as off as he thought.

Last Edited By: MrBrady Aug 2 11 11:39 PM. Edited 1 time.

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