Materials Science of the Barbell | Andrew Lewis Materials Science of the Barbell | Andrew Lewis - Page 2

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Thread: Materials Science of the Barbell | Andrew Lewis

  1. #11
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    Since most companies don't advertise yield strength, it does make it difficult to use it to determine how high quality a bar is. Is this something they would know if asked? I haven't seen it anywhere. Nonetheless, it's a very interesting article.

  2. #12
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    Quote Originally Posted by AndrewLewis View Post
    No it's not, because you'll just be one inch into an ideal deadlift if you set up correctly. If your gym friend noticed you were losing tightness as you pull the bend out of the bar, it seems likely you're not setting up tight enough. You also might be "jerking" the bar off the floor by accident.
    He said he has got into the habit of pulling out the slack prior to bringing his shins to the bar. I can’t say that it feels particularly awkward for me, this was just his observation. I’ve taken several videos on the intensity sets and I look tight. He mentioned it on the volume sets which I don’t record and I use straps-probably just getting a bit tired as I’m doing 5x5 at 80%. I’m just looking for any edge that I might be missing, so, if bar bend isn’t a problem that’s fine. Cheers for the reply.

  3. #13
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    Quote Originally Posted by JJ23 View Post
    Since most companies don't advertise yield strength, it does make it difficult to use it to determine how high quality a bar is. Is this something they would know if asked? I haven't seen it anywhere. Nonetheless, it's a very interesting article.
    Ask them what steel they use for the shaft stock. Should be 4140 or some version of alloy steel.

  4. #14
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    Quote Originally Posted by Mark Rippetoe View Post
    Did you not read the article?
    I read the majority of it Mark, I will confess it was late at night and I only read the first 3/4 of it in depth, skimmed the remainder as what I did read was mostly a rehash of my engineering classes. I'll be more attentive in the future. I listen to your youtube videos while I train at night. It's a routine now, listening to the comments from the haters as I do my squat warmup sets.

  5. #15
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    Quote Originally Posted by JJ23 View Post
    Since most companies don't advertise yield strength, it does make it difficult to use it to determine how high quality a bar is. Is this something they would know if asked? I haven't seen it anywhere. Nonetheless, it's a very interesting article.
    They absolutely have that information. They may just choose not to share it. Untreated 4140 will have a yield strength of about 60ksi. Most steel mills have gone integrated (they pour, form, and treat the steel), and there's not a lot of money in untreated steels unless you're good at a low price, volume operation - see China. If they bought 4140, it was probably treated prior to leaving the steel mill. The question becomes "what specifically was done to it?"

    It's also important to remember that Steel Company A's 4140 may have different properties than Steel Company B's 4140. Everyone has their own special recipes, except if they're following specific standards such as SAE. If you want to know more about these standards, you can find more here. Most of the information about nominal mechanical properties can be easily found based on the SAE standards.

    Quote Originally Posted by Nockian View Post
    He said he has got into the habit of pulling out the slack prior to bringing his shins to the bar. I can’t say that it feels particularly awkward for me, this was just his observation. I’ve taken several videos on the intensity sets and I look tight. He mentioned it on the volume sets which I don’t record and I use straps-probably just getting a bit tired as I’m doing 5x5 at 80%. I’m just looking for any edge that I might be missing, so, if bar bend isn’t a problem that’s fine. Cheers for the reply.
    I'd say his habit is a mechanically poor decision. Deadlifting a force of 200lb on a bar loaded to 500lb will still be advantaged by the standard pulling position. The same is true of 300lb, 400lb, all the way up to the bar's weight.

    Like I implied, my first thought is "do it correctly to make it work well" instead of looking for a work around that I don't think has good mechanical reasoning.

  6. #16
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    I really want one of these short barbells from Texas Power Bars. Youíve inadvertently sold me on it.
    How do I get them to build me one exactly like yours?
    I like the fact that it makes deadlifts harder due to lack of whip, and also that it precludes sumo.

  7. #17
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    Quote Originally Posted by AndrewLewis View Post


    I'd say his habit is a mechanically poor decision. Deadlifting a force of 200lb on a bar loaded to 500lb will still be advantaged by the standard pulling position. The same is true of 300lb, 400lb, all the way up to the bar's weight.

    Like I implied, my first thought is "do it correctly to make it work well" instead of looking for a work around that I don't think has good mechanical reasoning.
    He is young and very strong for his size, so I expect he can do things inefficiently and get away with it. I’m going to stick to the SS method as it’s worked fine for 3 years injury free and I’m still making small PRs despite being old. My weakness isn’t getting the bar to break anyway, it’s from above the knee until lockout. If I’m going to fail, then that’s where it will happen. So far I’ve never failed a lift except in the early days when I tried pulling an extra 20Kg for a single, so I’m happy enough with the technique and will work to polish the top part of the pull.

  8. #18
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    Quote Originally Posted by John Watson View Post
    I really want one of these short barbells from Texas Power Bars. You¬’ve inadvertently sold me on it.
    How do I get them to build me one exactly like yours?
    I like the fact that it makes deadlifts harder due to lack of whip, and also that it precludes sumo.
    Email them with this article. Buddy and Mitch had good customer service. This is their "contact us" email: team@texaspowerbars.com

    If they didn't write it down, then the main specs are that it's an SS bar except
    -Collar to collar length is 30.5" (I would recommend buying a 32" - I'm 5'9" and it fits me perfectly with my pinkies an inch from the collars)
    -Knurl is course
    -There is no center knurl
    -Total mass is 20kg so the balance is made up in sleeve length.

    I wanted a course grip because I have tiny hands and grip is tough for me. I'm sure you could ask for the knurling the SS bar has.
    Last edited by AndrewLewis; 10-31-2020 at 05:41 AM.

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    Quote Originally Posted by Nockian View Post
    My weakness isn’t getting the bar to break anyway, it’s from above the knee until lockout. If I’m going to fail, then that’s where it will happen.
    Mine too. I donít film myself, but I have some ideas when I get the set right on the next try. It seems that I fail when I am not able to keep my back tight the whole way. This usually happens because the bar rolls away from the mid foot during the set, which makes it harder to squeeze the back properly, so I can pull part of the way, but fail at the top part. It seems to me that the guy in the gym is onto something.

  10. #20
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    Quote Originally Posted by AndrewLewis View Post
    Thank you. I'm glad you liked it.


    Thank you for the compliment.

    The stress-strain curve is from a real tensile sample of steel, so I'm curious what about it makes you believe it's not correct for steel.
    Itís missing the upper and lower yield points that give you that small bump as you go into the plastic range.

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