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Angle of support and strength capability

  1. Sep 24, 2014 #1
    I have been looking at new weight benches recently. Whilst I can appreciate this is not a weights training forum I think the mechanical loads and the equipment designs can best be discussed here, I´d like an engineers professional input.

    Something thats rather obvious is that as benches get more expensive the box section steel they are fabricated out of gets larger and thicker gauge. Something that isn't so obvious is that the main support of the backrest often stays in a smaller gauge steel - I can't quite work this out in my mind, that the main weight support of the bench is in such small section steel, compared to say the legs or other main supports.

    I´ve given a few examples of benches and annotated at the point in question, it seems to me this is the part which takes most stress yet it is the smallest gauge steel, even in the flat position where it will actually be taking more stress than in the incline position! In this case that one part of steel is taking a full stress if a lifter is led down on his back with it in the flat position, this bench is rated to 600lbs, that seems a lot of weight for that one 40 x 20mm part to take.

    In the flat position the part even takes more stress than in the incline position - I have to wonder why they don't make this part out of larger section steel - It´s something they hardly ever do, after looking at scores of different benches most have a small section steel support there.

    Purely out of interest the thoughts are, look forward to any feedback possible.
     

    Attached Files:

  2. jcsd
  3. Oct 8, 2014 #2
    Maybe it is just total overkill on these new benches. Look at this old school bench from the 60s/70s when Arnold Schwarzenegger was lifting, and not many people will be lifting weight as heavy as these benches took.

    Amazing how thin the tube is compared to the current models on post #1 old school.jpg
     
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