Is my bar bending too much?

[Mmll]

Hi Rip

I bought a 45 lb rogue ohio power bar bare steel version. Can u please look at this video?
2 December 2021 - YouTube

The bar is straight without plates on it...but a slight bend occurs with just 227 lbs of plates on it. Admittedly they are bumper plates and the bar is resting on holders that are straight, not the j cup style...but I didnt think a power bar should be bending at all with this much weight. What do u think?

By the way the rack is shit, its cheap and slightly uneven. Floor isnt perfect but its pretty even. I really didnt expect this from a power bar. Also, this bar is actually a replacement...i sent the first one back because the exact same thing was happening. So i doubt getting another replacement will make any difference.

Is there a problem with this bar and should it be sent back? Or am i over-reacting? Thanks a lot.

[Mark Rippetoe]

Does the bar stay "bent" when unloaded?

[Mmll]

No it doesnt. I put both the spirit level and a straight edge on it when its unloaded, and its straight

[Mark Rippetoe]

It is not "bent." It is flexed. Stop squatting with bumper plates.

[JFord]

… Stop squatting with bumper plates.

Mark, Is that because of the greater lever arm distance? All six of my 45s are bumper plates (so I can use them for deadlifts too and hopefully not crack the concrete floor of my garage).

I haven’t noticed a problem with bent bars when I squat.

[Mark Rippetoe]

Yes. It's the Moment of Inertia -- the distance from the center of the bar to the center of mass of the load on the sleeves, effectively the moment arm operating on each end of the bar. It's not critical at light weights.

[AndrewLewis]

Mark, Is that because of the greater lever arm distance? All six of my 45s are bumper plates (so I can use them for deadlifts too and hopefully not crack the concrete floor of my garage).

I haven’t noticed a problem with bent bars when I squat.

With iron plates, I can feel the bounce at about 405. With rubber plates, it's apparent at about 275. Much more so in the deadlift.

Buy a platform, you'll like it.

[Mark Rippetoe]

Materials Science of the Barbell | Andrew Lewis

[JFord]

With iron plates, I can feel the bounce at about 405. With rubber plates, it's apparent at about 275. Much more so in the deadlift.

Buy a platform, you'll like it.

I built one per Mark’s instructions in the Blue Book. I’m just paranoid. The wife would kill me if I cracked the ground. Also, I’m only at 250 on squats and 330 on deads.

[Smyth]

Man, I just can’t afford an extra set of plates at the moment. I somehow never knew about this issue. Some day…