15kg bar and deadlifts...

[JCR]

The "Best of the Forum" section of the September 14, 2015 SS Report featured an old (2010) thread in which stef wrote:

"Right tools for the right job. And the 15kg bar is not for deadlifts. Not. Ever. Especially mine."

I've finished setting up my home gym and since my wife will be starting SS soon, we got her a 15kg, 25mm shaft diameter nice bar. It wasn't the priciest item we purchased for our home gym, but it was not a cheap bar either: (this one, in case you're curious). Thus, we want to take good care of it and have it last a very long time.

So, the question is: Why not DL with it? What's the concern?

PS: The old thread where this was posted is closed to comments. I would have posted my question in that same thread if I had been able to.

Thanks.

[manveer]

So, the question is: Why not DL with it? What's the concern?

It's 25mm. It's much, much easier to permanently bend it through normal use than a 29mm bar made from steel with equal yield strength.

[Chebass88]

It is your bar. Do whatever you want with it. You paid for it.

I would think it would be more likely to bend due to the smaller diameter

[iamsmuts]

It's 25mm. It's much, much easier to permanently bend it through normal use than a 29mm bar made from steel with equal yield strength.

I don't think this was the concern behind the comment on the old thread. Surely it is more likely to bend by being dropped from overhead during a snatch than from a heavy deadlift.

I thought the prohibition had something to do with grip strength, tradition, or competition. It wasn't clear. Until I saw that comment, I thought that women used 25mm bars in powerlifting competitions. . . .

If you don't plan to compete, then reasons of competition are null.

Tradition has very little weight for me. If the tradition is based on reasons, then its the reasons that matter here.

As for that of grip strength. I'm not so sure. I don't use the 25mm bar, but my wife does. She has very small hands. We started with a 32mm bar. She got pretty far, but when we switched to a 28.5 she did even better. At a certain point, grip became the limiting factor. I got her a 25mm bar and she kept going up. She's pulling over 2.5 times her body weight for reps. This wouldn't have happened, at least not for a very, very long time if ever, had she stuck to a 28.5mm bar.

Perhaps using the 25mm was a mistake. But I can't see why. I'm wrong about a lot of stuff, so I welcome enlightenment.

If I had very small hands and I didn't plan on competing, I'd probably use a 25mm bar too, at least sometimes. I guess for those deep in the tradition of the sport, this might be akin to wearing a thong and carrying a purse. I'm not sure what to say to that.

[manveer]

I don't think this was the concern behind the comment on the old thread. Surely it is more likely to bend by being dropped from overhead during a snatch than from a heavy deadlift.

I agree that it would be more likely to bend after being dropped from overhead, but I can still see the bar getting bent by a heavy (>405ish) deadlift which is lowered quickly and asymmetrically. Not sure how much you can load on that bar.

I don't know - maybe you're right and it has more to do with tradition.

[ajvd]

I have a slightly (almost unnoticeably) bent 15kg bar from rogue. I seriously doubt it has ever had even 225 on it.

Also, keep in mind how expensive a 15 kg bar for competitive weightlifting would be. It'd be annoying to bend that when straps would suffice.

[Cody]

It's 25mm. It's much, much easier to permanently bend it through normal use than a 29mm bar made from steel with equal yield strength.

Not quite true. If the bars both have identical yield strengths, they would both permanently deform at the same time.

If a 25mm and 29mm bar both have the same yield strength, the 29mm bar is made from cheaper steel than the 25mm bar.

The bar you posted will be fine for the vast majority of females to deadlift with. I would be comfortable with using it up to ~400ish lbs for deadlifts.

[MBasic]

I agree that it would be more likely to bend after being dropped from overhead, but I can still see the bar getting bent by a heavy (>405ish) deadlift which is lowered quickly and asymmetrically. Not sure how much you can load on that bar.

I don't know - maybe you're right and it has more to do with tradition.

how much does your wife deadlift?
Its probably not going to matter.
skip to 9:30 on embed one
https://youtu.be/2pfLY_a5s_U?t=574



she's (Titiana Kashrina and the Chinese dude) dropping fuck ton of weight from 7 feet up. . . .granted top of line oly bar . . .but your wife is probably DL ing less weight, lowering from thighs/waist to floor under control.

Thread over

[manveer]

Not quite true. If the bars both have identical yield strengths, they would both permanently deform at the same time.

No - the area moment of inertia of the small diameter bar will be much smaller, resulting in a much higher stress for the same load. In simple bending, max stress is inversely proportional to D^3.

Edit: Think about it - you know the bar smaller bar will deflect more when deadlifting a given weight (let's say 315) and since both bars have the same modulus of elasticity, the stress has to be higher with more strain. Yield strength is a measure of how much stress it takes to induce plastic deformation, not load.

[manveer]

how much does your wife deadlift?
Its probably not going to matter.

Probably ~200, I don't know... but the original thread was about men using 25mm women's bars because they're easier to grip. In the original context, that may be what Stef was more concerned about.