Bending barbells?

[JohnRoman]

I'm trying to get some science behind talking the gym owner into a better bar and some understanding for myself at the same time.

What actions cause barbells to bend? Not bend to impress the onlookers but the type of bend that can warp the bar permanently.

Obviously, squatting, pulling, benching enourmous weights, but what about :
- putting/dropping a loaded barbell (>= 135#) down on the bench (to move the hooks)
- allowing the bar to fall and hit on one side significantly before the other side
- a bar whipping during a squat, dl, etc.
- rack pulls (versus block pulls)

Also, if a bar is rated at X lbs, at what %age of X would you expect it to warp?

Once it is bent, should I expect it to bend more or less easily in the future?

[Mark Rippetoe]

All of these things can bend a bar. Extremely shitty bars like those 30+mm bars sold by Gill can bend for no apparent reason. Since the rating numbers are meaningless, any % of that number is also meaningless. Bending it once will not change the ability of the bar to bend in the future.

[Josh K]

Do bent barbells fill any sort of niche? There are two fairly bent bars in my gym that look nothing like the rest, much darker (I don't know whether they're coated or bare steel). They do, however, have a very nice feel to them and are more likely to be available since everybody is drawn to the nice shiny straight bars.

Press and bench press feel fine, as does squatting. Haven't tried deadlifting or power cleaning with them. Anything I should completely avoid using them for?

Also, they have 3 sets of markings, the first set is almost at shoulder width and I've never seen that before.

[veryhrm]

Tom Lincir, founder and Pres. of Ivanko, claims, convincingly imo, that tensile strength of the steel is the key metric. (Really it's yield strength, but, afaict, they vary together for steel of this kind).

...
All the imported bars from China have a very low tensile strength and lower yield strength. Their bars can be bent by doing an explosive deep knee bend with 300 pounds and reversing direction fast.
...
Bars rarely bend from dropping when the plates hit first. It almost always happens when the bar hits first, such as on a power rack. This makes me wonder why, with all the great designers around, none of the gym equipment manufacturers can design and manufacture a shock absorbing power rack, or a power rack designed so that if a loaded bar drops, the plates hit first.

Back in 1987, a strength equipment designer by the name of Jim Sutherland conducted what he termed a "serious test" on 11 Olympic bars to determine the best bar to sell to serious power rack trainers. Jim was the head of research and development for Universal Gym Equipment, the major strength equipment manufacturers at that time. He tested Uddeholm, Eleiko, York, Ivanko, Superior, Hastings, Texas Power Bar, Malone, and Billard. His test consisted of dropping weight-loaded Olympic bars from a three-foot height onto 1-1/4" diameter heat-treated power rack safety bars. He started with 350 pounds and incr eased the weight until the bar developed a permanent bend. Seven bars developed bends ranging from 1/2" to 3" in the 350 – 700 pound range. Eleiko and Udeholm made it to 700 pounds before bending. Two bars made it to 1100 pounds without developing bends: the Ivanko OBX-20KG and the Hastings Manganese Alloy bar. The Ivanko bar at that time was made of 185,000 PSI steel.
http://ivankobarbell.com/press/how_t...c_bar_2012.pdf

(though the pdf says 2012 it's a reprint from 2003. So i think it's quite possible that there are some better Chinese bars out there now. )

One of the reasons i want a B&R bar is because it is strong steel. The blurb on rogue says 200K yield strength (could have sworn they used to list tensile strength...) so if you get one of those, as long as York ships out a straight one, it should stay that way unless you drop it onto safeties or something else w/ quite some weight on it.

[Mac Ward]

Dropping the bar CrossShit style with no weights on it seems to really do a number on them.

[Mark Rippetoe]

Do bent barbells fill any sort of niche? There are two fairly bent bars in my gym that look nothing like the rest, much darker (I don't know whether they're coated or bare steel). They do, however, have a very nice feel to them and are more likely to be available since everybody is drawn to the nice shiny straight bars.

Press and bench press feel fine, as does squatting. Haven't tried deadlifting or power cleaning with them. Anything I should completely avoid using them for?

Also, they have 3 sets of markings, the first set is almost at shoulder width and I've never seen that before.

I squat with a bent bar because it doesn't roll down the back if the bend is facing up. I see no reason to press or pull with one, because if you fail to place the bar with the bend pointed straight up, it will shift in your hands as it rights itself.

[veryhrm]

I squat with a bent bar because it doesn't roll down the back if the bend is facing up.
...

You've mentioned the bent bar before, and I have a question about it: As your back angle changes during the squat, if the bar doesn't rotate with respect to the floor then the bar will roll that same amount with respect to your back and hands. This will tend to move it slightly down your back on the way down and back up on the way up. Do you feel this? And if so where do you absorb this movement in your hands / arms ?

(This isn't just idle speculation, a bar i squat with, though it is straight, has bushings on it with characteristics such that the plates spin backwards when i finish a rep. I'm thinking that the little extra torque i'm feeling is causing me to try to press the bar too hard against my back and contributing to my elbow grief.)

[Mark Rippetoe]

I see your point, but it doesn't move enough that I notice it.

[lwoodroff]

I tried to Deadlift with a bent bar at my gym a couple of weeks ago without realising it. The way it twisted and tried to roll out of my hands even at piffling weight was both painful on the hands, tricky on grip and disturbing to my confused brain. Squats and bench have been fine though and there are a couple of decent bars I can borrow from a locked room if I ask.

[David Kirkham]

Tom Lincir, founder and Pres. of Ivanko, claims, convincingly imo, that tensile strength of the steel is the key metric. (Really it's yield strength, but, afaict, they vary together for steel of this kind).

From the above Ivanko pdf. "Aren't you afraid that the rigidity [of the rack pins] will cause the Olympic bars to bend on impact?" This is an extremely common misconception regarding steel (assuming the diameter and/or length of the pins didn't change).

My comments are restricted to the commonly used steel alloys--not stainless steel alloys.

Tensile strength has nothing to do with the stiffness of steel.
Alloy content has nothing to do with the stiffness of steel.
Hardness has nothing to do with the stiffness of steel.
Young's modulus (stiffness) for steel is 30,000,000 psi, period. Plain old mild steel (the stuff our racks are made from) is just as stiff as 300M heat treated to Rockwell C 55 (the stuff NASCAR connecting rods are made from). It is a strange, but true fact of steel.

Metal is what I do. You can see our website here:

www.kirkhammotorsports.com
We also have a zillion photos on our Facebook page here:
https://www.facebook.com/KirkhamMoto.../photos_stream

I only post our links so you can see I have spent my entire professional life in the high performance metal area...and there are a lot of VERY stubborn myths that persist with regard to stiffness being related to tensile, hardness, and alloy content of steel. I am grateful I can finally post my opinion (hopefully worthwhile) on this site and not just ask Rip and everyone else novice questions. I looked up the Ivanko pdf you listed today (along with eye-opening writings of other barbell manufacturers) and found so much disinformation out there I thought Obama had printed it. These types of misconceptions are wide-spread and virtually impossible to straighten out.

I am in the process of writing an article on this for Rip. Four weeks ago a heart attack got in my way and threw my schedule off. Nevertheless, I was back in our gym tonight, teaching my boys how to squat. I even squatted 111 lbs 3 x 5 (less than 1/2 of right before my MI). My youngest got under an 18.5 pound bar with sweet form. I even went out into the shop and cut a 1 inch bar so he could learn the ways of the force.

I can see I need to get writing.