Barbells - Everything you ever wanted to know
I don't think a thread like this exists for the barbell, so I wanted to start one. The Olympic barbell is one of the most important purchases one can make for their home gym. A barbell is the interface to the weight and although they may all look similar to an untrained eye, there are actually a lot of differences and a lot of reasons for someone to choose a specific bar.
Below I'll talk about the characteristical differences which will hopefully help people make informed decisions about which barbell is right for them.
Shaft diameter is one of the most important characteristics and determines what the bars intended use is.
[u][b]Shaft diameter[/b][/u]:
[<25 mm][Technique/Junior bars] - 10kg or less, used by youth and/or for technique work
[25 mm][Women's Weightlifting bar] - These are 15kg womens bars per IWF specification [1]
[27 mm][Deadlift bar] - These bars tend to longer and more flexible to allow lifters to deadlift more weight.
[28 mm][Men's Weightlifting bar] - These bars offer good whip for Olympic Weightlifting. The IWF bars are of this diameter [1]
[28.5mm][General/Crossfit bar] - This is one of the most common shaft diameters and is traditionally a good compromise between 28mm and 29mm, offering some whip
[29 mm][Powerlifting Bar] - These are stiff bars and offer a minimal amount of whip. The IPF PL bars are this diameter [2]
[30+ mm][General purpose/beater bars] - Typically beater bars which are made to fit a certain price point. It's a way for the bar manufacturer to use lesser grade steel without the bar deforming under commercial use.
There are of course some of the exceptions to the above and some weightlifting bars come with powerlifting markings and vice versa. For someone who competes the choice is simple, buy the bar (or bars) which match the federation's specifications. Those who don't compete will have to use their judgement based on the type of lifting they do, their goals, their experience levels, whether they want a single do-it-all bar or multiple and so on.
[u][b]Whip[/b][/u]:
Whip refers to the fact that the bar bends under load. In dynamic movements, such as the clean & jerk, the energy is stored in the bar and is used to accelerate weight upwards. The closer the grip is to the center of the bar and the further out the weight, the more the bar will deform, given that all other variables stay constant.
All bars have whip, however the diameter of the shaft and the distance of the weight on the bar will determines the amount of whip a bar will have. There isn't a qualitative difference in whip between quality bars of the same diameter[3]. Additionally, tensile strength ratings tell you nothing about whip. So, for example, don't assume that a 215k psi 28mm bar is stiffer than a 190k psi 29mm bar. It isn't.
[u][b]Specifications/Markings[/b][/u]
Although a 28mm bar is traditionally a weightlifting bar, it doesn't mean a manufacturer can't add powerlifting markings or even markings with dimensions of their own choosing. For example, the Ivanko OBS-20KG bar has 3 sets of rings (see below). Additionally, unless specifically stated, do not assume that a single set of markings on a 28mm bar will be to IWF spec and 29mm bar will be to IPF spec. Check with the manufacturer.
If you compete or plan on competing, this is the second-most important feature you must look for in a bar, after diameter.
[img]http://www.ivankobarbell.com/content/6ziydn6c0v_248.jpg[/img]
[u]REFERENCES[/u]:
[1] [url]http://www.iwf.net/doc/technical.pdf[/url] (page 31)
[2] [url]http://www.powerlifting-ipf.com/fileadmin/ipf/data/rules/technical-rules/english/2015_V2_IPF_Technical_Rules_Book_2015_classic_rules_in_back_section.pdf[/url] (page 6)
[3] [url]https://www.youtube.com/watch?v=ttlpKdeTWDU&t=20m13s[/url] (20 minutes 13 seconds)