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(quadancer @ Apr. 12 2007,20:59)</div><div id="QUOTEHEAD">QUOTE</div><div id="QUOTE">Considering that the smallest dip of one side of the bar would have a multiplied effect due to the longer length of the fulcrum from the axis (your hand), it stands to reason that unless your form is absolutely perfectly symmetrical, you would have to use some of your synergistic muscles a bit more to control the bar from rocking.
So if you're used to a shorter bar, a bit of added balance issue would be noticable with a long one, and one could easily interpret that as more weight, even if the bar isn't actually 'rocking'.
Well, that's what I think, anyway. What do I know?</div>
Makes good sense to me , I notice significantly more stimulation of the core esp. the obliques when using the longer bar - which fits the idea that the longer bar requires more effort to balance .