This is the most common back training issue I see in gyms every day. Guys are trying to “pull” on the bar or handle instead of properly engaging their backs. This not only places more emphasis on the biceps instead of the back, but it also causes a decrease in power and weight.
Instead of pulling with your hands, concentrate on EXPLOSIVELY driving your elbows back. This will help you use more weight, get a better contraction and build a beefier back.