Jefferson Curl: dumbells vs flat bar vs curl bar

I am currently using a wooden dowel (47inx1in) with standard plates to perform the Jefferson curls but the plates wobble a little bit too much. Any drawbacks in using dumbbells for the Jefferson curl? what about a curl bar? 

Hi Sal, no worry, KB, dumbell everything are fine.

Hi Alessandro, Thanks for the feedback.

Would Curl bar/ dumbells be an appropiate substitute for all Foundation One exercises?

It depends of the exercise, where weights are necessary you simply need a weight.