Really, your balance issue may be more complex than that. BleeckerSt_Girl could really help if you tried to be more specific of what's unbalanced.

I was having a balance issue recently and was about to modify the whole bike until BleekerSt_Girl pointed out to me that my saddle was right above my petals. Something as minute as that! It made a world of difference. Soo... check you saddle, if its above your petals, slide it back!

Even the best of bike masters would have a hard time correcting every single aspect of your comfort.