Campagnolo QS Front Derailleur/Shifter Compatability I have older Campagnolo Chorus 10-speed shifters. They are marked 'Carbon BB System'.  

I am replacing my front derailleur and have a spare 10-speed Record QS front derailleur. QS stands for Quick Shift. I understand that the QS system changes the ratio that operates the derailleur. 

Will an older non-QS lever work with a QS front derailleur?
In short the answer is Yes.

From the installation &amp; maintenance manual


  The new QS Ergopower controls provide for fast operation and a lower shifting force if used with the new QS front derailleurs. 
  
  The QS Ergopower controls and the QS front derailleurs can also be used with non-QS Ergopower controls and front derailleurs.  However in this case please note that:
  
  
  QS Ergopower controls with non-QS front derailleurs could require a higher force to effect shifting.
  Non-QS Ergopower controls with QS front derailleurs will require at least two lever movements to effect shifting.