After properly adjusting the cable to your front-derailleur (FD), after riding a bit - the cable will stretch and the cage of the FD may well start rubbing. Now you can loosen the cable anchor-bolt and pull the cable tight again and secure the bolt with 48 - 60 ip. OR you can have installed an inline barrel-adjuster and give it a small tweak to re-adjust the cable without even getting off the bike. Or slowing down.

Here are the barrel-adjusters I recommend:

http://www.biketoolsetc.com/index.cg...rrel-Adjusters

Here's one ready to roll: