Going from 26 to 32 will probably require a different rear derailleur. If you provide info with what bike you have and the specs, you'll get more accurate info. Here's a basic doc: Rear derailleurs buying guide | Wiggle Guides. If you google "long cage vs short cage" you'll get lots of info. Are you going to install the new cassette? If your LBS is going to do it, they would know if you need longer chain or derailleur.