Hello fella's,
I currently have an older trek road bike with indexed downtube shifters. I've been doing some touring on this bike and now want to put a triple crank on it. I've got a new long cage rear derailluer, the correct bottom bracket, and a sugino triple crank, my question is do I need a new front derailluer as well? the current set-up on the bike is a double crankset.

any help would be appreciated, thanks in advance.