The chain always falls off toward the bike frame, off of the smaller front cog.

It's likely not the rear derailleur since I'm usually in the middle rear cog.

It might be the front derailleur since when I put it as close to the chain as possible, the chain doesn't fall. This is again, on the third cog up in the rear and the smaller cog in front.

That said, doing the above might just be preventing the chain from falling because of its potential real problem: chain, crank set, or cassette wear.

What are your opinions?