It won't work. Actually, you will have to really disguise the bike so they don't know it's a bike when you prepare to board. If you can disguise it and you don't say anything and they don't guess, you're in the clear. But if you get on the train with your bike, even if it's partially disassembled (as I found out this summer when I went to the burbs), they won't let you on. You have to make that reservation in advance and pay the $5, and then again, that's only on the weekends. Metra sucks.
Dunno about this one- the conductors seem to be pretty sharp, so stay on your toes, and make sure they can't tell it's a bike, but don't be surprised if they stop you anyway and kick you off. Good luck.
Koffee