Every 2nd chance offer that I have received, has taken place after a bike that I was bidding on, has ended and been sold.  On every occasion, the "seller" has appeared very motivated to sell me the "sold" bike for what my original bid on the bike was for, even if the bike sold for a higher price.

I would suggest that you inquire as to what their payment terms are, and will find that they always require a money order being sent to them, with the offer of free shipping in return.  It is quite simple to contact the original seller, and verify whether the 2nd chance offer being made to you is legitimate or not. 

Don't fall prey to the scammers out there, investigate the facts as presented, and if you still have doubts, contact Ebay for additional assistance.  We all work way to hard for our money, only to lose it to someone with less than honorable intentions.