Bike Rentals

I'm from Georgia but am likely going to fly up to Chicago to visit my girlfriend in late July.  She goes to school here but stays with family during the summer and she wanted me to meet her family (god save me).  We'll be in Northern Chicago suburbs and I was looking into doing the Lake Zurich sprint triathlon on August 2nd.  I'd rather do the Muddy Buddy on the 2nd but I doubt I'm going to find a partner that is going to want to be held back by me.  Nor is my gf up to the task of the Muddy Buddy.

Anyways I think it costs close to $175 to fly my road bike (it'd be cheaper to fly a person and use them as a bike) nor do I have a bike carrier.  So my next option is renting a bike.  I do not care what kind of bike it is.  It can be a full on triathlon bike that would make any IM champ drool, decent road bike or even a mountain bike (as long as it has lockout on the shocks).  I can bring my own clipless pedals/shoes.

If anyone knows of some reputable bicycle shops I could call or have my gf check out that'd be appreciated.  I am on somewhat of a budget (would not like to spend more than $100) so the cheaper the better.  Also since the race is on Sunday I'm guessing shops won't be open for me to return the bike.  So I'd pick it up on Saturday and have my gf return it for me on Monday since I'll be leaving later on that Sunday.

Any help is appreciated
Mark