Rides in September?

Hello there! My name is Jamie Lee Fontaine and I am an avid cyclist who lives in Baltimore, Maryland. I am going to be in Chicago on business September 19th and 20th and was wondering if there are any regular rides (preferably faster rides...averaging 16ish mph or more) occurring on either of those dates? I'd be very interested in taking part in an organized ride. Also, is there anywhere I would be able to rent a bike from while I'm out there?

In Baltimore we have a weekly ride called the Six Pack ride which is essentially a fast-paced unplanned route for anywhere from 10 to 40 cyclists (depending on weather and whatnot). We make multiple stops at monuments or notable spots.  We also have a monthly bike ride called Bike Party on the last Friday of every month that's a little more recreational, but a blast.

Anything like this?? Any feedback at all is appreciated. 

-Jamie Lee