I went on a bike tour with a competing company last year and it was great. This year I decided to try out Bike Chicago's tour. I showed up with a friend about 15 minutes before but alas, there was no guide. The manager/shop attendant told me that the guide was sick and that if I was still interested, should try tomorrow. So we rented bikes that day instead and it was gorgeous. The next day my friend and I decided to return and this time the guide did show. We rented a bike for $11 an hour to take the published ""free tour"" and it was ok, nothing special. The guide was more into pointing things out then stopping to explain. I calculated that we spent the first hour and a half picking up new guests at their other locations. The tour itself was just along the lakefront. I'm not sure how long they have been doing tours but I would not recommend it. I would, however, rent a bike from them.
Pros: rent a bike instead of the tour
Cons: the tour was a bit bland - more of a ride