Hey Rodney,
I worked for American Cycle and Fitness for awhile, they supposedly sponsor a team of their own so I am not sure how interested they will be (as an employee you'd never know however, they never seem to say anything about their team).
Some other companies to consider, and I could see about getting some contact information for you, would be:
Tifosi (sunglasses manufacturer, smaller but they are in almost all the small bike shops around here)
Domino's Pizza (Being local to Michigan they have a good community outreach program)
Rochester Mills (They have a small bike club of their own but not competitive)
Chrysler (we are in their backyard afterall)
Lifetime Fitness
I think there is quite a wide group you could approach abotu sponsorship, the question is what are you asking from them? If money, then how much? Do you have a structured donor system to reward them for their contributions? For instance, if they give you $500 what do they get... mention on the website, a patch on the jersey, etc.
I have to admit I am not sure how you guys want to do this but I'd recommend a three tier system, find 1 big "gold" sponsor, then 2 or 3 "silver" sponsors, and then 5 to as many as 15 "Bronze" sponsors, with each tier getting a predefined representation. Otherwise I am not sure how you will sell a sponsor on the club.
Also, and sorry - I have a full time job and all the meetings that have been held since early last fall have been either when I am at work or in class - but I am not sure if you are fielding a mountain biking team or not. Unfortunately I don't have the time to spare to join the team but I'd like to train with you guys. I mountain bike 3 or 4 times a week in the evenings and plan on dragging my road bike out one of these days for a ride.
I'd like to see this work for you guys though, if you get back to me with what structure you are working off of for the sponsorship and what you are offering sponsors I'd be happy to track down some contact information for you for potential sponsors to contact at your leisure - including American Cycle and Fitness.
Just get back to me,
Adam