Fund raising

It can be a very good way to raise money especially if you can get some kind of hook for the event like a celebrity appearance. It can also be coordinated with another event like a concert or meal at the end of the ride.
One thing to be considered is obtaining an insurance policy that will cover organizers, sponsors and anyone associated with the event. Not sure where you are , local and state statutes vary and permits may be necessary.
Make sure you write a good hold harmless for participants and have each one sign it.
Look for corporate sponsors that will cover the fee for their employees to participate.
Determine route and or routes and if the event will allow all age groups.
Consider a charity ride does not normally require prizes or throphies as opposed to a race, however sometime prizes will be donated.

It would also be a good idea to check into the dates of other cycling events in your region. This way you wont overlap any other events reducing your pool of potential participants. Don't forget to write letters to your county commissioners and legislatures in hopes of getting public funding for your bike path. Good luck in pursuing this worthy cause.

Thanks for your info. We are just starting talks on the subject and any info will help.