How about a completely different approach? What if MBC swamped the ride with as many people as possible? If they are going to ride at rush hour blocking traffic, running lights, etc., MBCers could encourage other behavior and join in if it turns out to be more geared towards appropriate behavior. If I were still in the Boro, I would go check it out and try to move it in the right direction. Just a suggestion.
I like the official release of a statement indicating that these types of rides are not sanctioned idea. It will be one of the positions we will need to take to get things moving with the bike plan. Someone will need to plug in at that level and Ed, you sound like the man for the job.
I would try to get it covered in the same story as the ride if possible. Don't have to grant an interview, but not opposed if you did. But at the least a press statement with the official position of the club and why. They can use the statement in the story.
Just because bicycling improvement is on the radar, it isn't a slam dunk. Little things like that can be very helpful in laying some important groundwork.