15 people is way too many to try to coordinate and organize. Find out a few that want to go to RIDE and work it out with them. Those who truly want to go and ride are probably going to be more flexible to work with because they're more eager to get out there.
"People say that marijuana smoking is going to get in the way of my career. I say to them that on the contrary, my fighting career is getting in the way of my marijuana smoking." -Nick Diaz