a friend of mine has started doing these casual bike rides on friday evenings in and around downtown. the idea is to get people out on bikes, to learn about how to deal with traffic, rules of the road and such. they start at a different venue every time, usually a local business or restaurant. i've done the first few rides and it's pleasant but no one seems to follow the rules of the road and some people show up with little or no riding skills. one lady panicked in a stop situation and put her feet down to stop the bike instead of using her hand brakes. anyway, the first few rides were manageable with 20-30 people showing up. this time there are over 100 people showing up. i think it's awesome that that many people are interested in just cruising around on bikes on a friday afternoon however it's getting to be way too many people to be safe. my friend is now trying to get people to help lead smaller groups and has asked me to be one of the shepherds. it's for a good cause but i don't want to be liable for anything that happens (and it will given the number of riders). how do i not be a dick about not helping out with this?