Developing a riding buddy sometimes takes time. we don't all start out at the same fitness level and it can take time before we can gel into a group. The way we work it today is someone will always fall back to ride with someone who gets dropped. The A and B riders will start out together and at what ever point the pace picks up past the ability of the B group we break up. If the B group gets too fast and we drop someone then one of us will drop back to pull them up or ride with them till we get to a regroup point or the coffee shop. I can't remember ever dropping someone I invited or agreed to ride with no matter what pace they set. And it has paid me back on those long climbs when it is all I can do to keep up and they have to wait for me.