We've all been there, right? You're on a group ride and it gets separated. Someone forgot to "post up," or wait at the turn for the rider behind.
This has happened so many times now, I can't even count. It happened day 1 at our High Sierras event and despite the pre-ride lecture and a threat that any violators will get a kick to the nuts, it happened three more times the next day! It happened again at Death Valley a month or so ago and the rider left at the turn wasn't too happy (right, John?).
This video of our High Sierras ride opens up with a walkie talkie conversation I had w/Brad Barker where he asks which way they are supposed to turn because no one posted up!
I think we all get both excited, tunnel vision when we ride, as well as fatigued and just forget. It can really mess up a group ride and even cause safety issues if someone goes down or gets lost.
Leap frogging is where the lead rider waits at any kind of turn for the rider behind. When the rider behind comes, they signal each other to acknowledge being seen and then the lead rider proceeds while the second rider then waits there for the next or third rider.
I recently saw a different method employed by Jimmy Lewis at his off road training class where he would tell the second rider not only to wait at the turn, but not to move until the last or sweep ride came to that turn. What this does it ensure no one blows by turns without waiting and creates great assurance that the group will stay intact.
Let's say you are the second rider behind the leader in a group of five riders. You are told to post up at a turn and then then wait as riders #3 and 4 pass you. When rider #5, the sweep, comes, you then resume the ride and are rider #4. This happens at each turn and after just two turns, you are back to the #2 spot. Each rider basically gets rotated in order.
The only downside to this I think is that the more advanced riders want their position up front and don't like to be stuck behind a slower rider. That faster rider could always pass (safely) but then they are going to find themselves posting up at the next turn and going to the back of the line again.
I think this modified form of leap frog is best for larger groups and groups with a larger range of experience where "issues" are more likely to crop up. You probably trust the original leap frog method with riders you have ridden a lot with, but I will start to use this modified one for the larger groups.