Definitely helpful, we used a lot of this wisdom on our first group ride last Sat (Team-Chaos vs the Hollister Monster).
Hand signals we used (YMMV, contains lanolin):
Your standard turn and stop signals from the DMV:
- arm extended to the left = turn or lanechange left
- arm out and up = turn/lanechange right
- arm diagonally down and palm facing back = slow down/stop/back off and give me room
Hand up, doing 'hang loose' wiggle with thumb and pinkie extended = stagger formation
Hand up, index finger only = single file (useful for twisties or one-lane roads such as 236 where you don't want to crowd each other)
Hand up, repeatedly open fingers then make a fist = tighten formation (cars are making "divide and conquer" moves)
Point to object/road surface = hazard!
Point to tank = I need gas
Hold up fingers and alternate: (number of riders present) and then (number of riders missing) = we lost some riders! (thanks Joe... I do get into the zone way too easily!) Turned out our sweeper was falling behind himself, and got caught behind a couple of cars... so once I got smacked upside the head with that signal, we stopped and waited a few minutes and here he came....
We thought we'd have need of a "scatter, there's a LEO making a move to bust us" signal, but luckily we didn't need it after all.
Something else... the group leader has to be aware of things like traffic lights, stop signs, etc. Sometimes cagers will recognise a group, and let you ride thru stops
en masse, but don't take it for granted that they will... so after you get thru one, proceed slowly, do a quick headlamp count and pull off to the side if you see part of your group hung up....
Another thing that can make or break a group ride is the leader being aware of things like upcoming exits/turns or proper lane choice... getting surprised and having to do a quick duck to an exit at best will result in some pissed-off riders, and at worst a pileup. If you miss an exit... sometimes it's best to proceed to the next one and double back rather than risk an accident.
Oh yes... on solo rides you're on your own dime if you pass on double-yellow, run stop signs, etc. Do these things as part of a group ride, and the whole group has to deal with it, either because the riders behind refuse to follow suit and get hung up, or they follow and get tagged by the Man, or they follow and get creamed by a cager or fellow biker. Err on the side of caution, because essentially you're part of a big huge "vehicle" that happens to be made up of smaller ones.
(not pointing any fingers, guys... nothing here that we didn't talk about in person already either.

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