There are a series of basic rules to follow in order to ride properly in a group, and yet it is often surprising how few people know these rules.
You might think this doesn't apply to you; after all, you are a Cat. 1 and winner of the Thursday night or Saturday morning World Championships...so like I said, it's amazing how many people don't know how to ride in a group. If you are new to the sport, this will help for your next group ride, if you are old to the sport, this should be a useful recap of what you already know.
Rule 1: It's Not a Race
A group ride is NOT a race. You are not to "attack" off the front or try to show everyone how strong you are. That's what races are for.
Rule 2: Bar-to-Bar
This is probably the most important rule. Whenever riding in a group, you should be riding two by two, side by side (with only a few centimeters between you, you should not be able to fit a bus between you and rider beside you) and be perfectly handlebar to handlebar.
Do not at any time sprint ahead and disrupt the flow. Even if there is a corner coming up, stay side by side and go through the corner like a well-oiled machine. Riding with your bars ahead of the rider beside you is called "half-wheeling" and is a major faux pas.
It's up to you to keep up with the speed of the slower rider next to you. And for goodness sake, please try to keep to the side of the road, there is no need to take over the whole lane and annoy car drivers.
As with everything, there is an exception to the rule. If there is an uneven number of riders in the group and you don't have anyone to ride alongside, you should place yourself in between the two riders ahead of you, with your front wheel between their two rear wheels.
This allows the riders behind you to remain bar to bar and to keep the group tightly together. The riders behind you should ride with their front wheels on either side of your rear wheel. It's not acceptable to sit directly behind the rider ahead of you and leave a gap to your side.
Now, before you spark up and say that riding between the wheels of the riders preceding you is unsafe, let me point out that if everyone is riding bar to bar as they should be, you are guaranteed the space of a handlebar's width within which to move, which should be ample. So even if the two riders ahead of you knock into each other, you should have plenty of space. This is a pretty safe place to be.
Rule 3: Peeling Off
When you are tired of riding at the front and you feel it is time for you to go to the back, make sure the rider beside you knows you are tired and want to go back. Once you have both established that you are going back, check briefly that there isn't someone overlapping your back wheel, then both riders slowly and gradually move to the outside and let the group come through the middle. Do not suddenly veer off to the side; peel off in a steady and controlled manner.
Rule 4: Pulling Through
When the two riders ahead of you peel off, it is your job to come through to the front and pull the group along. If you do not want to ride at the front because you are tired or less fit than the rest of the group, it's too late to avoid it now. Once you are in second wheel, you must come through to the front.