Tripleshot Cycling

Today was a truly glorious day and a great ride through the valleys, around the bays and over the hills.

However, things got a bit hairy and I wanted to get some clarification around protocols when one group passes another during a sprint.

When our B group (B2) was finishing our first lap of Beacon Hill, the very speedy and strong A group came around us in their sprint finish. They passed us in a nice tight line on our left, and our group (I believe) held our line on the right.

Suddenly, it seemed that our group was hitting the brakes, avoiding A riders who were sitting up, passing on all sides, etc. To put it bluntly, it was a cluster-cuss! Many of the A riders were holding their line on the left, with some soft-pedalling in the lane to the far left. But others were in the middle of the road, and some on the right, which I assume meant that after they finished the sprint, them crossed in front of (or through) the B group they'd just passed, like a car passing on the left and then turning right. Bear in mind this was in the same spot where some riders were hit last year, with the sun in our eyes and riding at breakneck speed.

Rather than try to catch up to my scattered group and finish the laps, I packed up my ball and went home, still happy with 95% of the ride, but a little disappointed with the finish.

I was towards the back of our group, and focusing on not colliding with the riders in front of me, so I didn't see what actually happened, and I'm certainly open to correction if I've got events wrong.

But I would suggest that we confirm / establish / clarify the proper protocol for this situation. It seems to me that the "right" approach should be thus:
- The faster group passes on the left, and the slower group holds its line on the right, with the passing riders indicating "stick right" or "hold your line" or "watch out!" or something;
- At the end of the sprint, the riders can sit up, but should hold their line on the left, even if it means continuing around the corner, while the other group pulls through on the right.
- And generally, any time a rider (or group) is passing another rider or group, he/she/they should be sure to let the rider(s) know they're coming and on what side.

Am I stating the obvious? Have I got it all wrong?

Yeah it was a mess, though not anyone to blame, except maybe forgetting a bunch was right behind. The narrowing of the road with the lane dividers made it worse too. I think keeping left might do it, but its a different habit than the keep right convention the rest of the time. Could work though if someone reminds the faster bunch each time.