Laughed at this as pretty accurate to my experience; added some additional caveats.Here we nod. But there are unwritten rules.
1. You no't nod at scooter riders.
2. You nod at Harley riders (Because they could be criminals and you might need their help one day), but don't expect one back.
3. You don't nod at a 3 wheeler, unless they nod 1st.
4. You only not at police when you want to get pulled over.
5. If a little kid looks at you, you nod and rev your engine.
I love these ahahaLaughed at this as pretty accurate to my experience; added some additional caveats.
1. Scooter riders seem oblivious to motorcycles; they never wave/acknowledge me. I stopped waving.
2. Harley riders I wave and maybe get 30% waves back.
3. 3 wheelers I rarely see, but not really on my nod list; two wheels is uniquely different (balancing/leaning, etc.)
4. I don't wave to police, but mostly because it's too hard to know how it'll be received.
5. If kids notice me I always rev bomb; parents seem hit or miss on appreciating it.
6. I always wave to construction / people holding the stop signs at construction sights.
7. I don't wave to bicyclists; they only seem to wave/acknowledge their own breed (and there are a ton of them).
8. I am hesitant to wave to those without gear / helmets, but like Harley riders, I do it anyway (unconditional).
9. I wave to people on the other side of a median if it seems applicable, or at stopped intersections diagonally.
10. I tend to wave going through a turn if I get into the line of sight of another rider.
11. I don't normally wave to someone that I am passing by, unless I'm slowing down to a stop but passing them in another lane.
12. I always wave to cars that wait for me to pass them before pulling out of a side street (and I know no one is behind me). It's not that I feel bad for making them wait, it's that I'm appreciating that they are sensitive/considerate to me (and potentially unsure of my speed to make an accurate decision to pull out safely in front of me). I figure humanizing myself will help them continue that defensive driver/safety mentality, which could save my life.
My wave to riders is typically thumb up, two fingers out, mostly extended arm at 7-8 o'clock and sometimes I exaggerate the wave with a smooth body/head lean leading into it (I saw an old guy do this and it fulfilled me greatly). I might change this, but typically I like to sort of have my own branded wave/persona in case I see repeat riders.
When there are obstacles, I'm doing #12 above, or I'm not in a comfortable position to do the default wave, I'll do a piece sign/steady hand palm facing them above my handlebars. If I'm coming off a stop sign and someone lets me through I head nod since I'm typically still feathering the clutch when the reasonable time to acknowledge them passes by.
Lastly, I use my head to both encourage people, mainly pedestrians or other cars, to take the right of way (which they have when I do it; but sometimes people are unsure/defer to the motorcycle so they break the regular "rules"). This head movement also comes in handy when I am changing lanes; I signal first, head nod to both look + additionally signal interest (so I'm predicable), then I head nod at least one more time, then I make the move (if safe to do so).