Buzzing - Mine was making a buzzing noise at lower rpm / lower speeds. So in my neighborhood, I would turn my head and it sounded like the license plate. I took some rubbery / foamy strips that I just happened to have and cut them to size and placed them on the back side of the plate where it would first touch the humps on the license plate holder. It stopped that rattle noise. But now there's another. Sounds like it is up front and not nearly as loud and annoying.
Speedo Marks - The gear marks on the speedo are suggested max speed per gear, with the stock gearing. It appears Honda made an effort to put those marks at such spots to yield the best possible acceleration of the bike. For example, it could rev on past those marks in each gear, but the hp / tq is dropping off past those spots and eventually the valves would float and lose a lot of power. Based on the hp/tq curve I saw on a youtube video of a Rebel on a dyno, it appears to stay in an rpm zone that has the most "area under the curve," the best place to shift is at those marks. Kudos to Honda for giving us those marks.
Sound of the Bike - Last thing, last night I was driving mine. And exactly at 60 mph (~7,000 rpm), the sound of the engine and exhaust sounded almost identical to something else I've heard. So as I was riding, I was thinking, "what is it, it sounds like?" Was it my lawnmower? No. Weedeater? No. My 3rd Gen RX-7? No. My truck? No. I couldn't figure out what it sounded like so I decided to just forget about it. Right after I decided to forget about it, a bell went off in my head, DING! It sounds almost exactly identical to my leaf blower! Other speeds it doesn't. But at 60 mph, it was uncanny how it sounded just like the leaf blower! I chuckled and enjoyed the rest of the ride.
2016 Honda Rebel 250 - The "Piglet."
Totally Stock at the moment.
Bought on 6/29/19 with 44 miles.