checked the gears again, they're fine and still greased up well.
One thing I've noticed with 3 gear assembly is that it is not fixed in position with relation to the ring gear. In other words, it can wobble around and therefore no longer mesh with the ring gear on the same parallel plane. If that makes sense. One would hope, that when the motor is bolted together that everything is held in place nice and straight and tight, but there may be wiggle room to go out of alignment, who knows...
I've made three youtube videos. The first shows the motor only (no gears or freewheel mechanism) in my dropouts. Hubmotor case/wheel and gears can be seen in the background. First I throttle up the motor at ~40v, this consumes 24W and registers as 33.3 kph on the cycle analyst. Using the 1666mm wheel diameter trick programed into the CA (which outputs speed in kph as 10s of RPMs) that gives an 1100-1110 RPM wide open throttle (WOT). Then in the same clip, I add a second pack in parallel for ~80W. It shows 75W power, 65.7kph, and 2210-2220 RPM. In both cases the motor sounds quite nice and smooth to me. With no mechanical reduction this is the best (quietest) the bafang will sound like:
High Quality here: http://www.youtube.com/watch?v=6fdxLmGQGEU&fmt=18
Ok, next up 40v in the wheel. First I throttle up and then down very slowly and smoothly. Then I go straight to WOT and dump it back to zero. Listen to the mechanical sounding clunking. I suggest you stop the video at 1:55. My girlfriend suggests it's blindingly boring to watch
you may agree:
High Quality here: http://www.youtube.com/watch?v=V3yQi2DxZq0&fmt=18
Lastly, 80v in the wheel. Same tests as above.
High Quality here: http://www.youtube.com/watch?v=mwTkL1QPM9I&fmt=18
Although the wheel wobbles a bit in the video, it's extremely close to dead true. I had a bike shop true it on their truing stand and with the bike upside down in the and looking at the rim passing through the brakes side to side and up-down movement is very very small.
I'm curious about the mechanical clunking. Gears, freewheel? I'd like the motor as quiet as possible. I'm tempted to pack it with more grease but I don't want too much slinging into the motor windings.