It has been about one month. It's a lot to wade through on page seven, and most of the verbiage is MY FAULT.
To repeat to make sure there is no error of any reader taking my assertions as truth.
I was wrong. Planetary spur gearing is perfectly efficient as any other sort of spur gearing.
But it DOES tend to make noise. So "we" gear makers, that is, have long used silent materials for gears, even rawhide was used in the nineteenth century for special applications; leather steeped in gutta percha or shellac to make it stronger yet.For a gear maker to employ NYLON, if that's what they use in Bafangs and eZee motors, etc, is absolute ignorance on parade, or OK for 12mph motors that won't be seeing any tough service, no road shocks, etc.
Nylon: cheap, quiet, soft, thermoplastic that loses even more strength as heated, it then melts at some point.
There are, another poster noted, a variety of moldable (cheap to make) gear plastics that are tough and forever. Whatever Honda uses in their one-lunger four strokes for the half time gear, is silent plastic, tough, heat proof and durable in this super-severe service
. Wham, wham, wham, as the ICE engine explosions shock the gears with every ignition.
There is no sense in using steel planets in motors of any sort.
Soft steel against soft steel (the ring) make a very poor wearing combination.
Hard steel against hard steel run in oil, like a proper auto transmission, preferably helical cut, is fine. But not soft steel running in grease, not for a long term of say, ten thousand miles. It won't/can/t wear well. And it may tend to be noisy as heck. Or quiet. Depends on the luck of the machinist. But metal against metal spur gears running at high speeds almost always are NOISE.
Nylon is the worst plastic, practically, for this sort of ebike motor service.
It is not strong enough for long use, especially under shock loads and high temperture.
But I was wrong wrong wrong
in asserting that planetary transmissions are lossy.
I was thinking, in error, of the Model T transmission. It is very lossy in "low gear",
but for different reasons than obtain in a fixed-ratio geared motor.
Eh, I'm a blowhard, but most of what I say has mostly truth to it.
Sorry for aggravating or misleading anyone reading this far. I apologize!