The builders who swear by low speed-count setups are typically also swearing by 8s free
wheels and Tourney or Altus derailleurs. And they're throttlers, not cyclists. They see more expensive 10s+ setups as delicate and don't understand the 'more durable' part.
Every homemade ebike that has been successful with a nice cassette for Hills and for Flats has been a maximum of 10 speeds.
See above. This is completely wrong. Its builders only knowing a little about what they are doing and thinking because thats all they know, thats the way it is.
If you try to run a 48 or a 52 fast you will scrub those gears in no time. That's just common sense coming from a road bike world.
What? I come from that world dating back as far as the mid 1970's and nobody ever told me that or worried about it. I used a big 52T ring on the front and at times, a straight block on the back (12-18T 6 spd, and never more than a 12-21T). Now, with that said, a powerful mid drive with a big chainring is ALMOST always the wrong answer. The issue is bogging the motor, which a big chainring will do since a 1750w (30a/52v) BBSHD is not all-powerful. Also you are applying torque on a skewed chain if you are using that 52T on your 11T cog, and tripling up that error vis-a-vis minimal tooth engagement. But if you are a smart builder with the right circumstances, it can work great. Look at Post #5 and see a 52T ring on a 30a BBSHD that saw duty on flat land and had straight chainline in the middle of the 11s cluster. I never needed to shift more than 2 gears in either direction thanks to the flat land. That was the chain that lasted 4 years and 4200 miles before I changed the drivetrain to the other setup you see in the same post.
'Scrubbing gears' comes from running the chain when its skewed over. Turns the chain into a chain saw. Thats rider error, and possibly builder error depending on how bad it is. Don't blame the equipment.
As far as drivetrain, Deora all the way.. 9 or 10 speed would be in the durability longevity area. Just my two cents! Party on!
If you do 9s Deore, do the pinned-together-steel HG400 cassette. But 9s components being desirable is very 2019. Step up to 2025 and you can find steel-is-real stuff that is also inexpensive. Or drink the Kool Aid and go all Shimano Linkglide, which is 11s but you will spend double what you need to if you instead buy smart.
For me the sweet spot is 11s (and one 10s with an 11s chain). 12s you can start to see things like chains snapping. Most of this is rooted in operator error (shifting under power on singletrack) or using smaller teeth on 12s-compatible chainrings, that let the chain jump and shock the hell out of it. Even the chain jumps can be operator error (they were for me) trying to be in a gear that would be fine on an 11s with longer-toothed chainrings but on a 12s Lekkie Pro: not. A different tooth profile that fits a 12s chain would also solve that issue. But here again you need to be a builder that knows your components and the resulting chainline to pick the right stuff. 12s fails are more likely, but not failures of the platform itself.
) and figured that it is done on purpose?
