set wrote:Why haven't these gears transfered onto the ebike scene?
With helical gears you get some axial thrust because the gears are cut at an angle.
They're also a lot harder to manufacture that straight cut gears and therefore more costly.
Having said that, some motors use them. The main one I can think of is the P2a motor, which has very high quality gears.
Helical should be stronger than straight cut because you get more than one tooth engaging at any given time. They're quieter too.