How many gears in a Tesla? (1) Are they slow off the line? Do they need more gears to climb hills?
Lots of posts here assume that Ebike motors need to "spin up" or that hub drives are slow off the line or that one drive train is "more efficient" than another due to torque multiplication that can take advantage of faster motor speeds.
DC motor have their highest torque at 0 rpm. Torque of a DC motor is mostly proportional to physical size. It is not the case that torque multiplication is important for ebikes unless the motor is too small (for example, a typical mid drive or geared hub drive) to provide enough torque to get up a hill. Big direct drive hubs have more torque to begin with and don't need any multiplication. And since the torque is there at the lowest speeds in any DC motor, a wheel speed rpm is fine.
Direct drive hubs have advantages - smoother, quieter, easier shifting, more efficient due to no mechanical losses, possibly more reliable due to fewer moving parts, less wear and tear on the drive train, and the ability to regenerate the battery (slightly) while riding. Mid drives have advantages - cheaper (do not underestimate the importance of this to manufacturers making design choices for their products), lighter, better front to back balance for going over big bumps (mountain bikes need mid drive) and no drag (albeit slight) from the motor when not pedalling.
And don't forget that a lot of the "feel" of an ebike is due to the controller systems that feed the motor juice and how they respond to pedalling, etc.
Teslas do have gear reduction in front of the one speed drive. But that is because a direct drive would require a physically huge motor to push a car without gear reduction, not because it would not work. E bikes can use direct drive with a reasonably sized hub motor.
Remember the 1 speed Tesla and just how fast it is before you buy the intuitively appealing but false argument that "torque multiplication" is important on a properly designed ebike and, in particular, that mid drives have an advantage over bigger hub drives in this regard.
Lots of posts here assume that Ebike motors need to "spin up" or that hub drives are slow off the line or that one drive train is "more efficient" than another due to torque multiplication that can take advantage of faster motor speeds.
DC motor have their highest torque at 0 rpm. Torque of a DC motor is mostly proportional to physical size. It is not the case that torque multiplication is important for ebikes unless the motor is too small (for example, a typical mid drive or geared hub drive) to provide enough torque to get up a hill. Big direct drive hubs have more torque to begin with and don't need any multiplication. And since the torque is there at the lowest speeds in any DC motor, a wheel speed rpm is fine.
Direct drive hubs have advantages - smoother, quieter, easier shifting, more efficient due to no mechanical losses, possibly more reliable due to fewer moving parts, less wear and tear on the drive train, and the ability to regenerate the battery (slightly) while riding. Mid drives have advantages - cheaper (do not underestimate the importance of this to manufacturers making design choices for their products), lighter, better front to back balance for going over big bumps (mountain bikes need mid drive) and no drag (albeit slight) from the motor when not pedalling.
And don't forget that a lot of the "feel" of an ebike is due to the controller systems that feed the motor juice and how they respond to pedalling, etc.
Teslas do have gear reduction in front of the one speed drive. But that is because a direct drive would require a physically huge motor to push a car without gear reduction, not because it would not work. E bikes can use direct drive with a reasonably sized hub motor.
Remember the 1 speed Tesla and just how fast it is before you buy the intuitively appealing but false argument that "torque multiplication" is important on a properly designed ebike and, in particular, that mid drives have an advantage over bigger hub drives in this regard.
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