Terminology
Think of your socket set. If you have a ratchet you can tighten / loosen in one direction only.
Cassettes have no ratchet , so regardless which way the wheel rotates the pedals will turn , in the analog bike world this is called a fixie. Instead of a ratchet in the sprocket the ratchet can be in the hub.
A freewheel only engages in one direction, when you are coasting With your feet on the pedals they stay still.Drive uncouple/ disengage when the rear wheel rotates.
A cassette in an electric bike with no ratchet is a potentially dangerous proposition. Good way to break your ankles.
The current 2020 runner has a 11T freewheel.The bafang can use a freewheel single speed or multi speed.
There is no internal ratchet, So a cassette is not advisable. YMMV
Thanks for clarifying -- the "ratchet" concept of a freewheel I basically already know. What I did not know is to which part of the drive train the freewheel is typically attached (or integrated into); e.g., the sprocket/cassette or the motor hub itself?
If I understand you correctly, typical ebikes equipped with shiftable gears (e.g., my
RadRunner Plus) will have a motor with the freewheel ("ratchet" mechanism)
integrated directly into the hub of the motor itself, and to which a non-freewheel ("fixie") multi-sprocket cassette is attached. By contrast, a single speed ebike such as my
RadRunner 1 has a freewheel
built into the sprocket, which in turn attaches to the motor hub. Is this correct?
If so, then as I now further understand, the Bafang true 750w motor that you linked to
has no integrated freewheel, yet which is not a problem for the
RR1 so long as I can mount the stock single speed freewheel sprocket onto the new motor hub (which as I also understand requires a special freewheel wrench, and with which lots of people seem to be having difficulties because it won't fit over the motor cable. I have seen someone on YT use a split freewheel wrench, but I have no idea where to purchase one -- perhaps I would just need to take it to a bike shop).
By contrast, if I wanted to upgrade the motor on my
RR+ I would need to purchase a 750w motor
with an integrated freewheel -- is this correct? And if so, is it even possible purchase the Bafang motor with an integrated freewheel? I believe the answer here is yes. This is a version that comes equipped not only with an integrated freewheel but also a multi-sprocket cassette (though not identical to the stock RPB cassette). I believe I have seen some YouTuber's installing this setup on their RadRovers.
Thanks a bunch for your help!