finishing up my hunting fat bike build. Using BBSO2. Previously used hub motors. The throttle on this seems to be merely an off on switch. Not the gradual rheostat that I’m used to. Same with pedal assist.
is this normal with these middies, or is there a problem? Programming?
I run a S02 as well, and I would say that getting the throttle to respond gradually is a matter of programming. I forget what the default setting is, but the Throttle Mode should be set to "current" for smooth operation. It might be set to "speed", which I believe can produce a go/no go response. In "current" mode, the throttle behaves more like a car's accelerator pedal.
On the flip side, the S01/S02/SHD motors use speed sensing for the pedal assist - not the more expensive torque sensing. This cannot be changed. However you can program the controller to better suit your style - but it will never behave like a torque sensor. For example, I increased the speed limit on all 9 of my assist levels - so that the motor doesn't cut out nearly as often. This provides a better experience for me.
I'm thinking of upgrading to a SHD motor, but it still has these limitations - so I'm really undecided at the moment.