Not that I think carrying an extra magnet is a terrible idea, but how many times have you lost one?
I think that controller is monitoring the bike's speed for way more than just the throttle. It's basing a lot of it's PAS related calls to how fast the bike is moving for instance....
Start-from-zero also applies to pedal assist, not just throttle... but yeah, the speedo data is used for a lot more than just preventing accidental starts at 0.
In the Torque tab (on adjustable, UART controllers) the speedo data is used to determine which of the pedal assist's Spd0\20\40\60\80\100 ranges you're running in.
Even so, 2 or more magnets doesn't seem to help the speedo's accuracy much at all; just reduces delay getting first reading, slightly...
Since I'd need a PC (or an Eggrider) to adjust the number of magnets used, switching from 2 magnets to 1, would not be trivially easy if I lost one on a trail.
I seem to replace a spoke every month or two; just had to replace one on the AM1000 (v5). I would
not want to lose the spoke with the magnet, with no spare on hand!
Losing the speedo magnet is a relatively minor worry, but an exceedingly easy problem to prevent; spares magnets are cheap & virtually insignificant to carry - potentially even handy for other uses?
On the subject of tuning, I found it
essential to fine-tune the settings under each Spd range in the Torque tab: Prior to doing that, harder pedaling was needed, around 12 & 18 MPH.
So, two questions:
(We're on 40-tooth chainring, 42-to-11-tooth cassette) Could someone with a drastically different gearset, report which values work best for them?
For people with an m620 which
doesn't let you fine-tune the controller, does the pedal assist's torque sensing feel smooth & proportionate to your pedal effort? Either way, what gearset are
you using?