‘Hall Sensor’ wires - why bother?

[T03Y]

Hi All, I’ve been messing about with kit builds the last year or so. All rear drives and a mix of new and S/H stuff. Lots of fun. Most of my troubles have been making or using wiring connectors that aren’t too stiff, frail or underpowered. Recently I swapped my (noisy) Voilamart 1500w for a ‘Crystalyte’ brand motor/wheel. When confronted with a new set of wiring problems I read somewhere that the Hall Sensor (5 fine) wires from the motor might simply be ignored. I tried it and it’s working fine. Maybe a tad jolty off the start but no real issues. I’m just wondering for future- what are they for and why does my bike work ok without them? Thanks

 

[Deleted member 4845]

You have already discovered this, they are meant to avoid "jolty" starts. That is it. Most bikes will function just fine without them.

Some controllers will NOT function in "sensorless" mode, and many geared hubs will not work well this way. But a DD hub, such as the two you have had, usually will handle it just fine. Recommendation is to get rolling first before applying throttle, which is a good idea for an ebike anyway.

 

[JoelCW]

because when the hall wires are not used, with a sensorless controller you will discover that you suddenly have absolutely pathetically slow acceleration. your bike will eventually reach top speed, but it will take much longer. plug that hall wire connector in, and you will immediately notice a huge difference. the bike will perform as it should. brushless motors need those sensors for accelerating from from zero, (stopped/not moving). the difference is night and day. sensorless controllers, for me, are only good if your hall sensors are broken. if you cant replace them, then its a great quick solution, just be prepared to be travelling at a snails pace, off the line