Throttles Default to On

[Deleted member 4366]

While I was experimenting with my double throttle, i had to keep removing the bit you twist while it was switched on. I discovered that without the twistgrip in place, the motor runs at half speed, so I grabbed a magnet from a spare twistgrip and brought it to the hall sensor. When I brought one side of the magnet to either side of the hall, the motor slowed down, and when I turned the magnet over, it speeded up.

All three throttles that I opened had the same arrangement with a south facing magnet and a north facing one about an inch apart with one hard up against the hall to stop the motor, and when you rotate the throttle, the north facing one reaches the hall to give full throttle. 1 mm gap at full throttle makes a difference of about 2mph, which explains why some throttles give more power than others.

The construction of all three was from pretty thin plastic, and a good knock would break any of them. If after the break, the low throttle magnet is not against the hall, your motor will run as long as it's switched on. However, some controllers require a low throttle signal before they give power. So switching off and on will disable it.

That's why brake cut-offs are important!

 

[shemozzle999]

Good point, well made d8veh.
It is essential to make sure the throttle, either thumb or twist type, is mounted close and secure to the handle bar grip with minium gap to prevent the throttle assembly coming apart in a crash.

 

[flecc]

They do seem to vary considerably, depending on magnet strength, position and Hall sensor sensitivity. My last two have both had almost a quarter turn from closed doing nothing, with most of the action taking place on the last half of rotation. I think all Hall throttles are rather poor though d8veh, resistance control or level changing like your paralleled pot arrangement is far better.