The particles are binding to the object, there is no speed?

[MonosP]

Object Bind works on particle positions, not necessarily velocity depending on the bind mode.

To derive velocity from position changes, add a speed operator, and set both magnitude/direction modes to "verlet". If you need continual updates, set timing to continuous.

Nice, thanks for this, I'd been struggling with how to define a velocity threshold over which particles bound to an actors surface would detach and this sorted it.