Accreting black holes are observed to launch relativistic, collimated jets of matter and radiation. These sources come in a range of morphologies and structures, and it is important to try and understand the underlying physical processes responsible for the dramatic differences between jets. In this work, we examine the role of mass accretion as probed via X-ray luminosity and its connection to jet properties, in particular jet knot velocities. We find a positive correlation between the mass-scaled X-ray luminosity and jet knot velocity. In addition, we find evidence that the jet velocity is also a function of viewing angle, supporting the "spine-sheath" model of jet production. Our results reveal a fundamental aspect of how accretion shapes mechanical feedback from black holes into their host environments.