Timescales (in the source frame) relevant for the shear acceleration process as a function of the particle Lorentz factor for knot A. Solid lines show the acceleration (red) and escape (light blue) timescales. The darker blue curves show the cooling times for the synchrotron (dashed), IC on the synchrotron photons (dotted), and the IC CMB model (long-dashed). The vertical dashed orange line shows the Lorentz factor above which the mean free path exceeds the width of the shear layer, halting the acceleration process. The horizontal dashed green line indicates the light-crossing time of the shear layer.