Dual QS Motors and one runs "tight"

I'm running dual 3000W QS Motors wheels on the rear of my trike. In the process of programming the Kelly KLS controllers and Cycle Analyst I put the trike up on blocks so the wheels can freely rotate. I've noticed that one wheel is more difficult to turn by hand than the other and under power it seems to run tighter. It is also a bit slower in starting to rotate when throttle is applied. The wheel also makes a bit more noise that the other (like something rubbing or making contact). When I cut the throttle power to the wheels, the good one continues to freewheel while the stiff one comes to a halt much quicker. I'm 87% certain it is not the disk brakes. There is no fluid in the hydraulic system yet and I have fully loosened the emergency brake adjustment pin. I have an email in to QS Motors but thought maybe someone on ES might have some similar experience or might provide a quicker suggestion for troubleshooting the issue.

BTW, the wheels both respond and seem to by in sync when under throttle. The controllers show no error codes and I don't detect any smoking or burning or excessive heat (although the wheels only run for 1 or 2 minute bursts during testing.)

After further review...the call on the field is overturned. As I run the motors for more testing, the stiffer wheel does seem to be continually getting better which leads me to believe it is, in fact, the brand new disk brake pads that are causing the tightness. Even though they are not under any pressure from the hydraulics or the mechanical emergency cable, the pads are still fairly tight against the disk on visual inspection and attempting to slid a thin sheet of paper between the pad and the disk. I'll be keeping an eye on this but I think with a bit of wearing in on the pads the issue will disappear completely. If it doesn't continue to get better on its own, I'll remove the caliper from that wheel and determine for sure if that frees the wheel up totally.

There should be some caliper adjustment to allow clearing the rotor without wearing the rotor and pad to do it. :/

Why not remove both calipers temporarily when testing off the ground? That should result in equal freewheeling of both motors.