pic: 2605 Mecanum Drive

[Ether]

Originally Posted by Mr. Lim

It's hard to see, but when the robot sprints straight forwards or backwards, the wheels are spinning faster than the robot is moving.

It looks like the wheels are just losing traction on the floor.

Normal mec behavior in the forward/reverse direction is for the wheels to turn at the same rate as the vehicle. Without losing traction, roller free play and floor compliance will cause some deviation from this, but not to the extent shown in the video.