Talk N' Action Thomas Incline Problem

[Super]

At first thought I had agreed with AOF but you said in the video's description that you changed the tires. The tires in the video look like they don't sit proud enough from the plastic of the wheel where it wouldn't have enough grip on the slope. Did you use a new rubber or just ones from another train? My second thought was that in addition to the tires, the slope needed a good washing to restore the traction but I think you said this particular engine slips on all slopes. The engine looks very strong and probably not any gear slippage, looks like its entirely within those wheels. I would be curious if swapping out the axles and wheels of one of the other engines would narrow down the investigation.