How can I stop the LEGO Cargo train 60052 wheels from skidding on track? I have the Cargo train 60052, it's only around a year old and lately I've found on starting it (on both straight and curved track pieces) it isn't moving, the wheels seem to skid on the tracks and I have to give it a little nudge to get it going, even then it tends to stop further down. 

I'm wondering if this is an issue with the tracks or the wheels? 

I have taken them off and tried wiping them and 'rotating' them but no luck. I have looked online but haven't found any resolution, can anyone help me? :)
Replace or reset the rubber bands on the wheels. This trick works on the 80s era trains so should work here too.