[Graham]

How are you measuring 'magnetic traction'?

Before we had a way of measuring magnetic effect we used a straight length of Scaley track inclined at 45°, if your car didn't roll down it failed scrutineering.

Now we have a mag effect checker which is a simple cheap digital weigh scale with a board over the top with a cutout for a block with thick shim glued on top which sits level with the top of the board.  After hitting 'tare' on the weigh scale sit the car over the block and the scale measures a minus figure in grams, we allow -25g which is what a normal SCX motor reading would give at about 1 to 1.5mm ride height.

I bought the Scaleauto testing equipment, measures gms of displacement of a digital balance. It is very accurate and easy to use. You can measure with or without motors running