I am interested to hear what the standard measurements are. I see that people mention a 28 and 21 mil spacer. Thinking back on what I saw when I had it apart today that seems possible. But on the 21 mil side the "rivets" on the disc miss the fork by a fraction of a millimetre, in fact one just nicks it I think. Basically the wheel seems to be about 1 to 2 millimetre offset to the 21 mil spacer side. Any idea why this would be or if its normal (please bear in mind that this is my first bike and the first one I'm stripping so don't assume I know the basics) thanks

Longer spacer on the right, axle feeding in from left, clearance on both sides of 3-4 mm between fork leg and rotor rivets. Right and left reference to siting on bike.

Great - thanks