Why does my back tyre wear so much more quickly than the front? Identical tyres, identical rims, minimal braking on the back wheel, no skids, properly inflated at least once a fortnight to manufacturer's recommended pressure.

Why does the back one wear out more quickerly than the front?
Kerry Irons put together an impressive breakdown of tire wear data.

His read on it is the fact that the rear tire is the primary driving force and thus the main point of power dissipation is the reason for the increased wear:


  Force per unit area grinds off the rubber, so higher rider power and lower contact area increase the rate of wear. 


This makes more sense than the weight ratio, when you consider the weight distribution is perhaps 20% higher on the rear while the ratio of wear is significantly larger.