Originally Posted by
mihlbach
At any rate, without fenders you are spraying the same stuff directly onto the chain, derailleurs, chainrings, pedals, and cogs, thus introducing the same abrasives to the same components, but in much greater quantities with much higher and more forceful velocities.
Actually his argument makes sense. With no fender, guck flies outward, away from the wheel; with a fender; some of it is contained and may be redirected inward towards the center of the wheel.