Originally Posted by Corse-R

Is not a matter of material wear, is purely a matter of fatigue of materials, after a break-in, the bronze bushing and the aluminium that surrounds the crank pin and the piston pin could be fatigued with micro cracks that can ruin the engine if the material fails.

On a .12 haven't found a conrod (if the engine has had a correct maintenance) that bronze bushing has been worn and needs to be changed. But sometimes sh*t happens and the conrod you saw in perfect shape, shits himself at the backstraight at full throttle and nothing is more scary that hearing your engine and thinking you were deaf suddenly because you don't hear the sound.