Originally Posted by
fyrstormer
The "gold-colored" crank pin is probably narrower because it's Titanium-Nitride coated, so it won't wear down as much, so it doesn't need to be wider to start with to compensate for wear over the life of the engine.
I don't know for sure if that information is correct. I had to remove the coating layer when replacing the bearings and installing a coated crank instead of a non-coated crank. It just didn't fit.