[What's_nitro?]

Definitely a bad gear. Either it didn't get hardened (and was too soft) or it was hardened to much (and was too brittle). I own a bunch of Mike's pinions also and I have no complaints at all. Another variable that comes to mind is that most steel spurs I've seen are only half the width of a plastic spur, probably to keep weight down. But this also increases the stress on the area of the pinion that is meshing with it. With a spur being roughly half the width of the pinion, you could say that "3.5X wear" figure is more like 7X more wear on the pinion.