Originally Posted by BigDogRacing

Wrong. The correct statement would be -all MOLDED spur gears aren't perfectly round-

Machined gears like PRS and Xray spurs are within acceptable tolerances of being perfectly round.

Also keep in mind you can have a slightly bent layshaft, motor shaft, or pinion gear that isn't cut dead center. Some pinions out there are very cheaply made....

BTW- not bustin your ballz, just sharing a little knowledge and havin fun.