I used the gear Darrel sent. They should be 80 degree, not 85. 82 is the acutal scale degree, but, at least on the KMP ME-109. Sierra offered the choice of either 80 or 85 degree. With the KMP I opted for the 80 degree to spread the wheels out slightly. The CMP 109 Sierra-Giant gear is supposed to be 80 degrees as far as I know.