Your spur wears the fastest???
![Shocked :shock:](./images/smilies/icon_eek.gif)
You must fit the gears too tight!! In my opinion gears in M18 are just perfect!
Perhaps you should ask this question on the M18 forum rather than on general...
I had driven a 300 motor for some time, then I switched to brushless Mamba 5400, I drive the model a lot and see NO WEAR OF SPUR GEAR AT ALL. Even the pinions are very durable given they`re plastic... With high reving brushless motor I have recently started to use 15 T titanium pinion from Micro RS 4 - now the drivetrain is just perfect.
Some M18 owners use Mamba 8000 kV brushless motor (a model equipped with this motor and a 4 cell li-po battery can reach some 100 mph) and I haven`t heard them complaining about the gears - some of them did not even switch factory bevel diffs to ball diffs!!!
In my opinion there`s no need to produce any metal gears (they would only increase the total weight of the model, and the rotating mass in particular), except for the pins.