Originally Posted by
yle00984
can someone help me gear my direct drive with a 13.5 brushless. what is a good spur/pinion to start with or the correct gear ratio i want to reach?
We usually use an 88 tooth spur for 13.5. From there you need to learn to calculate roll out. The formula I use is:
tire diameter x 3.14 x pinion / spur
A good place to start 13.5 roll out is around 63mm, but it depends on the size of the track what your final roll out should be.
For a detailed, if somewhat lengthy, explanation of roll out look up Scottrick's excellent post #27638 on this thread
