Brace is not the solution to the spur gear stripping. The problem comes from the module of the gears + small number of teeth for the second ratio (47, 48 and 49 teeth) = too fragile
After hours and hours to practice and compete with this car (this one is really fantastic if you control this problem), the solution is the one gave by Robert Piestch in this forum:
- The good alignment of the engine (it's the key solution)
- A suave engaging for the second ratio (so better that your second speed engages early)
- No gap between the second spur and your second pinion.
The great solution would be to have less fragile second ratio (more teeth, wider spur...) but it seems difficult for Mugen to find a solution.
Really a pity, this fantastic car was commercially killed because this spur problem.