a 100 or 104 tooth spur gives you a good gearing range - the pinion will be based on track and tire sizes, brand of motor, as will it being a Open timing vs a Blinky class.
The carpet track I on yesterday I ran a 100 / 53 w/ 2.10" rear tires - w/ OPEN timing.
R/C Racing since 1985 ~ Santa Maria, CA (Central Coast)
2001-2012 - South-West Tour R/C Oval Series - R.I.P.
...will the SWT be revived? Time will tell, but we ARE returning to the VELODROME in 2016