Roll out app and gear ratio chart

If anyone is interested there is an app in the google play store called "Nor-cal hobbies gears". You enter your pinion , crown gear and tire dia. and it will give you the gear ratio and the rollout. If you use inches it will read out inches or if you use mm it will read out mm, You can give each read a name and save it for later info. I used this when I raced onroad 1/12. 

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