Originally Posted by

**JT1000**
So I know gear ratio/RPM/MPH threads are all over, but wanted to see if someone could chime in and validate or correct my theory....

Running on an approx. 1/8 mile banked dirt oval. Currently geared 12/61 and topping out at 5,890RPM's. I'm wanting to get closer to 6,200 RPM's so I was doing the math to determine how many sprocket teeth to add. Here's the math:

Current gear ratio=5.08333 (12/61)

RPM=5,890

5,890/5.08333=1,158.69RPM per 1.0 gear ratio

6,200RPM/1,158.69=5.3508

5.3508x12=**64.21, or a 64T sprocket.**

I was told that an +/- 1 tooth on the rear equals +/- 200RPM's (talking 35 chain setup). My math gives closer to 97RPM's +/- 1 tooth change. What am I missing, or not factoring in? Mainly just curious and not out to prove a point or to be right. I work with numbers so it's hard to deny the math! Thanks for any input.