Hey all,

Just wanted to give you guys a quick class on "effective gear ratio". Effective gear ratio is your gear ratio after you've changed your tire size. I'll give you a couple of examples of this and how to calculate your effective gear ratio.

Effective gear ratio can be calculated like so: (old tire diameter / new tire diameter) x gear ratio = effective gear ratio.

Ex 1) 3.92 gear ratio with stock 33" tires replaced by 35" tires. (33 / 35) x 3.92 = 3.70 (rounded to the nearest hundredth)

Ex 2) 3.55 gear ratio with stock 31" tires replaced by 33" tires. (31 / 33) x 3.55 = 3.33 (rounded to the nearest hundredth)

Ex 3) 3.73 gear ratio with stock 32" tires replaced by 37" tires. (32 / 37) x 3.73 = 3.23 (rounded to the nearest hundredth)


You can also calculate what you would need to re-gear in order to get back to your stock gear ratio (or close to) by swapping the old and new tire sizes around.

Ex 1) (35 / 33) x 3.92 = 4.16 (rounded to the nearest hundredth)

Ex 2) (33 / 31) x 3.55 = 3.78 (rounded to the nearest hundredth)

Ex 3) (37 / 32) x 3.73 = 4.31 (rounded to the nearest hundredth)


Hope this has been helpful and didn't confuse anyone too much.