Tire change gear ratio

[speedwaydesign]

Could someone give me a formula for a final gear ratio with the increase in >R.R tire circumference. I have a ratio now
of 4.0 - 34 inch tire. Moving to a Burris treaded 37 inch.

 

[TiBeu]

Ratio

Could someone give me a formula for a final gear ratio with the increase in >R.R tire circumference. I have a ratio now
of 4.0 - 34 inch tire. Moving to a Burris treaded 37 inch.

This is what I'd do: 4.0 multiplied by 37 and divided by 34= 4.353

 

[speedwaydesign]

This is what I'd do: 4.0 multiplied by 37 and divided by 34= 4.353

Thanks I will try your logic on this one. Tom

 

[alvin l nunley]

This is what I'd do: 4.0 multiplied by 37 and divided by 34= 4.353

I have a spreadsheet and it agrees with you. Yours is much simpler to use, but mine is more accurate, only because it tells you exactly what gear you can use.

For example; 15/60 = 4.0
Going from a 34" tire to a 37" tire would call for 5 more teeth on the axle, or, 4.33 ratio. This means your formula is very close.

I'd say this means your method is close to accurate, honestly, I think, close enough, and it doesn't require a computer and the Excel spreadsheet.

One thing; my spreadsheet can also do jackshaft ratio conversions for different tire sizes. I would imagine you have a formula for that too?

 

[speedwaydesign]

I appreciate your help Al.