[hat_man]

I have contemplated a rear gear change and know that I will have to change the speedo gear on the end of the speedo cable to compensate. But I was also exploring the option of new tires for the future and may have to go up a size from 14's to 15's.

So here is my question...is there a "calculator" or formula here to input tire size and rear gearing to get a final drive ratio?

What I am thinking is if I swap from a 3:73 rear gear to a 3:45 I'll change the speedo gear accordingly. But if I also add 15" tires to the equation this would effectively lower my final drive ratio, so for example, could I go 3:45 rear gear and 15" tires but swap for a 3:31 speedo gear (or any other speedo gear) to get it all to even out in the end? And if swapping for an all together different speedo gear would work, how would I "do the math" to find out which one?

It's too many numbers to wrap my head around at this point, but I think you can see what I am getting at.

Thanks for the help!