Help with math on larger tires...

[guitarjesus]

Tell me I'm crazy someone, but if I increase the size of the tires on my boat trailer by 2", I'm only increasing the size by 1" above the centerline of the hub right? I'm putting larger wheels and tires on my boat trailer and need to raise the trailer fender/step to do so.

So by putting a 1.25" block under each side of the step, I should be good, since half of the increase in size is also on the lower half of the tire.

Am I wrong in that line of thinking?

 

[HSKR R/T]

Tell me I'm crazy someone, but if I increase the size of the tires on my boat trailer by 2", I'm only increasing the size by 1" above the centerline of the hub right? I'm putting larger wheels and tires on my boat trailer and need to raise the trailer fender/step to do so.

So by putting a 1.25" block under each side of the step, I should be good, since half of the increase in size is also on the lower half of the tire.

Am I wrong in that line of thinking?

You are correct. 2" taller tire is only 1" taller sidewall

 

[guitarjesus]

You are correct. 2" taller tire is only 1" taller sidewall

Perfect. Going from a 13" wheel to a 15" so I can get a bigger load range, higher speed rating, and add brakes to the trailer.