Does anyone know why the gearing makes so much of a difference when it comes to larger tires? The reason that i put the question out there is because 33 only weigh an average of 8-11 pds more per tire.
Very well put, definitely makes more sense.Changing the gears in the rear end to compensate and equalize for the tires is the only way to compensate. Switching to larger diameter tires is the exact same as swapping from say, 3.73 gears for 2.73 gears; tires ARE gears.
Yes, moment of inertia makes a difference. The easiest way to see this would be if you had the rear tires off the ground and hit the gas. The heavier tires would take measurably longer to spin up. But once you introduce the resistance of the weight of the vehicle itself, the effect of moment of inertia would be a very small percentage of the change in performance. Once the tire is actually on the ground, the change in leverage due to the fact that the tire really is just a larger gear....plays a much larger role in things.If you really want to get technical, larger tires impact performance in two ways on any vehicle with wheels not just race cars and Jeeps. The first is what you are referring to impacts the final drive ratio. The other is the Mass Moment of Inertia (MMI) which affected both by increase of tire radius and the weight or mass of the tire. Braking must counter the MMI so mass of tire absolutely has an impact. Otherwise it would be just as easy to stop a 2 ton 33" tire as it would and ideal weightless tire. With all due respect tires are a lot more than gears.