axles and tire size

[Kaz]

When choosing an axle does the unsprung weight of tier size play a role. Is there a difference say between 13" vs 15". Will this be a consideration I should calculate into axle weight and spring rate.

[KCStudly]

Generally speaking, no (IMO). Since trailers in our general range of load capacity can have such a wide range between loaded and unloaded weights, it should not usually be a factor.

Now, if you had a really light weight axle (say 1k lbs with little balloon tires) and you wanted to put big 40 inch mudders on it to go race thru some outback washboard roads, you might want to rethink things.

I went with a 3k lb. axle and 31 inch AT's on 15 inch aluminum wheels using Jeep YJ rear axle leave springs (about 1700 lbs capacity on a 1200 lb. weight goal). The reason for the big axle was mostly to get the big brakes and bearings for durability, on forest service roads, not load carrying capacity. I wanted to keep the same spare for both Jeep and TD.

For standard 15 inch wheels and regular tires (around 27 inch) on a 1500 - 2k lb. axle I wouldn't worry about it.

[ratrod71]

Dexter axle company says to subtract the weight of your wheels and tires from the gross vehicle weight calculation when figuring axle weight carying capacity.