Two things. It just bugs me to see all the assumptions about riveted boats, by folks who obviously don't own, or have a lot of experience with them. Contrary to popular belief, they aren't just a time bomb waiting to start leaking. We have had boats from the mid 50s, that have gotten used, and abused, that are still watertight. Also had a welded one that leaked. There is nothing wrong with welded boats, except when it comes to replacing a transom :x , but there also is nothing wrong with riveted ones.
Also, what makes you think 12 inch tires distribute the weight better? Changing the tire size is a big improvement, but absolutely not weight wise. Changing the tire size, helps only the bearings. The boat, and trailer will not notice a difference. Larger tires spin fewer times in a given distance, than would smaller ones. That is due to the larger circumference. But, spinning less times also means spinning slower. Both of these help the bearings a lot. Puts a lot less distance around the spindle on them, and in bearings, distance is friction, friction is heat, and heat is bad.
I don't know if it has been said, but add bearing buddies. Best thing you can do to a boat trailer.
Also, what makes you think 12 inch tires distribute the weight better? Changing the tire size is a big improvement, but absolutely not weight wise. Changing the tire size, helps only the bearings. The boat, and trailer will not notice a difference. Larger tires spin fewer times in a given distance, than would smaller ones. That is due to the larger circumference. But, spinning less times also means spinning slower. Both of these help the bearings a lot. Puts a lot less distance around the spindle on them, and in bearings, distance is friction, friction is heat, and heat is bad.
I don't know if it has been said, but add bearing buddies. Best thing you can do to a boat trailer.