tony.latham wrote:Small tires ride rougher on rough roads. They drop farther into washboards and other divots. It's a matter of geometry.
That ^^
Bigger tires bridge bigger gaps, smooth out bumps by changing the angle of incidence, smooth out bumps by having more sidewall (assuming reasonable wheel diameter), and reduced rotational speed at the hub/spindle/brakes.
Two downsides are:
-More unsprung weight and more rotational mass. This can be harder on the suspension and brakes.
-You need bigger fenders or wheel wells. For some designs, that means intruding upon cabin space.
I've been stuck in materials and set-back hell for two years on my own plans. But some of what I do have ready to go are 4 "all weather" radials (Cooper Cobra) that are
balanced and of decent size. They're 215-70R14s, IIRC. On Oldsmobile 442 wheels, of all things. -- Actually, the tires and wheels off of the Nova in my avatar.
In my case, I am combining that with Timbren axleless suspension. My trailer is intended for off road use. Not extreme use, like rock crawling trailers. But plenty of rough roads, and sometimes miles and miles deep into the back country. My two favorite places to go require 25 and 38 miles of "jeep trail" after you get off of the "main" dirt roads, respectively. Small tired trailers have a hard time on those roads, especially with straight axles under them. But with larger diameter, more sidewall, and no axle beam, it should be a much better life for the trailer.
Most of the miles will be on the highway, where lower bearing rotation speed will be nice. But all of the destinations are off road. Or, at the very least,
miles down rough dirt roads.
Bigger tires = smoother ride and a happier trailer.