Changing to from 8 inch to 10 inch only heightens the road base by one inch. 🙂
Tires have speed ratings. Cheap tires are often designed for a maximum speed of 40 mph or less. Just make sure your tires are up to the job by checking their maximum speed indication. Those that travel through Germany know that over there it is normal to “race” to Copenhagen at speeds in excess of 80 mph. You need trailer tires fit for that kind of speed and, unlike car tires, those are not standard tires!
The (rubber) springs of the hubs of my Admiral road base have broken in less then two years. because of the this the wheels, seen from the rear, pointed inward at the top and I suffered heavy wear on the inside of the tire treads.
My local trailer specialist explained that the springs were far to light for the job. A wayfarer with all its gear and some extra camping equipment weighs easily 300+ kg. Due to G-forces this weight may double under circumstances and in a tight corner much of the weight is transferred to one hub only. (In the extreme case one of the wheels lifts of the road). He advised new hubs that can handle 300 kg each. (Static the trailer can now carry 600 kg). Unfortunately these type of hubs have a different construction. They are, like with a car, inside the wheels and require a different wheel type with a minimum diameter of 12 inch. So, next to two new hubs I also needed to buy three new wheels.
Further more my trailer specialist mentioned that all the materials used by Admiral were very light and only just met CE requirements. His literal words were “They used the cheapest stuff they could find”. The main beam, to which the hubs are attached, turned out to be bent causing a misalignment of the wheels. Any misalignment will cause heavy wear and heat. It may even cause a tire to blow. Before re-aligning the wheels he welded a strip to the beam to stiffen it. The repairs set me back another 400 Euro and that for an almost new trailer. (Almost the price of a new road base).
With the 12 inch wheels I have no trouble getting the trolley on or off the road base provided it is hitched on to the car. It is only 2 inch higher then an 8 inch wheeled trailer. I can leave the trolley wheels on their axles, something most 8 inch wheeled designs can’t. And finally the speeds at which I travel over the German “Autobahn” have become a non-issue.