Tandem trailer fo FX21
Front starboard tire wearing bad on inside.
All others look great.
Problem?

Besides correct tire pressure, here's some things you can check that will cause inside wear.

1. You may be experiencing some wear in the suspension components that can cause tire wear and also be a symptom or cause the axle to be misaligned. Inspect your suspension components and if any of the holes where hardware goes is egg-shaped, that indicates wear.

2. To determine if the axle is not properly aligned, pull in straight on a level surface and stop. Measure from the center of the axle on one end to the center of the ball hole on the coupler. Then do the same on the other side. Even a small difference can cause wear.

3. Tire wear on the inside generally indicates an overloaded trailer. If you have not been carrying heavy loads, check to see if the axle has been flipped. If it has, that would be why the tires are wearing. An axle has a bow in it that should be curved up. When a load is placed on it, the bow helps support some of the weight, the axle straightens some and the tires will wear evenly.

4. If you can jack up one side of the trailer, try moving the wheel alternating pushing on the top and bottom of the tire back and forth. If there is movement, this would indicate there is a bearing problem and you will need to replace the bearings, races, and seals.

When I had this same issue a couple of years ago with a 2018 FX21 I found that the bow post on the trailer had loosened and was pushed up all the way forward due to power loading which caused too much weight forward on the trailer. After placing it back into the original position the tire wear problem was solved.

Thanks guys. Seems strange That it’s only one of the four tires.
I’ll check what’s been suggested.
It’s a 2014 FX 21