Originally Posted by Persistent
Dexter Axles are de-rated by 20% when two are used in tandem. Are you saying the tires on those tandem axles are not de-rated?
Correct. Dexter likely derates axles for tandums because they place loads on each other via the center pivot when going over uneven ground, pot holes, etc.
Tire load rating gets derated when they are in a dually config (like on a F350 Dually rear axle) because they run hotter, things like the heat of the brakes gets transferred to the tires more (inner dually rim is cup shaped and surrounds the brake) plus less airflow between tires.
Single tires on tandum axles, like most travel trailers, each tire is "alone", doesn't wrap around the brake, and gets full airflow on both sides of the tire.
Of course you shouldn't exceed the which ever load rating is lower (axle or tire).
Even LT tires are derated for duals.