I have gone through my second set of ST's. Total mileage on the trailer is about 34,000. Trailer is 40ft, 18k lbs and triple axle. The original Towmax tires were shot around 16,000 miles. Failures 2 and 3 happened within 50 miles of each other. Only 1 of the original 6 tires appeared serviceable at that time. I installed a set of Maxxis ST's. At 23,000 miles, I noticed a huge lump on the inside of one tire. Another tire had picked up some road debris and had a slow leak that could not be patched. I opted to begin a transition to Michelin LT's and installed 2. Around 25,500 miles, another Maxxis developed a slow leak. That same day, a piece of road debris cut the rubber stem on my spare, necessitating another tire stop. (All other wheels had steel stems.) We got home without a spare and I opted to complete my transition to Michelin LT's before we headed out on another major trip. Two of the Maxxis tires appeared to still have service life. They are presently laying in my garage until I get around to selling them. All tires on the trailer including spare are now LT's with steel stems. I'm at roughly 34,000 miles with no problems or visible signs of wear. For the record, I have always run a TST tpms system. It caught 4 of my 5 tire failures while rolling. The first failure was a 'full shrapnel' blowout. I heard a bang, saw pieces of rubber flying in my mirror, and then heard the alarm. The other 4 failures gave me a low pressure alarm that let me get off the road before I went flat, and also avoided possible trailer damage, so I am sold on the tpms. I am also sold on running LT's. They are rated above my axle rating. YMMV.
