Why doesn't Bridgestone, Michelin, Hankook, or Continental make ST type tires?

I was asked by a fellow RV owner if I could recommend a tire for their trailer.

We have asked why the major tire companies other than Goodyear (Bridgestone, Michelin, Hankook, and Continental) don't carry ST tires, but they didn’t really provide a direct answer.  Just sort of danced around it.  I have been reaching out and trying to find an ST provider, but have not had any luck so far.  

My reply:  In My Opinion,

None of the "major" tire companies are interested in the RV trailer market (ST type tires) because of the documented poor level of weight and inflation management. Goodyear tire company pushed for the introduction of Special Trailer tires back in the late 60's & early 70's at a time when 20' single axle trailers pulled with bumper hitches were the norm. a 1/2 ton truck was rarely an option for average family use vehicles. ST tires were offered with increased load capacity i.e. lower cost to the RV company and to compensate for this the 65 mph max speed and reduced tread depth was presented as required and sufficient to allow the bias tires of the day to run to wear out in maybe 10 to 15,000 miles. Many times P-type passenger tires were applied to these smaller RV Trailers but a -10% load capacity adjustment to the P-Type load capacity was required.

The 1974 National 55 mph speed limit kept operating speeds down so tire failures were still at a lower level but with the introduction of steel-belted radials to the tire marked coupled with the growth of trailers to 35'+ and tire mileage theoretically increased to the 30 or 40,000-mile range the tires no longer wore out but started to fail at an unacceptably high rate.

The annual tire market in the US is 200 Million a year for Passenger type tires and about 37 Million LT type. Annual sales of all types RV is very volatile and ranges from 160,000 to 500,000 a year for all types, from Class-A down to teardrop,  Some industry information suggests only 20% of the RV market are "conventional RV Trailers so that would translate to a market of 400,000 tires in the best years  When looking at the tire market I think we can see little incentive for a company to go to the effort and expense of developing tires for a market that is only 0.5% of the P- and LT-type tire market. Especially considering the high level of warranty claims and problems due to the extremely poor maintenance record seen from RV owners.

BUT   back to the original question. The only ST tire that I was able to look at a section of recently was a Goodyear Endurance. It looked like it might perform better than some other ST tires I have looked at.  BUT  the only performance data I have is just the reports on various RV Forums where customers seem happy with the Endurance.

Sorry to say that your choice is relatively limited if you have to stay with St type tires. While Maxxis and Cooper have supporters you might be better off switching to LT type as long as you make the required adjustments for load capacity by increasing physical size and or Load Range. If you follow my blog you should have already see THIS post of the topic of lT vs St type tires..