[Caniel]

I read some where that trailer tires need to be exercised. Some thing about compounds that keep the tire supple and something else (can't remember at moment) need tire movement to work. (I'll have to look for the reference.)

I understand the worst thing one can do to a trailer (ST) tire is to let it sit with weight on it. If it is going to sit for long periods of time, I'd suggest jacking the trailer up to take the load off the tires. Naturally it would need to be properly supported for storage.