I have checked on filling my grinder tires with foam. , and decided against it.
1. Filling with foam is quite expensive. I do not remember the cost, but I was shocked at the cost to fill all six of my tires.
2. Filling with foam adds a lot of weight to the operating weight of the machine. I was worried about leaving ruts in lawns with the extra weight.
3. You can pretty much count the wheels as junk, when the filled tires need replaced. Cleaning off the wheels for reuse is not practical in most cases.
With all that being said, I am stll thinking about at least filling the inside duals on my 4012. I hate dealing with flats on those inside tires.
Jeff