There is a really big Michelin tire facility near the airport which is closest to me in Hudson, CO. This tire facility is not a retail outlet, but a part of the company's manufacturing operations. I visited the supervisor there to see if there is a way to beef up the wheel barrow tire on my Max so that it is more resistant to punctures and flats caused by thorns.

After some experimenting, he suggested I could use one more tube lining between the tire and the inflated tube to add thickness and some strength too. The additional tube lining should be from same size tube that we use ( for lining, you could use discarded tubes which have had flats in the past,) with only a narrow strip removed along the inner wall where it contacts the wheel rim - that is by cutting off a narrow strip along the inside edge, (cut away only a 1 inch width on either side of the old nozzle.)

Keeping most of the spare tube intact for the lining, does two things. First, the extra tube will stay in position and not slip around inside. Second, it adds some strength to the stock tire's weak side walls, besides of course, adding to tire thickness along contact path on ground.

I tried it and found it to be an improvement. It is not as heavy as my example in picture up-thread on this page, it adds a little strength to side walls ( a wee bit, but it does ), and it is as supple as before, so the shock absorption capability is still retained.

Thought this might be of interest to those who seek some salvation from the poor quality of stock wheel barrow tires.