Weight.So what's wrong with steel wheels?Could be sealed tubeless with black tire bead sealant.
The plastic 4" rim is half the weight of the HF steel one about that size. Tubeless tyres have an air impermeable inner layer. Trying to seal a tube tyre will need frequent reinflation. Tubeless tyres can be found in many sizes, Carlisle seem to make all their lawn ones tubeless and are a reasonable quality and cost. The HF tyres are pretty appalling...
I haven't weighed a 4.80/4.00-8 HF wheel yet, but Grainger puts the weight of a 4.80/4.00-8 wheelbarrow wheel as 6.6lb, nearly 2lb up on my plastic ones. I'll try to remember my luggage scales next time I visit HF.
My wheelbarrow wheels are 8oz heavier than rocky's BMX type wheels, not bad for all the extra tyre they have. Probably stronger, too. If tubeless tyres work, they could end up lighter than Rocky's wheels. There are numerous plastic wheelbarrow wheels made in China, I was hoping to find some that take the 1 3/8 OD bearings, but didn't. I may see if I can get some sample rims direct from China.