1. It’s not a MASSIVE amount of unsprung weight. Think back to the 60’s through 90’s vehicles with rear drive.
2. The unsprung weight is not the major problem, but is a factor due to the COOLING SYSTEM required for each hub motor. That is what has slowed down the marketability of the hub motors. Cooling system involved complexity, added cost, and added weight.
SO.. weight is a factor, but not because it drastically added to unsprung weight.
There have been advances in motor design and streamlining of the cooling system recently and that is why this article was done. The technology is ready for production on a large scale and that will reduce COSTS.
“Think back to the 60’s through 90’s vehicles with rear drive.”
Mustang went to IRS in 2015. Reduced unsprung weight over 100 pounds.