People talk about "the facts", but I've yet to see them.
The "studies" I've seen were commissioned by belt manufacturers, and they were comparing new belts to debilitated chains that THEY had decided best represented the condition of "real world" chain drives. Spray salt water on a chain and belt before testing and we shouldn't be surprised if the belt wins.
If you have seen a study that compares well adjusted moto belts to well adjusted and lubed moto chains, you should share it.
I'll certainly grant that there is less maintenance with a belt. On the other hand, the chain offers:
Better durability
Higher load capacity
Easier ratio change
Substantially less expensive component replacement cost.
My study is self-funded and I have no product to push.
I ride in the rain, and I take trips that go for 2500-3000 miles, and sometimes it rains for a lot of those trips.
My bike makes a lot less HP and torque than many bikes that have belts that last a long time. And my bike weighs half of a Harley, and I will only ride one up, so the load shouldn’t be an issue.
A replacement belt will cost less than one of the two or three sets of chains and sprockets that would have worn out over the life of the belt.
My gearing is set and I see no need to change it.
I don’t care if a belt or chain is more efficient in delivering power to my rear wheel. But I do like the fact that there will not be any more chain spluge to clean, and that the belt should last 30k miles. The six sets of tires that I will go through over the life of the belt will be a less dirty job. And I don’t have to worry about adjusting while in a long trip.
For me, it’s all upside. Everyone else will have to come to their own conclusions.