I was going through my old images the other day and came across this picture of the first prototype barn door hardware I developed, five years ago. I have learned from every generation of hardware that I have worked on.
The big takeaway from this version was that METAL WHEELS ARE REALLY LOUD!!!!! I had thought metal wheels would be great, boy was I wrong. When I set this up it howled, so it was of no use in a bedroom or bathroom as you could hear it on the other side of my house.
As this was a prototype I also had some nylon wheels made, which worked much better and were quiet. This version also did not have bearings so it did not survive the number of openings and closings.
These days Viba Barn Doors & Hardware uses an industrial nylon wheel that can survive over 20,000 opening/closing cycles, and we have added soft close to the system to ensure there are no slamming sounds when the hardware closes.
So when it comes time to buy your hardware, get it from someone with experience, because my learning will save you from having a bad hardware experience.