Yes. https://www.unicycle.com/commuter-36-inch-tube/Should work then...just out in the shop and noticed rust on the tires. Unicycle tube, did you say?
I only have them on when moving the carriage across concrete. I did not get them until I had rolled it across concrete a few times and did loose some paint but once I began using the tubes, no more paint loss. I could afford to re-paint to get them completely back to solid black.