What the smallest rubber wheels that can be turned by a Technic axle?

This is what I have so far

[![enter image description here](https://i.stack.imgur.com/PS8rU.png)](https://i.stack.imgur.com/PS8rU.png)

[Wheel Full Rubber Balloon with Axle hole #4288](https://www.bricklink.com/v2/catalog/catalogitem.page?P=4288#T=S&C=11&O)

Background: I'm building a GBC and I want to push the balls at speed across an open area. I plan to hide small spinning wheels in the opening they go through and assume that rubber tyres are the best solution.