This is the right diameter for my 48T chainring, But the wrong bolt pattern, 5 bolts, I need 4. Look on E-bay, You will probably find one that works for you if this doesn't. Changing the chainrings with one with a cover, Which might require replacing the entire crankset, Which has to be compatible with the bottom bracket, Or you will need that too would not even be an option for me. I would miss to many re-run's of Star Trek.
https://www.amazon.ca/BEESCLOVER-Mou...gateway&sr=8-2