Microshift recently announced/released an updated shifter and wider range cassette to be used with original Advent 9-speed derailleur. It has an 11-46 cassette, which is a 4 tooth increase on the bailout gear.
I had been considering jumping to the Advent-X 10 speed set up with its 11-48 cassette but this will allow me to keep my derailleur (the most expensive piece of the puzzle).
I don’t love the steps in the Microshift cassette but I do like the Box 11-46 9-speed cassette. But I really really like the Box 11-50 cassette.
Has anyone used the Advent 9-speed derailleur with a 50T bail out gear?
Honestly, why not just go all in and get the 1×11 Shimano Deore M5100 drivetrain with 11-51 cassette. You can get the 4 piece Deore M5100 drivetrain (shifter, derailler, 11-51 cassette, chain) for $165 on ebay. The Deore M5100 won’t cost much more but will likely be better in almost every way.