I have a 3t exploro pro grx 2x which came with a 11-42 rear casette and a grx rear derailleur.
I am looking at the grx-810 specs and i see the maximum cog for the grx RD-RX810 is 34t and the RX812 is supposed to only support 1x and I have a 46/30 chaining rings
my question is what kind of derailleur do I have?
if i want to change the cassete for something lighter like ultegra 11-32… do I need to change the derailleur?