Camilo

Without getting into the minutia of the gearing I want on a build I'm thinking of (and thus avoiding the always helpful comments and advice that I really don't need such low gearing):

What wide range RD's are compatible with Shimano 10 speed road shifters? I'm not sure of the model of my 2X10 speed shifters, they're the early version with the external cabling (not under the bar tape). I've had them in the parts box for quite a while but they're relatively low usage and in perfect shape.

I know that 8 and 9 speed MTB RD's are compatible as I've built a couple of 10 speed road bikes with MTB RDs of the 8 and 9 speed type. That will work fine if I decide to go 2X (which is feasible since I have both right and left shifters!)

If I want to go 1X, I'd like to use a cassette that will take a 46t large sprocket. I see that there is a currently model Deore RD-M5120-SGS that looks like it will go to 46t on a 1X drivetrain, but as I currently understand it, the 10 speed MTB RDs are not compatible with 10 speed road shifters. FWIW I also have a set of Cane Creek brake levers that will pull the canti brakes on this build, so I have the left lever for this option as well.

I think the Microshift Advent wide range 9 and 10 speed RDs are apparently not compatible with anything but their own Advent MTB shifters? The XLE 10 speed long cage RDs say compatible with Shimano MTB shifters, so I assume this means they have the same compatibility as Shimano 10 speed MTB derailleurs - not compatible with road shifters.

I'd appreciate any corrections to my understanding, information and advice, thanks.