Is there a Shimano 9-spd compatible (to work with a 9-speed 105 STI shifter) rear derailer that can handle a 46t rear cog?

Thanks!

three words that will make you happy... search: Derailleur Hanger Extender.

search it, buy it, use it... i do.

very few, if any, 9sp. derailleurs will handle an 11-46 cassette without the extender.
Microshift Advent may be one of those, but they are not the best derailleurs, IME... there's a recent thread about those derailleurs, btw..

what derailleur is currently on the bike? it may be a short cage der, in which case you will need an MTB design derailleur that offers more "Wrap" to accommodate things.
what gearing is or will be used on the front? that figures into total Wrap too...

Shimano long cage mtb derailleur, i.e., Shimano rd-592

There is no Shimano compatible 9 speed rear derailleur that can handle a 46t cassette. You can make one reach with a hanger extender, but shifting into the smaller cogs will suffer.

Advent will do a 46t cassette, but it is only compatible with Advent shifters.

Shimano 9 speed MTB derailleurs will not work with anything larger than a 36t cassette.

... and a hanger extender....

max. low gear size of 36 or so..... with no hanger extender... and it has a max Wrap of 43.
Shimano MTB 2011 Deore RD-M592 SGS 36 32 18 43

from this wonderful spreadsheet...
https://docs.google.com/spreadsheets...#gid=847158527

https://sunrace.com/product/rdm900-md/

You mean RD-M592. That one has a 45T total capacity, but the max cog size is 36T:
https://si.shimano.com/en/pdfs/si/5W...0B-001-ENG.pdf

Ha, yes, I started that other thread as well. Same bike. I had been thinking of changing the Advent out for a Shimano derailer and swapping out the shifter with a 9-speed 105 one that I have in the parts bin. The gearing is 1x9, 42 on the front and 11-46 on the rear.

This is the only thing I am aware of that technically should be able to do it with a 9-speed Shimano lever. Having used one with a 11-42 in the past, I can say that at least with a 42t, it does not index well enough to be used with indexed shifting, maybe it could work with a 11-50, and I wouldn't expect great results with 11-46. The clutch is rather pathetic, and I have seen a video of someone trying to use one with the 50t it was designed for, and it was necessary for them to snip the end off of the lever for the clutch, as it would otherwise grind against the 50t cog. I was really excited to hear that this derailleur exists, but actually using it was quite a disappointment.

I have gotten a 9-speed XTR M952 with a hanger extender to work fine with 11-42, but it doesn't look like it would be happy trying to clear a 46t cog.


If you already have Advent, I would expect it to work better than any attempt at getting a 9-speed 105 shifter to shift a 11-46 cassette.

You can run a Shimano 10 or 11, or a SRAM 11-speed MTB RD with a 1:1 SRAM 9-speed shifter

Lots of people have made that comment about the higher gears suffering but after about 10 years of using one, I’ve not noticed any problems.