# Shimano GRX shifter - Shimano SLX derailleur compatibility?



## regan40c (5 mo ago)

My checkpoint has a GRX shifter/der combo and I'm currently running a 11-42 11 speed cassette. I have a spare 11-50 11-speed cassette that I want to use, and I have a spare shimano SLX 12-speed derailleur. It's probably wishful thinking, but is there any chance my GRX shifter has the same cable pull ratio as my SLX 12-speed derailleur so that I can use them together with my 11-50 cassette?

I can install them and find out if they'll work, but it would be great if anyone knows so I don't waste my time doing that if they aren't going to work.
Thanks,


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## 6speed (Jun 18, 2021)

Alexdi at mtbr.com has a massive compatibility spreadsheet. It looks like they have different cable pull.


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## regan40c (5 mo ago)

6speed said:


> Alexdi at mtbr.com has a massive compatibility spreadsheet. It looks like they have different cable pull.


Wow, thanks for that link! Yes, it looks like they have a different pull ratio, bummer.


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## duriel (Oct 10, 2013)

Wolftooth makes a cable pull converter, I'm using one.


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## regan40c (5 mo ago)

duriel said:


> Wolftooth makes a cable pull converter, I'm using one.


Thanks for this. As best I can tell, my SLX 12 speed derailleur is 1.1 pull ratio and the GRX derailleur is 1.4.

The Tanpan info says is converts shimano 10 and 11 speed road to mtb... looking at that spreadsheet, the pull ratios seem to be all over the place. Do you know what the ratio of the pull converter is? I can't find that info online. Thx.


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## duriel (Oct 10, 2013)

All you need is the pull ratio for the shifter & RD, all the other info on other shifters isn't required. You need to know what shifter & RD you got, and that's it.


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## regan40c (5 mo ago)

duriel said:


> All you need is the pull ratio for the shifter & RD, all the other info on other shifters isn't required. You need to know what shifter & RD you got, and that's it.


I believe the SLX 12 speed derailleur is 1.1 ratio, but I can't seem to find the GRX shifter ratio.

I gave up on the pull converter idea and ordered a garbaruk derailleur cage, it replaces the stock cage and allows the derailleur to go up to a 50t cassette. I'll report back after I give it a try.









Rear Derailleur Cage for Shimano GRX 11-speed


IMPORTANT: The cage is to be used in 1x setup only with the rear derailleur(s) mentioned in Specification




www.garbaruk.com


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## regan40c (5 mo ago)

I got the garbaruk stuff installed last night, got out for a quick spin around the block and it all seems to work well (so far). While I was ordering the der cage I decided to order a new 11-50 cassette from garbaruk also, I couldn't remember how many miles I had on the old 11-50 chinese cassette and decided not to risk it. The garbaruk piece is quite beautiful (and light). It was 1/4 lb lighter than the SLX 11-42 cassette I replaced.


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