Tuesday, April 23, 2024

GRX 822RD on 11 Speed bike

Having a 1x mountain bike, I always considered a one-by for the gravel bike as well, but the range on available systems was somehow limited, as I use the bike also for some road riding, so the 11-42 range available on the GRX 11 speed was a no-go. (New post coming up with the "science" of 1x).


With the launch of GRX 12 speed, the rear-derailleur was "updated" (basically it's a M8100 mountain bike derailleur with a tweak on cable pull), which means a 10-51 cassette was possible.


Upgrading to GRX 12 speed would however be... expensive, as it would be necessary to replace shifters (super expensive), wheel hub to microspline, basically with the exception of the chainset, everything.

With the launch of the Deore 11-51 11 speed cassette, this made things very tempting.


Basically all information out there is that using the 12spd rear derraileur on a 11 system would NOT WORK.

However, I saw a youtube video of a guy claiming it DOES work.

Looking at the comments, most of the people that tried it mention it does not work, however I had to try.

Got a 50% deal on the RD, the cassette can always be used for the mountain bike, so let's go.
Installation was simple enough, but ... spend some time trying to get the thing to work, to the point it "almost" works, but not.
I can get about 9 of the 11 speeds to work correctly, but it misaligns with each click of the lever, so ... basically a different pull-ratio. Close, but no cigar.

After some time tweaking it, it looked good on the stand.

Took it out for a ride and... nah.
The 13t cog clicks and jumps, and the 51 and 45 "tick" and I had to constantly hold the lever on a steep ramp so it would not jump out of the '51.
After a bit more investigation, I was about to give up.
Found another video, and the concerns are true, it does NOT WORK.

However, the guy on this video (thank you thank you thank you) mentions that moving the cable pinch bolt, seemed to help, but there is a "knob" on the way...

  


basically this protrusion

Removing that, one can pinch the cable BELOW the bolt, so it gives it like a 5mm longer lever of action for the same cable pulled. This should be enough to move the derailleur the extra bit it needs to shift an 11 speed cassette. ( The spacing of cogs on 11 speed is slightly larger than 12 speeds, so it all makes sense).

I grabbed the dremmel, and cut it off, grinded it to make it smooth so the cable does not fray, and gave it a try.

There it is. Not the best of jobs, but smooth enough :)

Cable now clamps below the bolt. (Yes, it is too short, but I didn't want to get a new cable in just for the experiment. I'll just superglue the end so it does not fray and run it till it breaks.)

Testing it and ....

IT WORKS !!!! Much better and easier to index, limit bolts could be set as normal. Everything like it was "meant" to be.
Testing it, I was afraid that coming down from the 51 was a tad slow ... maybe it was just from the video with the guy that did not cut the tab, or just my impression, but it was a concern.

I took the bike out for a "proper" gravel ride and it is AMAZING !!! All the gears work, no clicking, no noise, no need to hold the lever for 51, it was brilliant !!! 
Riding 1x on gravel is how it should. I had no issues with the difference between gears, but not needing to change at the front and be concerned in what gear I was at the back, was I crosschaining, etc etc 

It is just nicer to just click + or - and done.

This is kind of a "destructive" mod, but I highly recommend it. Going 1x on gravel is worth it, but without at least an 11-51 your range will be lacking.

The only "proper" alternative I see to this, would be the GRX812 + M8000 cages, but the GRX822 RD looks badass !
(Or running the new 12 speed groupset all together, but I mean, alternative to people who already have an 11 speed GRX and up to mullet it up).

Now I'll just put some nail polish, or touch up paint or whatever there and here we go !
Maybe when it's time to replace the cable I'll scratch a groove there ... 
But it seems to be working fine now, I don't want to jinx it.

If you try it, let me know how it went !