Cal398

I'd like to change my bike over from Rival 1 to GRX 1x (I prefer shimano braking and shifting), but I'm concerned that the shifting on the 9-46 cassette will be really rough.

I've read many reports online that it will shift into the biggest cog, but conflicting as to how smooth. Anyone here who uses this combination of GRX + 46t max cassette that can comment on the smoothness of the shifting? Is there any significant stuttering, mis-shifting, slipping off the cassette, etc.?

I'm honestly impressed with the Rival RD's ability to shift through this whole e13 cassette, but really can't get on board with the brakes, doubletap, and aesthetics. Just checking-in that I'm not making a huge mistake before dumping a bunch of cash on a new grx group.

Thanks all!

TooLegit

I'm using an 11-46 with a GRX812. It shifts perfectly smooth up and down all the way to the 46t. The caveat is that I have to use it with the clutch off. I get horrible shifting with the clutch on to any gear. I haven't noticed any excessive chain slap with the clutch off.

sdimattia

bikepacking.com tested the limits of the GRX derailleur at some point
I'm running GRX812 on a 11-42t cassette and a 46-30t in the front. I switched out the stock rear derailleur cage for an M8000 long cage and I have full use of the whole range with the clutch on or off. If I wanted to switch to a 1x, I could probably fit up to a 50t cassette with the longer cage.

bamboobike4

pic? Very interested, building my first gravel….

bamboobike4

I’m building my first gravel bike and would be interested in your Rival takeoff. I have some SRAM spare parts.

I have 1x11 Force AXS on a road bike (10-42 rear, with rings 44, 48, and 50 rings I can interchange up front.)

sdimattia

GRX812 with a M8000 cage. 11-42t cassette, 46/30t in the front. The longer cage goes up to 46t with a 1x though you probably get a 50t to work.

Stock cage (right) compared to the longer cage (attached to derailleur). Was an $18 fix and provided 10 minutes of fun tinkering.

base2 

I always thought that in mountain 11 speed, Shimano & SRAM were close enough that either companies derailleur could be used with either companies shifter.

The problem then would be to convert the GRX road 11 pull to mountain pull in order to utilize the (as designed) more capable mountain derailleur. That can easily be done with great success using a Jtek Shiftmate 8 or a Wolf Tooth TanPan.

Anyone is welcome to tell me I'm wrong as I have never actually tried cross mixing Shimano & SRAM mountain derailleurs, just in brand road/mountain via the pull ratio converter.

I've seen my fair share of derailleurs run out of spec. The linkage pivots tend to wear early & get sloppy in a short handful of seasons. The jockey wheels similarly wear early. Just because you can doesn't necessarily mean you should.

As to the video above: Nothing new here. Been doing that since GRX came out. What he forgot is to intentionally size the chain small/small for proper chain tension & to program the Di2 to disallow big/big to prevent unnecessary stress on the derailleur linkage. <sigh>

sdimattia

Sram, Shimano, and Campy all use different pull ratios so no, you cannot mix shifters and rear derailleurs between brands. I believe you can get away mixing some front derailleurs and shifters.

You can however, as you said, find workarounds within each brand to make their mountain and road parts work together.

base2 

That's what I thought too for the longest time. But, then I read this: Shiftmate Compatibility Charts and Choices - Jtek Engineering & at the very bottom is the Shiftmate Y. Considering it is these guys business to know these things, I accept that they may know a thing or two that I might not. So I changed what I thought to match their (to me, unsubstantiated) assertion.

Now I am curious enough & have resources enough to try. It sure would be cool. I'll be at my workshop for the remainder of the day. I'll post back with my findings.

sdimattia

Then let me amend my previous statement . . . Historically, it was not possible to mix components between brands. But now, technology allows us to do many things that weren't previously possible to do

There's already a variety of options to choose from when it comes to making road and mtb parts compatible. As you've pointed out, companies are now starting to offer options to mix brands as well. Personally, I've always used Shimano components since I started out with Shimano and am most familiar with their line. I've not heard of Jtek before but their stuff seems pretty cool. If there are in-line converters for mtb/road, why not make one to switch between brands?

base2 

That's what I intend to find out. Shimano road 11 (Ultegra, GRX, it's all the same) shift pull to mountain shift pull, to other brand (SRAM) even more capable derailleur that is supposedly close enough to not matter in practice.

We'll see. If it works it'll be a stroke of genius. Else, we'll know it was misguided.

bamboobike4

JTek does allow shifting between brands, but the mix (pre-11 sp) had to be at the RD/Cassette joint. I've used 10-sp Shimano wheels with 10-sp Campagnolo drivetrains, and a J-Tek, just fine. The opposite can be done, on 10-speed, by re-configuring the JTek. I finally decided just to use what the mfg's intended, not because of any loyalty, but because I make enough mistakes without tempting fate and Murphy.

base2 

So, I was mistaken. The Shimano offerings in 11 speed seem to be moreorless equal to SRAMs. Like a big dummy, I was mixing up SRAMs 11 & 12 speed groups. I was under the impression SRAM groups went to 50 teeth big cogs period. How SRAM names their groups is still something of a mystery to me. How is it that some GX 11 speed & some GX is 12 speed? This is genuinely confusing.

However it shakes out, in the above video you will see a Shimano 11 speed road shifter operating a SRAM 11 speed mountain derailleur. I don't know quite how I got on the "has to be SRAM" track but it works. 11 speed mountain is 11 speed mountain is 11 speed mountain, apparently.

Fentuz

is this a KMC chain? it seems to have the kmc X Bridge feature. It so, try a "cheap" Sram PC1110. I had a KMC chain that was super noisy with both SRAM 10-42 and 11-42. When I swap the 11-42 for SLX 11-46, it was noisier and annoying so I put a pc1110 and the noise went, shifting was superb thanks to hyperglide...
When I swap the 11-42 to 9-46, I found that the e13 shifted like a sram but it is not as good a SLX (Shimano is way smoother).

so SLX + GRX should work nicely if setup properly but if the chain is a little wide (due to the x bridge) it will be interfering with the cassette and be noisier. With the clutch the cage should create greater tension on the chain and therefore pull in the chain on the cog teeth for maximum seating. If the chain is too wide, the added tension may cause more interference leading to noise/poorer shifting.
Worth spending £10-15 ($15-20) of a SRAM PC1110 chain and give it a go

TooLegit

Thanks for the tip! Yeah, it's the KMC X11. I got it because it was the only thing I could find in stock at the time. I don't notice the noise too much. Maybe because I don't have anything to reference to. The shifting is fine but its unfortunate I can't use the clutch. I will definitely give the SRAM chain a go. I would love to use the clutch if I can.
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