I agree, your setup is about 19-90mgearinches if im calculating it correctly. I have a Topstone w the GRX 800 and a wolflink on a double. 46/28 up front w a 11-46 cassette and I have 17-115 gearinches.

@@GasmanA nice! I think I would need you gearing if I was doing bike packing

36-52 is a common MTB setup

@@GasmanA is such low gearing necessary, or would you just end up spinning out even on a loaded setup, or perhaps too slow and lose balance, or even just too slow at 3km/h and might as well just walk? I wonder what is a practical low gear ratio

36t x11t on the other side = spin out

Seems like you could stick something, like a rolled up rag or a small cardboard box, between the cage and the derailleur to hold it open. Then, you'd have both hands free.

There you go. A block of appropriate size would work just fine 👍

Did you need to add a goat link to make it work without the SGS cage?

@@jamescourier1545 No, just a stock 812 directly on the derailleur hanger. It’s been working flawlessly for a couple of months. It’s way out of the officially announced gear range so nobody would even think of trying. I can’t paste the link here due to YT regulation, but there’s a video of someone trying out this setup.

But then you wouldn't have those big, sexy jockey wheels

That's interesting. Can you tell which Garbaruk cage is compatible with the RX derailleur?

That's a lot of range

@@thecleaner81 I looked our order up, it was RD cage for Shimano GRX 11s, though I can't tell a difference by the websites pictures from the (general) Shimano 11s, or if the Di2 versions (GRX Di2 &, XT/XTR Di2) are differently shaped. Note; Manufacturer's website says 1x only - never mind, don't be afraid to try and check with your chainline. 2nd note: we tried at first with the standard GRX pulley wheels, but in the largest (and the smallest?, can't remember) cog the - unfortunately very nice but no bargain - oversized pulley wheels by Garbaruk were better, no chain rub at the cage.

Don't you have a lot of redundant/overlapping gears with a big cassette and 2x cranks?

@@peterscott4183 theoretical probably but out in the field, it doesn't matter and nobody cares. Once the chain line gets too diagonal and the drivetrain too noisy (chainrub on FD and cogs), you don't have to, but usually simply switch rings. With those wide range cassettes you then basically have two 1x setups where you optimize the chainline. Bottom line, we don't shift in an mathematical sequential order if gearing, but how it makes sense in the terrain. Width of range without converting to 1x12 on Shimano HG was the goal and we have it. Once it gets really steep, you're in the small ring and that's it. The bike originally was equipped with a 32T 1x chainring with let the kid always be the slowest esp. in combo with the small wheels whe upsized a year later when he grew. So much better now, he's confident, reasonably quick among the older/bigger riders and foremost happy riding.

I'm looking to buy this RD and do this mod, pairing with a 38 or 40T up front. Do you reckon it would be better to buy the 126 link chain then and cut it down instead of the 116?

Wow, that's a great combo!! Is the RD total capacity enough to use all gears?

All but small and small, but the chain alignment doesn't allow that really anyway. 46 front in 11T rear and 30 front in 51t rear works fine.

Got it! Thanks for the info!!

GTK! I'm planning to run an 11-speed 42-11 with 46-30 cranks, RX-600, and GRX-812. First I'll try it without this cage replacement, but I happen to have a spare M8000 off a cracked frame.

@@shreddagorge I've run 10-speed 11-42 with GRX FC-RX800-2 48-31 cranks with the GRX RD-RX400 RD (which has the SGS cage already) and claims "only" 36T max cog and 41T total capacity.

Can you use a 12 speed chain instead of the 2 links? I got a spare chain. Do i have to remove links on the 12 speed chain?

The clutch? I prefer to index without the clutch on to eliminate the variable of additional stiction

Ok,but for the enclosing angle the clutch has to be closed. But everbody has their own mechanical Style@@TheBikeSauce

What chainring combo were you using?

@@drucyphr it's grx 810 double chainring: 48-31

Did you use the exact same parts, RD and cage as shown in this video? Was also thinking about extending the range of my current 2-by GRX setup

@@MrSchoeppel same question. cheers

@@MrSchoeppel yep, XT M8000 SGS cage + GRX RD-812 derailleur + much longer chain + b-screw adjustments

Probably an stereo full suspension. An reaction has an relatively short chain. Btw if these parts wear out fast you can swap to cues 11 speed. It does require a derailleur and shifter swap for 2-3x more service life.

@@barneyklingenberg4078 That's exactly what my next upgrade is going to be. I've been watching videos on Cues and they seem perfect for ebikes. Those thicker teeth on the chainring will be very strong. 300% more life apparently. I really should have done it already when my Derailleur got sucked into the wheel lol, but at the time I didn't really have the money, so it's on my list.

Exactly what I'm trying to accomplish. RD-RX812 (with M8000 cage mod) with an 11-42 M7000 cassette and GRX 46-30T cranks. Can you elaborate on the "fairly well" aspect you experienced?

Have you make that with the rx810 last year?

I used an 812 derailleur because the parallelogram geometry is designed for larger cassettes, I did not try this mod with the 810. I say fairly well because it was quite fiddly to get the b-screw just right. It looks like the XT cassette has more heavily profiled teeth compared to the 11-34 road cassette and I think that contributes to some of the clunking on up shifts. I notice it in the stand, but not on the trail. Or maybe it’s just the bigger jumps between the cogs.

@@dgc-3554 I've been running a 2x 810 with an 11-40 rear using nothing but a Goatlink. TBH I probably didn't even need that but I don't like the idea of the B-screw falling out.

​@@dgc-3554so do you recommend ur set up?

I was running 46t w GRX812 for a long time. 40t up front was just barely not enough for me.

I am using 51t without any modifications.

Your GRX RX400 RD already has the SGS cage (at least mine does). You don't need to buy anything.

Did you try this? Want to try it too

@@lastfm4477would this work with a 2x10 GRX 600/400 to got to a 1x12?

Would love to know too!

I have been wondering this, if it would work. Would be nice to see someone test it out in their cave of bad ideas. 😄

@@positiivi_temeI’ve see several people on Reddit saying it worked. The 11-40 is in my wishlist (I’m currently rocking the standard GRX812 2x 46-30 setup, with the 11-34 cassette)

It worked for me, I have the GRX 812 RD with 46/30 front and 11-40 rear. Going to try the same thing with the GRX 400 soon

​@MeowHikes did you modify the cage of the 812? Or stock

it depends if the outer cage is riveted to the clutch axle or bolted to the axle. If bolted, have fun

Do you use a Wolftooth or something to fit the 11-40? I have a GRX RD-RX810 in the back which (according to Shimano) should shift to max 34T in the rear. An 11-40 with a 46-30 in the front would be real nice for the steeper climbs around here.

No, no Wolftooth bit, b-limit adjustment sufficed. I learned this from Russ’s interview with Grant Peterson. He said Shimano is very conservative with such things.

Yes, he can benefit with longer chain. I'm also in the same setup. Not into 1x as it seems more limiting and I have 11-40 with only unwinding the B-scew.

Yea, this chain was stock length off the GRX 2x (11-32, 31/48) I think. An extra link would probably do it. New chain is already on the way.

I am also in the 2x camp. Tried and 11-42 cassete with the GRX810 (with direct mount goat) and it kind of worked, but shifting was not so nice. I didn't have a 40 cassete to try out ... currently running an 11-36 with 32/48 out front. Think is, I also do a bit of road riding on the bike, and the small cogs get used, on the larger cassettes, the 11 to 13 cog gap is very noticeable. I found out that the SUNRACE 11-36 cassete still has 11-12-13 on the smallest cogs, which is perfect for stretches of road, and then it gets bigger for offroad :)

Just throwing in my experience: running a 11-40 in the rear w/ a GRX815 Di2 derailleur, mounted to a 10-speed goatlink. Front is 46-30 AbsoluteBlack oval chainrings. Everything works great and I've got good range. My fitness is the determining factor before gearing in most instances.

Frisbee singles definitely have the tard look while sacrificing range🤷

Shimano and SRAM cassettes all have the same spacing (unlike Campagnolo). You can mix-match Shimano & SRAM.

@@lastfm4477 I know that Shimano and SRAM cassettes have the same spacings but according to Shimano a 1x GRX rear derailleur only works with an 11-40 or 11-42 cassette. I found out that it doesn't work well with an 11-32 cassette that I prefer to use in the very flat terrain I find in the area where I live. With the Garbaruk cage there isn't a problem, it shifts like a dream and I actually think Shimano should have made the derailleur like this.

Yea I’ve still got to get a proper chain at the proper length. I’ll do an update video soon

@@TheBikeSauce The best I could do with getting the parts is March :D that Outer plate seems to be out of stock everywhere. Anyways, thanks for the response.

​@@TheBikeSauce was there any planned update on this? No worries if not. I'm sure you have a lot going on.

anyways, this works like butter. Forget the 12speed derailleur. Now I'm 11/51 in the back with a 36t chainring loving life

The latest grx 822 rd can already handle 10-50t cassette. It’s just the brifters are pricey..

I am running a 11-40 cassette using a goatlink 10. Works fine for almost 2 years now.

@@markobolt9030 regardless of speed, do you think 40t cassette is optimal for 2x, what's left is but size the right chainring upfront, be it 46/30 or 42/26 or whatever is required and within the derailleur capacity?

The rx400 is already a long cage. But you could mount a rx812 instead of rx400. Its the same cable pull ratio. Rx400 is only a downbranded rx800 derailleur

Haha if you want smooth and quiet, 2x is always the answer. Chain angle on any 1x will introduce noise

Haven't tried with an 810 but rx will get to 46 on a 2x.

Hi! I've done this mod 2-3 months ago, while upgrading form 2x9 Sora that was as stock preset on my bike. I've done around 800km, had one bigger crash (bended hanger) and everything works perfect. I'm on 40 chain ring (Grx 800 with InPeak power meter) and Shimano 11-51 Deore 5100 cassette. I bought 138 link chain and shortened it to proper length. There's no strange sounds on hard gears (11T). On 51 ring there's little bit of cracking due to big chain crossing from front to back, but it's not much bigger than on my 1x12 Enduro bike, so for me it was perfect deal. If you'd like to have 1x system with good climbing potential - go for it! 😊

No need to swap the 822 cage. It can already handle large cassettes

I mean the rx822 is the STI cable pull ratio M8100 GS or SGS.

Yea ppl keep pointing it out. It’s what I had on hand. An old sram chain. I’ll update with a new 11 speed shimano chain at the right length.

Yea the long cage just barely takes app all the slack in this 11-51t. I'm nearly certain the SG cage wouldn't work here

@@TheBikeSauce that's not my understanding of how it works. The long cage is for taking up the slack in double setups, it has no impact max sprocket size in 1x applications. That's why Shimano lists them both as having 46 tooth max low sprocket for 1x. I could be wrong though!

I looked it up. 39 on the GS and 47 on the SGS. RD-M8000

@@drucyphr That's "Total capacity" you're referencing, which factors in multiple chainrings. The value in question is "low sprocket max" which is the same for the SGS and GS

@@MrJonas2255 The job of the long cage is to take up the slack between the "longest" and "shortest" lengths the chain has to be. ie: for a 1x setup the difference between the 11 and the 51t sprocket, and for 2x setups the difference between big/big and small/small. The required total capacity for this setup (11-51t) is 40. So, just outside the range of the GS. If you had the chain length perfect, maybe it would work, but you'd have almost no chain tension in the 11t (when railing down descents) and you'll beat the crap out of your chainstays. Likewise in the climbing gear drivetrain efficiency may suck with that much tension being put on the chain from the rear cage at such an extreme angle. You are however correct in your understanding that the pulley cage doesn't effect theoretical maximum sprocket size.

M5100 650g

Shimano MTB and road/gravel rear derailleurs have different pull ratios from 10 speed and up.

A GRX cassette and a MTB cassette is the same. Wouldn't that meen same pull ratio?@@neilgoth1974

Will update soon. I’ve got a properly sized shimano chain on there now and it’s better. But of noise, but not much more than any of my other 1x mtb setups. Able to backpedal really fast with no indication of dropping the chain.

@@TheBikeSauce That sounds promising. I'll let you know how the Di2 experiment goes.

That will allow for a bigger cassette, but will not extend the total capacity of the derailleur.

Yeah, usually replacing the cage is to increase the total capacity of a 1x rd for use with a 2x setup.

The main difference I see with the GRX 12 der is the upper pulley offset, which matches the 12sp Mtb der offset - SGS. The GS cages has about 10mm less offset, which I believe helps track consistently against the cassette - pulley to cog gap. GS is meant for 10-47, while SGS is for 10-51. The GRX cage swap in this case is dropping that offset lower than either of these, which I think will translate to the upper pulley having to track too far from the cogs as you move across the range. That’s what the b-tension adjustment is doing, as per comment above. I purchase a GRX 12 der to upgrade my 11sp setup, and have noted the cage is identical in configuration to the MTB ones. Meaning, you could run an XTR cage in the GRX 12 if you wanted to jazz it up, or a Kogel Kolossos if you want to go bling mode.

Spot on, but we needed the long cage to take up slack for the 11-51 range

@@TheBikeSauce I just tried the RD-5100 cage and it bolts on nicely and looks like it should work, but the way Shimano has shaped the back plate fouls on the A-knuckle as it spins. An aftermarket replacement that has a flat plate would probably work so I'll keep looking. Shimano might make a flat plate version too.