$25 BUDGET MULLET!! // Shimano GRX 812 + XT Cage 

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

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.

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?

@@ChilkoNZyes get the longest chain you can the cut whatever you don’t need.

I assumed I also can try use Cage RD Deore M5100 SGS

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 👍

just dab your screwdriver in some assembly grease and that fairly light screw will stick. or get the fancy magnetised one.

Helpful hints guys, much appreciated. I will try to mod my rd-rz812 this evening 😅

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

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

Would love to know too!

you tried?

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.

What length chain did yoh used? 116 or 118?

@@Nevseremos1 116, i think. Just a normal shimano hg chain. The chainstay on my bike is quite short (420mm), though.

That’s a solid idea. It could potentially increase the drivetrain capacity, but it wouldn’t help with the max cog spec.

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! 😊

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

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

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

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.

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?

​@@jkzv1you should technically be able to use a 12 spd chain although I wouldn't recommend it as the inner width does change

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?

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.

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

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🤷

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.

with this modification the grx 400 would work with a 1x 50t cog?

M5100 650g

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.

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

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?

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