The best mechanical 1x gravel derailleur for Shimano...is LTwoo!

[jonathanf2]

I've been tinkering around with my 11 speed mechanical gravel bike and picked up an LTwoo GR9 (with stabilizer) rear derailleur. Make note there are 2 versions of LTwoo's GR9/GRT rear derailleurs. One with stabilizer and one without. Anyways, I paired it up with Shimano 11 speed Ultegra shifters, Pass Quest 34t chainring, SRAM 12 speed GX chain and ZTTO 9-46t 11 speed XD cassette.

This setup was tailored to tackle the steep mountain trails in my area. Surprisingly it shifts great! LTwoo uses the Shimano 10/11/12 speed road/gravel pull ratio, so everything works perfectly. In fact I would probably opt for this rear derailleur over the 1x GRX 812/822 RD (even if running 12 speed). I prefer Shimano shifters over LTwoo shifters and this Shimano shifter/LTwoo RD combination works much better together in my opinion. 

[hsaus]

Opposites day!

I run LTwoo R9 shifters (2x) with Shimano derailleurs (R7000 front, RX810 back), and it also works great. Love the thumb shifter with multiple upshifts in one stroke (which LTwoo unfortunately moved away from in later iterations).

Ultimately though, I enjoy being able to mix and match groupset components, so we can all get exactly the setup we want. Or sustain our constant desire to tinker

[jonathanf2]

Opposites day!

I run LTwoo R9 shifters (2x) with Shimano derailleurs (R7000 front, RX810 back), and it also works great. Love the thumb shifter with multiple upshifts in one stroke (which LTwoo unfortunately moved away from in later iterations).

Ultimately though, I enjoy being able to mix and match groupset components, so we can all get exactly the setup we want. Or sustain our constant desire to tinker

It is fun mixing and matching groupset components! One thing I do find easier with Shimano mechanical shifters is routing shift cables and accessing the clamp screw. For 2x, I prefer Shimano front/rear derailleurs. It just seems with gravel 1x, Shimano has been a bit lazy. I tried running the GRX 822 RD and it's not really compatible with 11 speed, contrary to some reports. I even have the GRX 812 RD with Garbaruk cage, and I think the LTwoo GR9 works better!

I'm also running LTwoo ER9 on both my road bikes and I found it best using Shimano 2x chainrings and even swapping out the stock pulley wheels to Ultegra to get the best performance. 

[Pedaldancer]

Thanks for that knowledge sharing!

At least that means once Shimano 11sp mechanic spare parts are not available any more there's no pain.. just take the ltwoo.
And in the mechanic derailleur no electronics can die 

[00Garza]

I'm running Ltwoo GR9 shifters with GRX812 rear mech which shifts perfectly on my 11-46 sunrace cassette.
I like the ease of wheel changes with the on/off clutch. Indexing seems to stay in place better with the GRX mech.

[jonathanf2]

I'm running Ltwoo GR9 shifters with GRX812 rear mech which shifts perfectly on my 11-46 sunrace cassette.
I like the ease of wheel changes with the on/off clutch. Indexing seems to stay in place better with the GRX mech.

For some reason I wasn't getting great shifting with my GRX 812 RD especially with this older frame that has the top side (as opposed to rear) chain stay cable exit. Also from working with my other eGR gravel frame with similar chain tensioner, I found doing wheel changes in the 3-4 smallest cog makes it easier for wheel removal. I also prefer not having to deal with the GRX clutch, it's either too loose when OFF or too tight when ON (even with tool adjustment).

I recently did my buddy's gravel setup using a SRAM Rival 1x RD with knock-off Garbaruk cage. That RD setup shifts great, I'd probably go with the SRAM RD paired to a set of Sensah SRX HRD shifters (to use mineral oil brakes)! 

[gf]

On my gravel I run Ltwoo gr9 rear derailleur paired with Shimano grx 810 lever; but what do you mean when said gr9 has two version and one with stabilizer? A sort of friction as shimano rear derailleur?
Someone use gr9 rear derailleur with 50t cassette?
thanks

[jonathanf2]

On my gravel I run Ltwoo gr9 rear derailleur paired with Shimano grx 810 lever; but what do you mean when said gr9 has two version and one with stabilizer? A sort of friction as shimano rear derailleur?
Someone use gr9 rear derailleur with 50t cassette?
thanks

LTwoo makes a cheaper GR9 rear derailleur for cable disc brake and a more premium version for the hydraulic disc brake version.

[Changebiker]

In fact I would probably opt for this rear derailleur over the 1x GRX 812/822 RD (even if running 12 speed).

How comes - What's better?

[jonathanf2]

How comes - What's better?

If using 11 speed, works up to 50t if not bigger (GRX 812 RD at best can do 46t with no mods). Lots of B screw adjustment left even with a 50t cog. No need to decide if you need the medium (46t) or long cage derailleur (50t) if running 12 speed. I also prefer the clutch stabilizer on the GR9 since there's no on/off switch of the GRX RD. It's either too soft or too hard to shift (can adjust though). GR9/T shifts are crisp and spot on with Shimano shifters.

I actually give credit to LTwoo, their 1x RD is far better than their mechanical 2x road derailleurs (just stick with 105/Ultegra derailleurs). In fact the Shimano 12 speed 1x GRX RD ended up just using a similar design to the LTwoo GR9, omitting the shadow + design with additional hanger.

Included another shot.

[jonathanf2]

Oh yeah, I also feel the shift cable positioning is better suited for both rear exit and side exit chain stay cable holes. So if you have an older style frame (or steel/titanium/alloy frame design) that exits to the side chain stay, it should still shift fairly smooth. On the GRX RD is more optimized for rear cable exit holes. Also the GR9/T RD is cheaper than 11/12 speed GRX RD options.

Having used all of the above, even if I was building a premium mechanical 1x setup (gravel or road), I would still go for the LTwoo RD and a nice set of mechanical Shimano shifters (Ultegra/GRX even 105). I don't care so much for matching my components, as long as I get the best performance.

[Changebiker]

Thanks for the detailed input!

Just to add - the Shimano RD-RX820 for 1x12 should do up to 51 teeth and doesn't cost a fortune either.

[lavistaa]

Has anyone run a grt rd in 2x setup?   Id like to go to 40 in the rear and assume this can take the slack, but am not sure if there are other issues with using it with a 2x?

[jonathanf2]

Has anyone run a grt rd in 2x setup?   Id like to go to 40 in the rear and assume this can take the slack, but am not sure if there are other issues with using it with a 2x?

I tried seeing if it would work just using a 46-30t chainring and 10-42t cassette without the FD. The 30t chainring was able to properly secure the chain without any slack. With the right size chain I was still able to clear big/big and small/small without any compromises to shifting. Though I didn't try it out with an FD.

Also I did find issues using the LTwoo RD with Shimano shifters. Apparently Shimano shifters don't have enough force to properly shift from the big cog with the LTwoo GR9/T RD causing poor upshifting. Shimano shifters work best with the GRX and Ltwoo with the matching derailleurs.

Though I've since gone full electronic on all my bikes, so I haven't revisited this thread.