LTWOO ER9 & ERX - Electronic groepsets

[aramus1979]

I checked it for you, mounted rear derailleur eGR front eR9 works together, gear change works RD reacts to the right brake lever FD reacts to the left brake lever so the sets can be swapped. A large beer is due

[jonathanf2]

for those interested - the eR9 brake levers work with the eGR rear derailleur and vice versa, the eR9 rear derailleur works with the eGR brake levers

Finally we have confirmation! I might just pick up an EGR RD and run one of my road bikes in 1x with wide range cassette!

[boxof13]

I checked it for you, mounted rear derailleur eGR front eR9 works together, gear change works RD reacts to the right brake lever FD reacts to the left brake lever so the sets can be swapped. A large beer is due

You're a hero! We owe you a huge can of beer, for sure. I might actually just get a set of eGR and set it 2x for a gravel frame that I just bought, since I have an extra FD lying around! I might even get away with just purchasing eGR RD and transfer one of my two eR9 to save a bit of cash.

[amacal1]

I checked it for you, mounted rear derailleur eGR front eR9 works together, gear change works RD reacts to the right brake lever FD reacts to the left brake lever so the sets can be swapped. A large beer is due

Incredible! You're now the hero of this forum. Seriously cool of you to drop this info!!!

Edit: On a more sobering note, surely you run out of derailleur takeup for a wide range cassette + 2x chainrings. But, even if you're somewhat limited on the number of gears or functional configurations of your setup, simply being able to mix/match parts to get a working groupset together is incredible value. I can't fathom why Ltwoo wouldn't advertise (or even mention) this fact?!

For me, personally: Right now I have an eGR. If I wanted to turn my 1x gravel bike into a road bike is swap my crank, swap my cassette, and clamp on a front derailleur. Boom. Now I've got a 2x road groupset. Hell, I think I can get 2x chainrings for my current crank, so really I just need to bolt on a new chain ring, clamp on a front derailleur, and swap my rear cassette and I've got an entirely new groupo.

[SillyMochi]

aramus personal hero!

Yeah er9+egr RD would be my favorite 2x12 gravel groupset as well. But why the hell is the single EGR RD so expensive? ~130 USD more than the er9?

[jonathanf2]

I didn't even think about 2x gravel! 

I have a 10-42t cassette and 46-30t chainring. That combo would give great high and low gear range. I could even try slapping on a 9-46t!

[jonathanf2]

Just to confirm though. The EGR battery pack only has 1 cable port. You'd need a 2 cable port battery pack. Also is there any confirmation that the EGR RD will talk to an ER9/X FD if hooked up together?

[Sebastian]

I didn't even think about 2x gravel! 

I have a 10-42t cassette and 46-30t chainring. That combo would give great high and low gear range. I could even try slapping on a 9-46t!

46/9 would be an absolutely gianormous gear. That’s the equivalent of a 56/11.  I’m running Ekar and with a 38t chainring and a 9t cog in the back I can comfortably pedal 55k/35mph on descents. More with a high cadence.

[aramus1979]

Just to confirm though. The EGR battery pack only has 1 cable port. You'd need a 2 cable port battery pack. Also is there any confirmation that the EGR RD will talk to an ER9/X FD if hooked up together?

this is how they work together

[SillyMochi]

Okay, so if you wanna go down that road (pun intended), the best way would be to order a ER9 group and a spare EGR RD and link them together.

And if the RD fails for whatever reason, you still have a spare ER9 RD to use until your EGR replacement arrives 

[jonathanf2]

this is how they work together

Oops didn't see your other post! If that's the case this is huge. Yeah you deserve a beer! 

Now makes me think I should consider 2x + EGR on my gravel bike. I'd be fine with 46-30t + 10-42t. That would cover most my local climbing terrain with ease. Though you'd need to have both ER9 gruppo + EGR RD.

New thoughts: I did try running my GRX 812 RD + Garbaruk cage with a 10-42t and 46-30t chainring. An issue I faced is that I still had to make additional clearance with the 42t cog with the B screw when using the small 30t chainring, affecting high gear/small cog shifting performance. There's a good chance running FD + EGR might not shift well.

[lavistaa]

deliberately avoiding cross chaining easily adds at least 4 teeth to any rear capacity. I am guessing a 42 or possibly 46 would shift with a 46/30.  A 50/34 could probably shift to 42.   The cage on the egr must be benefiting from narrow wide pulley wheels. I had a 1x derailleur cause chain suck in the smaller cogs so I’m glad to hear it shifts well- definitely getting an egr rear mech!

I set up DI two drive trains using this technique. A 44/28 and 11-46 with great shifting is cake. I just lock out the cross train gears maybe one or two down near the end.

I don’t see a lockout or synchronous shift option in the ltwoo app, but it would be readily implemented.   I’m guessing with the acquisition of rotor, they intend to continue to invest so I’m hoping for this sort of programmability.  Embracing the software side of this would give them a huge lift.

[Sebastian]

The eGR RD has a clutch, right? Wouldn’t the higher chain tension impact front shifting. Does it work reliably? I’d imagine it’s like with Sram’s mechanical 1x RDs. You can’t combine these with an FD AFAIK. Never tried it but I can’t imagine that it’d work with that amount of chain tension.

[Bigbobby1482]

The eGR RD has a clutch, right? Wouldn’t the higher chain tension impact front shifting. Does it work reliably? I’d imagine it’s like with Sram’s mechanical 1x RDs. You can’t combine these with an FD AFAIK. Never tried it but I can’t imagine that it’d work with that amount of chain tension.

It works fine. GRX 2x RD also has a clutch. Shimano also has MTB groupsets with clutch and they work fine

[SillyMochi]

The GRX 2x "only" has to work with an 11-34/36t cassette. I could still see issues with larger cogs say 42t or even 46t. Limiting 2-3 cogs on either extreme end as suggested by lavistaa could help with the issue and still allow for a huge capacity.
But we won't know for sure until someone tries it for real.

Someone! Try it! Now!