Author Topic: LTWOO ER9 & ERX - Electronic groepsets  (Read 1450646 times)

lavistaa

Re: LTWOO ER9 & ERX - Electronic groepsets
« Reply #1515 on: June 09, 2025, 03:12:07 PM »
What size chainrings are you running with the 11-36t? I tend to like my shifting to be crisp and tight, especially when I was first switching from my properly tuned mechanical Ultegra R8000 setup. I felt 50-34/11-34t was the max for keeping decent performance. 50-34t or 52-36t with an 11-32t is would be optimal.


I originally used a 46/30 but am now using a 50/34.   It’s as good as a mechanical ultegra rx running an 11-40 with a 46/30 (9I run a brand a test all the odd stuff we can find; ultegra rx, xt (11 speed) di2 on my other bikes.

1jzsupra

Re: LTWOO ER9 & ERX - Electronic groepsets
« Reply #1516 on: June 09, 2025, 10:39:00 PM »
New to the forum.  I have a 1st gen LTWOO eRX on an ELVES frame that I built up.  It's been FLAWLESS for about 1000 miles at this point to include a 90-mile ride and a 105-mile ride.  I went to wash it and avoided water on the derailleur....   DEAD.  It flashes red lights when you attempt to operate the shifter and does not do anything.

The good:
1.  I got it from LTWOO's official account on Aliexpress and they are pretty good at helping.  They did ask for a video to confirm and sent it to a tech.  By the next day, they had already agreed to send me a new unit.
2.  Based on the photo they sent me, it looks like they are sending the most up-to-date rear derailleur.  Hopefully, there isn't any issues with compatibility. 

The inconvenient:
1.  I had to pay for shipping, which I was prepared to do.... But I wasn't expecting it to be $65.  I was thinking around $20.
2.  Time difference is a factor in how long the process takes.  Obviously, they are in a different time zone, so it took about 5 days of talking to get it all sorted.


elmtree

Re: LTWOO ER9 & ERX - Electronic groepsets
« Reply #1517 on: June 09, 2025, 10:57:14 PM »

The good:
1.  I got it from LTWOO's official account on Aliexpress and they are pretty good at helping.  They did ask for a video to confirm and sent it to a tech.  By the next day, they had already agreed to send me a new unit.
2.  Based on the photo they sent me, it looks like they are sending the most up-to-date rear derailleur.  Hopefully, there isn't any issues with compatibility. 

The inconvenient:
1.  I had to pay for shipping, which I was prepared to do.... But I wasn't expecting it to be $65.  I was thinking around $20.
2.  Time difference is a factor in how long the process takes.  Obviously, they are in a different time zone, so it took about 5 days of talking to get it all sorted.

The new one doesn't have a charging port at the rd. They moved it to the fd. Seems like you'll be unable to charge?

Lotnik

Re: LTWOO ER9 & ERX - Electronic groepsets
« Reply #1518 on: June 10, 2025, 02:21:52 AM »
The good:
1.  I got it from LTWOO's official account on Aliexpress and they are pretty good at helping.  They did ask for a video to confirm and sent it to a tech.  By the next day, they had already agreed to send me a new unit.
Just a hint. LTWOO doesn't have official account on Aliexpress. LTwoo official store it's only a name of the reseller store ;)

1jzsupra

Re: LTWOO ER9 & ERX - Electronic groepsets
« Reply #1519 on: June 10, 2025, 06:53:47 AM »
The new one doesn't have a charging port at the rd. They moved it to the fd. Seems like you'll be unable to charge?

After looking into it further. It is NOT v3, its a V2 "blue" edition. 
« Last Edit: June 10, 2025, 10:48:33 AM by 1jzsupra »

1jzsupra

Re: LTWOO ER9 & ERX - Electronic groepsets
« Reply #1520 on: June 10, 2025, 06:54:22 AM »
Just a hint. LTWOO doesn't have official account on Aliexpress. LTwoo official store it's only a name of the reseller store ;)


Ohhhhhhhhhh lol.  Well. Either why they did pretty good.

Sgt.Hole

Re: LTWOO ER9 & ERX - Electronic groepsets
« Reply #1521 on: June 10, 2025, 03:25:06 PM »
My first gen erX worked also flawless about 2000km and two months.
But month ago it started draining batteries 2% in a hour while standing still

Pumpkin

Re: LTWOO ER9 & ERX - Electronic groepsets
« Reply #1522 on: June 22, 2025, 09:34:34 AM »
My first gen erX worked also flawless about 2000km and two months.
But month ago it started draining batteries 2% in a hour while standing still
Same thing happened to my ERX. Contact the seller, you will get a new RD. It takes a few weeks, but try it.

jonathanf2

Re: LTWOO ER9 & ERX - Electronic groepsets
« Reply #1523 on: June 22, 2025, 11:57:22 AM »
It's been over a year and both my ER9 groupsets are still running. I don't wash my bikes and I don't ride in the rain, both my ER9 RD battery ports are covered in both dielectric grease and sealed with rubber cement. I was tempted to buy the new V3, but no point upgrading if it ain't broke!  ;D

pavlo.k

Re: LTWOO ER9 & ERX - Electronic groepsets
« Reply #1524 on: June 22, 2025, 05:03:44 PM »
My ER9 rear derailleur seems to have very weak spring tension in the cage, which causes a lot of chain slap. I know it doesn’t have a clutch, but even compared to the Ultegra Di2—which is already not great at maintaining chain tension—the ER9 is noticeably worse. I only use it on the road, so there’s nothing out of the ordinary: just the occasional crack, pothole, or speed bump.

I’ve applied thick PPF tape over the chainstay, but it hasn’t helped much. The tape is already torn in several places, and the paint on the frame has a couple of deep chips. I wanted to increase the cage tension by hooking the spring into a different hole on the cage, but to my surprise, the cage is riveted to the derailleur body rather than bolted—so there doesn’t seem to be an easy way to remove it. I also tried looping the spring one more time around, but that made it too tight.

Is there anything else I can try to fix the weak chain tension?

jonathanf2

Re: LTWOO ER9 & ERX - Electronic groepsets
« Reply #1525 on: June 23, 2025, 11:08:17 AM »
My ER9 rear derailleur seems to have very weak spring tension in the cage, which causes a lot of chain slap. I know it doesn’t have a clutch, but even compared to the Ultegra Di2—which is already not great at maintaining chain tension—the ER9 is noticeably worse. I only use it on the road, so there’s nothing out of the ordinary: just the occasional crack, pothole, or speed bump.

I’ve applied thick PPF tape over the chainstay, but it hasn’t helped much. The tape is already torn in several places, and the paint on the frame has a couple of deep chips. I wanted to increase the cage tension by hooking the spring into a different hole on the cage, but to my surprise, the cage is riveted to the derailleur body rather than bolted—so there doesn’t seem to be an easy way to remove it. I also tried looping the spring one more time around, but that made it too tight.

Is there anything else I can try to fix the weak chain tension?

First what chainring and cassette combination are you running? The ER9/X officially supports a "measly" 11-32t cassette max. I'm running both a 50-34t/11-34t and 52-36t/11-32t combo on both my bikes, but I found a few things to optimize performance. First make sure your chain is sized perfectly. Even an extra link can throw things off. Second swap out your pulley wheels to Ultegra/DA upper/lower 11t wheels. This will allow you to move the upper pulley wheel closer to the small cog. It will help in tighter shifting and will keep the chain better engaged. Also I'd turn on gear protection to avoid cross chaining.

The ER9/X definitely has weaker chain tension compared to a Shimano RD. I ride my bike ER9 bikes on really bad urban roads and light gravel. The steps above should help remedy your issue.

hsaus

Re: LTWOO ER9 & ERX - Electronic groepsets
« Reply #1526 on: June 23, 2025, 08:01:41 PM »
I'm slowly building up a new bike with L-Twoo eR9 v3, and right now I've set it up with 52/36T chainrings and a 11-34T 12-speed cassette. It seems to work just fine, though I've only shifted in the workstand so far. I also have plenty of B-screw threads to go.

Previously, when I tried the same 11-34T cassette with L-Twoo eR9 v1, I had to wind the B-screw almost all the way in to clear the largest cog.

Makes me wonder if there are some geometry differences between the v1 and v3 rear derailleur? Though I haven't spotted any so far. Or I made some other mistake when trying 11-34T on the v1.

The frames are not the same, but the chainstay length is only 5mm different (longer on the bike with v3).

Unknownftp

Re: LTWOO ER9 & ERX - Electronic groepsets
« Reply #1527 on: June 24, 2025, 02:14:12 AM »
My ER9 rear derailleur seems to have very weak spring tension in the cage, which causes a lot of chain slap. I know it doesn’t have a clutch, but even compared to the Ultegra Di2—which is already not great at maintaining chain tension—the ER9 is noticeably worse. I only use it on the road, so there’s nothing out of the ordinary: just the occasional crack, pothole, or speed bump


Did you try unscrewing the little Phillips on the derailleur body? I have 1st gen erx and I was able to take the cage out and give it more tension. Mine was slipping under tension even with properly sized cable. I have some photos of the disassembled derailleur.

jonathanf2

Re: LTWOO ER9 & ERX - Electronic groepsets
« Reply #1528 on: June 24, 2025, 11:32:39 AM »
My ER9 rear derailleur seems to have very weak spring tension in the cage, which causes a lot of chain slap. I know it doesn’t have a clutch, but even compared to the Ultegra Di2—which is already not great at maintaining chain tension—the ER9 is noticeably worse. I only use it on the road, so there’s nothing out of the ordinary: just the occasional crack, pothole, or speed bump


Did you try unscrewing the little Phillips on the derailleur body? I have 1st gen erx and I was able to take the cage out and give it more tension. Mine was slipping under tension even with properly sized cable. I have some photos of the disassembled derailleur.

Getting that upper pulley wheel as close to the small cog makes a huge difference. This is part of the reason I recommend switching to Ultegra 11t/11t pulley wheels. In fact my small chainring and small cog only have a 2-3mm gap from touching the rear RD assembly. This is why I also use gear protection to avoid the two smallest cogs when in the small chainring. I also don't need my big/big combo either.

Weak spring tension was one of the first things I noticed on the ER9. I was getting chain drops from fast downhill descents especially in the big/small combination. Since getting my ER9 RD dialed in, I can now ride confident I won't get chain drops or chain slap.

pavlo.k

Re: LTWOO ER9 & ERX - Electronic groepsets
« Reply #1529 on: June 24, 2025, 03:54:28 PM »
Did you try unscrewing the little Phillips on the derailleur body? I have 1st gen erx and I was able to take the cage out and give it more tension. Mine was slipping under tension even with properly sized cable. I have some photos of the disassembled derailleur.

I haven't seen any philips screws on the body. Only the rivet holding the outer cage plate but i don't think there's any way to remove it.

Getting that upper pulley wheel as close to the small cog makes a huge difference. This is part of the reason I recommend switching to Ultegra 11t/11t pulley wheels. In fact my small chainring and small cog only have a 2-3mm gap from touching the rear RD assembly. This is why I also use gear protection to avoid the two smallest cogs when in the small chainring. I also don't need my big/big combo either.

Weak spring tension was one of the first things I noticed on the ER9. I was getting chain drops from fast downhill descents especially in the big/small combination. Since getting my ER9 RD dialed in, I can now ride confident I won't get chain drops or chain slap.

 
I tried ultegra pulleys today and I don't think I understand how it would allow for a smaller b gap. I haven't  noticed a difference. Upper pulley on er9 is 11t as well whilst ultegra lower pulley is 1t smaller and its not narrow wide but I dont think it affects the b gap in any way

I will see if it improves the shifting though. What I noticed is that a shift accuracy depends on whether you upshift or downshift into a specific gear. For example if I shift into the 4th gear from a larger cog its ok but when I shift to the same gear from a smaller cog, the chain starts catching the next cog and makes noise. It kinda feels like a sloppy guide pully
« Last Edit: June 24, 2025, 04:01:40 PM by pavlo.k »