LTWOO ER9 & ERX - Electronic groepsets

[nick82]

Hello! I'm looking into buying a Ltwoo eRX v3, the newest model, but I'm planning to use it on 1x setup. Is it possible to just connect FD from time to time to charge batteries? Or the front deralliur has "brains" of the groupset inside?

im pretty sure you could but you would have to leave the cable accessable or fish it out of the frame, why not just buy eGR? its compatible with a larger cassette as well

https://www.ltwoo.com/en/seriesItem?typeId=82&series=EGR

[TheVimpi]

im pretty sure you could but you would have to leave the cable accessable or fish it out of the frame, why not just buy eGR? its compatible with a larger cassette as well

https://www.ltwoo.com/en/seriesItem?typeId=82&series=EGR

Well, I like new shifter design better, so I wanted to go with eRX

[mashiro2004]

Something strange happened to me today. While I was riding, the gear shifter suddenly died. I thought I'd try plugging it into a charger. Luckily, there was a house along the road with some guys who had power and a charger. Given the bad experience, I bought a mini power bank to leave in my underseat bag.



The only thing I can think of is that I hit a big pothole shortly beforehand. Did the gear shifter go into "protection mode"?

[kbernstein]

Something strange happened to me today. While I was riding, the gear shifter suddenly died. I thought I'd try plugging it into a charger. Luckily, there was a house along the road with some guys who had power and a charger. Given the bad experience, I bought a mini power bank to leave in my underseat bag.

You're in for a bad surprise when you realize the groupset won't charge using a USB c cable

[mashiro2004]

I already have several power banks (larger ones) and they all charge if I use the USB-A to USB-C cable, but with they don't charge if I use USB-C to USB-C. The power bank in the photo is USB-A to USB-C.

[pavlo.k]

Something strange happened to me today. While I was riding, the gear shifter suddenly died. I thought I'd try plugging it into a charger. Luckily, there was a house along the road with some guys who had power and a charger. 

The only thing I can think of is that I hit a big pothole shortly beforehand. Did the gear shifter go into "protection mode"?

That's exactly what happened to my v3 on a third ride and now I'm paranoid. Never had any issues with v1. Someone mentioned that if a battery charge is very low, it gets cut off to prevent full discharge and it could also be caused by a vibration from hitting a pothole if the holder loses contact with a battery. I don't remember hitting a potlohe though and it's the same battery I've used for over a year with no issues

[Rajmundx]

I also have the V3, and after riding about 350 km so far, I haven’t had any problems. I also charge the drive before every ride so there are no surprises. I hope everything will go smoothly ^^

The only issue so far is the loud operation of the rear brake, but that’s probably a matter of the disc. I bought an III Pro on AliExpress and it’s very noisy—as if metal is rubbing against metal rather than the pads against the disc.

[mashiro2004]

My battery was at 65%, the group is an ER7. I've been using it since September, and I've done over 2,000 km. After connecting and immediately disconnecting the charger I then drove the remaining 50 km to get home without any problems and without having to do anything else. For that matter, I think the protection went off. I remember the pothole perfectly, as my initial fear was that I'd punctured or damaged the rim. The impact was quite severe.

[mashiro2004]

I may have found a better solution. The problem with the switch is that it doesn't have the proprietary USB-C PD protocol, so it won't charge from USB-C to USB-C. So this morning I tried using a USB OTG adapter and then a USB-A to USB-C cable with my Samsung Galaxy S25. And bingo, it works.

[mashiro2004]

I can use same trick with usb-c powerbank and otg adapter

[pavlo.k]

I have this cyclami light that is also a powerbank. It has thunderbolt<->usb-c cable that also serves as a strap. When i connect thunderbolt side in the light and usb c into the fd it does charge it so I hope it will wake it up if dies again.


https://a.aliexpress.com/_EHiGuR8

[mashiro2004]

I have this cyclami light that is also a powerbank. It has thunderbolt<->usb-c cable that also serves as a strap. When i connect thunderbolt side in the light and usb c into the fd it does charge it so I hope it will wake it up if dies again.


https://a.aliexpress.com/_EHiGuR8

if you plug it in do you see the battery charging?
If it charges it means that your power bank charger is not USB-C PD, if it doesn't charge it, you can try as I did by putting a USB OTG cable and a USB-A to USB-C cable.

[nick82]

i have noticed there is quite a lot of play in the fd when its on the lower chainring, is anyone elses like that? on the outer the cage is solid but on the inner position you can wiggle it around and worse even at its most inner position there is a tiny bit of chain rub on the 2 largest sprockets but you can manually move the cage in by pressing it enough to remove any rub

[jonathanf2]

i have noticed there is quite a lot of play in the fd when its on the lower chainring, is anyone elses like that? on the outer the cage is solid but on the inner position you can wiggle it around and worse even at its most inner position there is a tiny bit of chain rub on the 2 largest sprockets but you can manually move the cage in by pressing it enough to remove any rub

I always adjust for the biggest and smallest chainring using the app. Also make sure the FD is firmly screwed in. Just don't over tighten, you might strip the FD screw thread. Also don't forget there's also the trim which should help a bit at the low and high gear settings.

[mashiro2004]

Since I like to "understand" things, I tried to ask LTWOO support for an explanation of the behavior.
My Question:
I have a Ltwoo ER7 derailleur with which I've ridden over 3,000 km. Something strange happened today. While I was riding, the derailleur died, showing no signs of life, everything was off, even when I pressed the rear derailleur buttons...
I thought about trying to connect it to a charger. After plugging it in and out (without doing anything else), the derailleur came back on and everything restarted perfectly.
The only thing that happened shortly before was that I hit a big pothole. Could the derailleur have gone into "protection mode" and by plugging in the power cable I "reset" it?
Now everything is working fine, I just wanted to understand what could have happened.


Their response was as follows:

1. Based on your text description, we cannot determine the cause of the malfunction. Please provide a video demonstrating the problem.

2. Please provide proof of purchase, a screenshot of your buyer information from the shopping platform, and your shipping address.

3. Please follow the steps outlined in to troubleshoot the problem and record a video of the process to help us analyze the cause.

My reply:

Hi,

1) I can't make a video now because now work correctly.

2)  i attach image of aliexpress order

3) None of the scenarios in the video happened.
The rear derailleur didn't give off any lights. Not even when I pressed the button for 30 seconds.
The front derailleur didn't respond to the left shift command.
The groupset wasn't reachable from the app.
I connected the USB-C charger to the front derailleur for 10 seconds and then disconnected the charger. As soon as I disconnected the charger, everything started working again, and I rode another 50km home. The battery was still at 65%. I didn't touch anything else, and everything worked fine again.
That evening at home, I recharged the battery, and it charged correctly to 100%.

My intention is to understand what really happened, why, and whether it could happen again, and under what circumstances.
Notwithstanding the fact that I now always have both reverse charging cables from my smartphone and a mini power bank with me.


I also asked the seller AliExpress (318Bike store) the question. He responded immediately, telling me he would look into it and to let me know if the problem recurred.