The LTWOO eRX/eR9 electronic groupset offers impressive value with good shifting and braking performance when it works, but reliability issues, poor customer support, and inconsistent quality control plague many units, especially early versions. Later versions (V3) have addressed some problems, yet concerns about water resistance, battery holder design, and long-term durability persist. It is best suited for confident DIY enthusiasts willing to troubleshoot and accept risks.
Pros
- Excellent value for money: costs significantly less than Shimano 105 Di2 or SRAM, with complete groupsets often around $300-$500 USD or £350-£600.123
- Good shifting performance when properly tuned, with rear shifting described as fast, crisp, and comparable to Shimano Di2; front shifting improved in later versions.456
- Flexible compatibility: works with various cassettes (beyond 32T with mods), cranksets, and mineral oil brake calipers from other brands; Shimano cassettes and chains significantly improve shifting.78
- Ergonomic shifters with comfortable hoods, appreciated by users with medium hands; better than old SRAM eTap according to some.27
- Replaceable standard 14500 batteries allow easy swaps and avoid proprietary battery issues; battery life is good (approximately 900 km per charge, claimed up to 3000 km).497
- Hydraulic disc brakes provide powerful bite and are easy to bleed with mineral oil; no rebleeding needed after initial installation.42
- App offers extensive customization: can set 10/11/12-speed, micro-adjust individual sprockets, and update firmware; auto-trimming added in June 2026.287
- Lightweight options: ERX components are lighter than Shimano 105 Di2 equivalents (e.g., ERX RD 289g vs 105 Di2 RD 301g).75
- Some users report no issues after thousands of kilometers, with V3 groupsets working reliably and being considered solid.71
- LTWOO eRX TT groupset was used by a professional team at a Tour de France Femmes stage, indicating some pro-level adoption.7
Cons
- Poor reliability and high failure rates, especially early versions (V1/V2), with rear derailleurs dying from water ingress, battery connection issues, and front derailleur failures.1074
- Very poor customer support and warranty service from LTWOO, with sellers often unhelpful or ghosting customers; spare parts availability is extremely poor and parts may be discontinued within a year.74
- Water sealing issues persist even in V3/ER7 versions, causing rear derailleur failure after rain; users recommend dielectric grease or liquid electrical tape for protection.78
- Groupset can suddenly become unresponsive (brick) mid-ride, often due to battery holder slipping inside the seatpost triggering BMS protection; requires connecting a charger to wake up.7
- Front shifting is noisy, clunky, and slow compared to Shimano Dura-Ace, with occasional hesitation and chain drops in earlier versions.254
- Shifter buttons have light action causing accidental gear changes over bumps, and side-to-side play; early versions had mushy buttons.1107
- Brake calipers use a non-standard mount requiring ugly adapters for most flat mount frames; bleeding can be problematic requiring specific techniques.27
- Setup instructions are less documented than major brands, app initially in Chinese, and lack of support from bike shops; only suitable for confident self-installers.23
Key Facts
- Weight: rear derailleur 285-289g, front derailleur 138-139g, shifters 444-477g (pair), brake calipers 300g (pair, V3), battery 64g; total system weight varies by version.1057
- Uses standard 14500 800mAh 3.7V batteries; non-standard capacities (1000mAh, 1500mAh) can cause failure to wake up or erratic behavior.78
- Semi-wireless design: shifters are wireless (2032 coin cell), front and rear derailleurs are hardwired to a battery in the seatpost.197
- Compatible with cassettes beyond 32T (e.g., 34T, 36T) with pulley wheel swaps or OSPW cage; some users run 11-42T with 46/30 chainrings.71
- Hydraulic brakes use mineral oil and are compatible with Shimano/other calipers and standard pads (e.g., Galfer).710
- V3 version features USB-C charging on the front derailleur only (no rear derailleur port); does not support USB-C to USB-C (PD) cables, only USB-A to USB-C or OTG adapter.71
- App allows fine-tuning each sprocket individually, switching between 10/11/12-speed, and firmware updates; auto-trimming added via app update (June 2026) but can cause chain drops for some users.786
- V3 is not backwards compatible with V1/V2 components; V3 shifters cannot pair with V2 groupsets.7
Sources
- 1Miller_cycling7,000km with Ltwoo eRX/9 Electronic Groupset: is it any good?
- 2Tom Bowers CyclingI Ditched Dura Ace for Ltwoo ERX. Was It a Mistake?
- 3GC Performance12 SPEED CHINESE ELECTRONIC GROUPSET (RIDE REVIEW) *eRX L-TWOO*
- 4Trace Velo2 sources
- 5Local Alien / CLIFFL-Twoo eRX Roadbike Groupset Review Install / Chinese Electronic Groupset Ltwoo eRX eR9
- 6Klein ConceptDoes L-Twoo eRX really outperform Di2 Dura Ace? Battle of Budget vs premium electronic shifting.
- 7ChinertownLTWOO ER9 & ERX - Electronic groepsets
- 8Веломастерская love.bikeLTWOO ERX - электронная группа для любой кассеты!
- 9David Arthur - Just Ride BikesL-Twoo eRX Impressions: a genuine Shimano rival?
- 10China Cycling2 sources
Reviews & Ratings
09:07The reviewer tests the new LTWOO eRX groupset, highlighting improvements in front shifting compared to the previous version. They find the rear derailleur to be excellent and customizable, while the front derailleur, though not as flawless as Shimano, is reliable and close in performance. The brakes are adequate but less refined than Shimano. Overall, the groupset is praised for its value and innovation.
17:19The reviewer discusses the LTWOO eRX 2x12s/2x11s Road Electronic Hydraulic Disc Brake Groupset, highlighting its unique feature of adjustable derailleur settings per cassette star, which allows for compatibility with non-standard cassettes. They note the groupset's affordable price and potential for customization, but also point out several drawbacks including software issues, lack of waterproofing, and a weak front derailleur design.
08:57The reviewer provides first impressions of the LTWOO eRX electronic groupset, highlighting its competitive pricing compared to Shimano 105 Di2, good shifting performance, ergonomic levers, and hydraulic disc brakes, while noting some drawbacks such as bulky front derailleur and lack of complete groupset components.
20:04The reviewer discusses the LTWOO eRX electronic groupset, highlighting differences between an early version he purchased and a newer version sent by the company. He experienced initial issues with battery disconnections, which were fixed by a redesigned battery. He praises the groupset's performance, value, and rain resistance, but notes some ergonomic and software quirks.
11:50The reviewer introduces the LTWOO eRX 2x12s/2x11s Road Electronic Hydraulic Disc Brake Groupset, highlighting a new 'blue edition' with updated aesthetics and minor weight reductions. They compare it to the previous version, noting changes in derailleur and shifter designs, and a significant weight drop in the brake calipers due to a monoblock construction. The reviewer is cautiously optimistic about reliability improvements but remains skeptical based on past issues.
01:53:08The reviewer discusses the LTWOO V3 eRX eR9 electronic groupset based on experiences from three YouTubers (China Cycling, GC Performance, and Trace Fellow). They note that when it works, the groupset performs well with good shifting, braking, and ergonomics, but all three reviewers experienced reliability issues including waterproofing problems, battery connection failures, and front derailleur malfunctions. The reviewer cannot recommend it for everyday consumers due to these reliability concerns.
21:22The reviewer discusses the LTWOO eRX eR9 electronic groupset as a runner-up for the 'Best Innovation' award. They highlight its innovative approach to navigating patent challenges in the electronic groupset market, particularly noting the creative solutions like hiding the LED indicators. However, they also mention it had some teething problems, which might be why it didn't win the 'Best Product' category. Despite these issues, the reviewer expresses faith in LTWOO's ability to resolve them and improve the product.
55:28The reviewer briefly mentions the LTWOO eRX eR9 2x12s / 2x11s Electronic Groupset, Road Electronic Groupset, Replaceable battery, APP programming but does not provide detailed analysis.
55:28The reviewer briefly mentions the L-TWOO 2025 eRX Road Electronic Hydraulic Disc Brake Groupset 2x10-12 SPEED but does not provide detailed analysis.
13:42The reviewer discusses a failure with the LTWOO eRX electronic groupset where the front derailleur stopped working after being unplugged and reconnected. Through systematic swapping of components, they determined the issue was with the rear derailleur, which houses the system's brains. Despite disassembly, no hardware fault was found, leading them to suspect a software issue. They replaced the rear derailleur and the groupset worked again, but they remain uncertain about its long-term reliability.
09:37The reviewer discusses their experience with the LTWOO eRX electronic road bike groupset, specifically version 1.0, over six months and approximately 2,000 km. They highlight its performance, durability, and recent updates in version 2.0. The reviewer initially faced some early issues but found the groupset to be largely flawless after resolving them. They praise its shifting, braking performance, ergonomics, and companion app, while also noting some early teething problems that were addressed in later versions.
58:05The reviewer briefly mentions the LTWOO eRX eR9 2x12s / 2x11s Electronic Groupset, Road Electronic Groupset, Replaceable battery, APP programming but does not provide detailed analysis.
17:44The reviewer briefly mentions the L-TWOO 2025 eRX Road Electronic Hydraulic Disc Brake Groupset 2x10-12 SPEED but does not provide detailed analysis.
09:44The reviewer compares the LTWOO eRX 2x12s/2x11s Road Electronic Hydraulic Disc Brake Groupset to Shimano Dura-Ace Di2, focusing on shifting performance. They find the shifting smooth and similar, noting a minor hiccup but overall minimal difference. They also discuss the absence of auto-trim due to patent issues, but mention a manual trim via double-click. They have not experienced the reported sleep issue on the rear derailleur, possibly due to firmware updates. They are impressed with the value given the price difference.
08:46The reviewer provides a long-term review of the LTWOO V3 eRX/eR9 electronic groupset after approximately 7,000 kilometers of use. He describes it as a semi-wireless Chinese groupset with shifters communicating wirelessly to derailleurs that are hardwired to a seatpost battery. Overall, his experience has been very positive, finding it well-made, functional, and enjoyable to use, though he notes some minor issues.
22:30The reviewer discusses the LTWOO V3 eRX eR9 electronic groupset as part of a broader overview of Chinese cycling components. He mentions it's an upgrade to the IR9 with some carbon elements, available for around 500-600€ for almost the entire groupset via AliExpress, and compares its feel to Shimano 105. He notes it uses a battery in the seatpost and has app control capability.
22:55The reviewer purchased and installed the LTWOO ERX (referred to as L2, L2 V3, L2 ERX, and ERX) electronic groupset on a winter training bike, replacing Dura Ace Di2. They tested it for approximately 5 months. The reviewer states the rear shifting is fast, reliable, and crisp, comparable to other electronic groupsets. The front shifting is noted as noisy, clunky, and slow, reminiscent of older generation products. The app offers extensive customization, including selecting 11 or 12-speed operation and micro-adjusting individual sprockets, but the initial setup was challenging with a default Chinese language setting. The groupset uses a semi-wireless design with USB-C charging via the front mech, which is praised, and battery life is reported as good. The brakes require non-standard adapters for flat mount frames, which the reviewer dislikes. The groupset is significantly heavier than Dura Ace, comparable to Shimano 105. The price is a major advantage, coming in considerably cheaper than Shimano 105 Di2 when factoring in additional drivetrain components. The reviewer concludes it is a solid competitor to 105 Di2 for tinkerers and self-builders, but has compromises compared to top-tier groupsets.
11:33The reviewer installed the LTWOO eRX electronic groupset on a bike build and tested it over approximately 100 kilometers. He found the shifting to be 'buttery smooth' and was impressed with the overall performance, describing it as giving a 'premium experience'.
55:19The reviewer discusses their experience with the LTWOO eRX eR9 2x12s/2x11s Electronic Groupset, highlighting both its potential and significant issues. They initially chose it for its unique features but ultimately replaced it due to performance problems.
The LTWOO eRX/eR9 (V3) is a Chinese electronic road groupset known for its low price, typically $300-$500 USD on AliExpress with coupons, though recent pricing has been inconsistent (e.g., 80 Designer Store charging 530€ + 114€ shipping for an ER9 without brakes). It features 11/12-speed compatibility, hydraulic disc brakes using mineral oil, and replaceable 14500 batteries. Key attributes include: price around $300-$500, weight varies by model (eR9 alloy, eRX carbon; eR7 is a mid-tier option), and it uses standard road standards with compatibility for various cassettes (up to 34T with modifications, and some users run 11-42T with 46/30 chainrings) and cranksets. The V3 version introduced USB-C charging on the front derailleur, improved shift buttons, and better water sealing, though reliability and warranty support remain common concerns. A recurring issue is the groupset suddenly becoming unresponsive mid-ride, requiring a brief charger connection to 'wake up' the system. This is often caused by the battery holder slipping inside the seatpost, triggering BMS protection. Users recommend securing the battery holder with rubber mounts or bubble wrap. Additionally, the groupset does not support USB-C to USB-C (PD) charging; only USB-A to USB-C cables or OTG adapters work. Shifting performance is significantly improved with Shimano cassettes and chains, while aftermarket Chinese cassettes may cause hesitation. The groupset continues to mature, with newer versions featuring lighter brake calipers (about 70g lighter per caliper) and improved compatibility. A major recent update (June 2026) reintroduced auto-trimming for the front derailleur, which automatically adjusts to prevent chain rub and works on many firmware versions via app update. However, auto-trim has mixed results: some users find it works great, while others report aggressive trimming causing chain drops, especially in big chainring/largest cog combinations. The 'First Aid Kit' option in the app is a new but undocumented feature. Users report ongoing challenges: non-standard batteries (e.g., 1000mAh or 1500mAh) can cause failure to wake up; the battery holder can break when inserting tight batteries, and some holders crack even with the smallest 14500 cells; water ingress can still occur in V3/ER7 versions, causing rear derailleur failure after rain; and firmware updates can still brick components. Customer support remains poor, with reports of LTWOO representatives becoming defensive when criticized, and spare parts availability is extremely poor—LTWOO may discontinue production of parts (e.g., shifter housings) within a year of version release, leaving customers unable to repair. V3 is not backwards compatible with V1/V2 components. Some users report chain skipping on specific gears under load, requiring fine micro-adjustment. Gear protection may no longer prevent shifting to the small chainring while in the 11 and 12 cogs after the auto-trim reintroduction. The new fully wireless eGR groupset with integrated battery is not yet released as of mid-2026. Despite these issues, the groupset offers excellent value for DIY enthusiasts willing to troubleshoot, and some users report no problems after thousands of kilometers. LTWOO eRX TT was used by a professional team at a Tour de France Femmes stage, indicating some pro-level adoption. The eR7 rear derailleur exists in at least two versions (one Shadow-style, one with short connection), which can cause confusion. Overall, the groupset is a viable budget option for those who accept the risks and are willing to secure the battery holder, use Shimano cassettes/chains, and potentially seal cables with silicone or liquid electrical tape.
AI Summary
Pros
- Excellent value for money, offering electronic shifting at a fraction of Shimano/SRAM prices.
- Good shifting performance and speed when properly tuned, with crisp and fast shifts.
- Flexible compatibility: works with various cassettes (beyond 32T with mods), cranksets, and mineral oil brake calipers from other brands.
more pros in the review
Cons
- Poor reliability and high failure rates, especially for early versions (V1/V2), with rear derailleurs dying from water ingress or other issues.
- Very poor customer support and warranty service from LTWOO, with sellers often unhelpful or ghosting customers.
- Water sealing issues, particularly in V1/V2 where charging ports allow water ingress, leading to failures.
more cons in the review
Key Points
- V3 version features USB-C charging on FD (no RD port), improved buttons, and better sealing.
- Compatible with cassettes beyond 32T (e.g., 34T, 36T) with pulley wheel swaps or OSPW cage.
- Uses standard 14500 800mAh 3.7V batteries. Non-standard capacities may cause issues.
more key points in the review
Where to Buy

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LTWOO eRX Road Electronic Groupset, eRX 2x12s / 2x11s elektronische Gruppe, ERX austauschbare Batterie, APP-Programmierung - AliExpress 18


2026 New LTWOO V3 ERX 2x12s / 2x11s Electronic Groupset, Road Electronic Groupset, Replaceable Battery, APP Programming


L-TWOO eRX Road Electronic Hydraulic Disc Brake Groupset


LTWOO V3 eRX eR9 2x12s / 2x11s Electronic Groupset, Road Electronic Groupset, Replaceable battery, APP programming

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