LTWOO eR9 Wireless Electronic Shifting & Hydraulic Disc Brake Groupset – 2026 New, Fits Brompton & Foldable Bikes

The all‑new 2026 LTWOO eR9 Groupset brings pro‑level wireless shifting and hydraulic stopping power to your compact ride – designed specifically with foldable bikes, including triple‑fold Brompton, in mind.

Wireless Electronic Shifting (eR9)

• No cables, no clutter – ultra‑clean installation, perfect for tight folding frames.

• 2.4G high‑precision signal with <0.01% packet loss for instant, reliable gear changes.

• One rear derailleur works with 10‑, 11‑, or 12‑speed cassettes – switch modes via the free L‑TWOO APP in one tap.

• 32‑level micro‑adjustment inside the APP for silky‑smooth indexing and zero rubbing.

• Derailleur body: aluminium alloy, 295g – lightweight yet durable.

• Fits cassette: min 11T, max 32T, with mechanical limit stop.

• IPX7 waterproof – handles rain, mud, and even pressure washing.

Hydraulic Disc Brake Calipers (2026 New)

• Flat‑mount & post‑mount compatible – fits most foldable and Brompton front/rear setups.

• 2‑piston aluminium calipers, paired with 140mm rotor (1.8mm thickness, direct‑mount).

• Uses LTWOO “O ONE” mineral oil – reliable, low‑maintenance.

• Hose length: 900mm, ideal for compact frames.

• Weight: front 138g / rear 126g – minimal penalty for maximum stopping power.

Why choose this for your Brompton / foldable?

• Shifter clamp diameter 22.2mm – standard foldable bar size, ready to install.

• Wireless design preserves the clean look and easy folding action.

• Hydraulic brakes give you confident, modulated stopping on city streets or light trails.

Upgrade your foldable today – ride wireless, stop hydraulic, fold perfect.

Key Features (bullet for quick scan):

• ✅ Wireless 2.4G shifting – no cables, fold‑friendly

• ✅ 10/11/12‑speed compatible – one derailleur, all modes

• ✅ APP micro‑adjust (32 levels) – dial in perfect indexing

• ✅ IPX7 waterproof – all‑weather confidence

• ✅ Hydraulic disc brakes (Flat/Post mount) – 140mm rotor ready

• ✅ Ultra‑light: RD 295g, calipers 138/126g

• ✅ 22.2mm shifter clamp – direct fit for Brompton & most foldables

Technical Specs (short table):

Shipping & compatibility note:
Designed for foldable bikes with standard 22.2mm handlebars. For Brompton triple‑fold, check frame/caliper clearance – flat‑mount adapters may be needed (sold separately).