ElectricAllWheel Universal E-Bike Battery Downtube Adapter Rail (266mm Adjustable)

Struggling to mount a battery where your frame doesn’t line up? This is the solution.

The ElectricAllWheel Universal Downtube Adapter Rail is designed to give you the flexibility to install or reposition an e-bike battery on frames where standard mounting points don’t match up. Whether you’re adding a second battery, upgrading your setup, or working with a non-standard frame, this rail bridges the gap—literally.

Built for real-world installs, this adapter gives you adjustability, strength, and a clean finished look without drilling or compromising your frame.

What This Solves

• Battery mounts that don’t align with your frame bosses
• Limited downtube mounting options
• Dual battery installations
• Custom or aftermarket battery setups

Key Features

• Universal Downtube Fitment
  Works with most e-bike battery bases including common HaiLong-style (dolphin) mounts
• Adjustable Slotted Design
  Dual slots allow forward/backward positioning to dial in perfect fitment
• Multi-Hole Mounting Pattern
  Evenly spaced threaded holes give maximum flexibility across different frames and battery mounts
• Rigid Aluminum Construction
  Strong, lightweight, and built to handle battery weight and vibration
• Clean Install – No Guesswork
  Designed for straightforward installs with a professional result

Dimensions & Layout

• Total Length: 266mm (10.49”)
• Width: 30mm (1.18”)

Mounting Hole Pattern

• Threaded holes spaced at:
• 20mm (0.79”) increments
• Provides broad compatibility with frame mounting bosses

Adjustment Slots

• Multiple slot sections for flexible positioning:
• 30mm (1.18”)
• 34mm (1.34”)
• 30mm (1.18”)
• Slot Offset:
• Begins approximately 20mm (0.79”) from upper section
• Allows precise front-to-back battery alignment

Edge Spacing

• Initial edge margin: 30mm (1.18”)
• Designed to maintain strength while maximizing usable adjustment range

Perfect For

• Adding a second battery to your e-bike
• Fixing misaligned factory mounting points
• Custom builds and frame modifications
• Upgrading to larger or aftermarket battery packs
• Pairing with ElectricAllWheel dual battery kits

What’s Included

• (1) Universal Downtube Adapter Rail
• Mounting hardware (as shown) 4 - M5*12 Screws (Panhead - Phillips)