The Wheels Manufacturing Front Derailleur Shim (31.8 mm to 34.9 mm) is a precision-machined adapter designed to allow a front derailleur sized for a 31.8 mm seat tube to be mounted on bikes with a 34.9 mm seat tube. This robust shim provides a secure, slip-free fit while maintaining proper derailleur alignment for smooth, reliable shifting.
Made from high-quality material and finished for durability, it’s ideal for custom builds, drivetrain upgrades, or when swapping components between frames with different tube diameters.
Features:
- CNC-machined shim for front derailleur fitment adaptation
- Converts 31.8 mm derailleur clamp to 34.9 mm seat tube
- Ensures correct alignment and secure mounting
- Durable construction for long-lasting performance
- Perfect for builds, swaps and upgrades
1-1/8 inch (31.8 mm) to 1-1/4 inch (34.9 mm) front derailleur shim
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The Wheels Manufacturing Front Derailleur Shim (31.8 mm to 34.9 mm) is a precision-machined adapter designed to allow a front derailleur sized for a 31.8 mm seat tube to be mounted on bikes with a 34.9 mm seat tube. This robust shim provides a secure, slip-free fit while maintaining proper derailleur alignment for smooth, reliable shifting.
Made from high-quality material and finished for durability, it’s ideal for custom builds, drivetrain upgrades, or when swapping components between frames with different tube diameters.
Features:
- CNC-machined shim for front derailleur fitment adaptation
- Converts 31.8 mm derailleur clamp to 34.9 mm seat tube
- Ensures correct alignment and secure mounting
- Durable construction for long-lasting performance
- Perfect for builds, swaps and upgrades

