Front Derailleur Booster


CNC machined adapter to move a braze-on front derailleur outboard by 7.5mm.

In stock (can be backordered)

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This little bit of CNC machining moves a braze-on front derailleur’s chainline outboard by 7.5mm. It fits bulky SRAM AXS and Shimano Di2 front derailleurs, as well as standard cable-actuated ones. It has features for all the stiffening features of modern front derailleurs, and some set screws to transmit load back to the clamp-on adapter. The bike that inspired this widget is running 27.5x3.1” tires, 46-30 chainrings, and SRAM AXS 2x12 wireless derailleurs; it also has some speedy 29x2.0” tires to justify the 46x10 top gear.

This adapter must be used with a clamp-on braze-on adapter that fits a round tube. When paired with most "road" braze-on adapters and front derailleurs , the resulting chainline will be 51mm. That lines up perfectly with Boost 148mm thru axle rear hubs or 145mm quick release tandem rear hubs.

This product includes the adapter and it's fasteners only. It does not include a front derailleur or frame clamp.


Additional information

Lead time

In stock products ship in 1-2 business days.