Cross-compatibility between the GRX 400 and Tiagra 4700 groups gives you flexibility when building or upgrading a gravel bike without committing to a full groupset swap. The ST-RX400 Dual Control Lever uses the same cable pull ratios as Tiagra, which means you can run GRX levers with Tiagra derailleurs or vice versa depending on what you already have or what deals you find. This left-side lever handles front derailleur shifting and hydraulic braking for 2x10-speed drivetrains, bringing gravel-specific ergonomics to riders who want the GRX experience at an entry-level price point.

The lever body and hood shape match the gravel-specific design across the entire GRX family. Shimano raised the hood head compared to their road levers, which keeps your hands from sliding forward when terrain gets rough or when you transition quickly between hand positions. The brake lever blade features anti-slip texture across its surface, maintaining grip when your gloves are wet or conditions deteriorate. These are the same ergonomic features found on the higher-tier RX600 and RX810 levers, just built into a 10-speed shifting platform instead of 11-speed.

The shifting mechanism borrows internals from Shimano's mountain bike technology, resulting in robust construction that handles the contamination and abuse that come with off-road riding. Front shifts happen with light effort, and the cable actuation provides the tactile feedback that lets you know the shift completed without looking down. The lever includes Optislick stainless steel shift cables and OT-SP41 housing, both designed to reduce friction and resist corrosion from exposure to the elements.... Read More