Simplicity is one of the strongest arguments for a 1x gravel setup — one shifter, no front derailleur to trim, and no chain drops when you're bouncing down a washboard descent trying to keep your line. Shimano built the GRX FC-RX600-1 crankset around that logic, using a purpose-designed 40T chainring rather than adapting a mountain bike crank to a drop-bar bike. It slots into the 11-speed GRX ecosystem at the second tier, sitting below the RX810 in the hierarchy but sharing the same asymmetric 110mm BCD so chainrings interchange between the two.

The 40T ring covers the gearing range most gravel riders actually spend time in when paired with an 11-speed cassette in the 11-42T neighborhood — low enough to grind up sustained climbs on a loaded bike, tall enough that you're not immediately spun out on pavement between dirt sections. Shimano's tooth profile alternates heights and shaping to grab the chain positively and keep it seated through rough terrain, which is what lets most riders skip a chain guide entirely unless they're loading up for bikepacking on genuinely chunky routes.

GRX cranks push the chainline out 2.5mm compared to a standard road crank, landing at 49.7mm. That extra clearance is what makes room for the wider tires modern gravel frames swallow — a 42mm or 45mm tire needs the ring nudged outboard to keep the chain from rubbing knobs at the extremes of the cassette. The 151mm Q-factor is slightly wider than road but nowhere near mountain bike territory, keeping your foot stance close to what you're used to on drop bars.