The gt grade carbon tiagra gravel bike 2017 is one of a range of gravel bikes by gt never before has a high tech road bike been so capable on low tech roads the grade is ready for everything from freshly paved switchbacks to the gravel roads and everything in between the grade knows no bounds gt grade carbon tiagra gravel bike features shimano tiagra 2x10 drivetrain tektro hyrd hydraulic calipers stan39s notubes radler disc rims