The entry-level model of the Silex line....the 400....is characterized by the aluminum frame with a carbon fork, featuring all mounting options....alongside the grippy 45mm tires, a 2x10 Shimano GRX 400/410 group is used.. ....upgraded with a GRX 600 crankset....hydraulic disc brakes are basically "mandatory"....otherwise, this model wouldn't have made it into our "stock assortment."