Wilier gtr sl endurance ultegra di2 road bikethe wilier gtr sl endurance ultegra di2 road bike is stiffer more comfortable lighter and more aerodynamic than previous generations its so good that it performs like wiliers top of the line models the geometry and clinincal engineering perform superbly and the lightweight frame at 990g in the medium size certainly helpswilier equipped this high end bike with a carbon fork that has a tapered 1 18 to 1 steerer which provides strong and