How good is the s works tarmac di2 in its first season it won two grand tours and a world championshipnot too shabby with its rider first engineered design that ensures peak performance across every size frame coupled with the legendary performance of the dura ace di2 11 speed build kit its no wonder that its the bike of choice for riders like vincenzo nibali and alberto contador if youre looking for the ultimate in complete road bike performance look no further than the s works tarm