You can find all the replacement parts and components you need for your bike at Escapa.
The Specialized Tarmac SL8 Headset Spacer Kit is an original Specialized replacement part for adjusting the stem height on the Tarmac SL8
Headset transition cap, spacer, and stem cap kit for the Tarmac SL8 when paired with a Roval Rapide stem.
Upper transition cap for the lower Headset race, adapts the SL8 frame to SL8 spacers, height 6.6 mm (1 piece).
Tarmac SL8 aerodynamic plastic headset spacer, 10 mm (3 pieces).
Tarmac SL8 aerodynamic plastic headset spacer, 5 mm (1 piece).
Upper stem transition spacer for Roval Rapide cockpit (1 piece).
Combined SL8 lower headset transition cap / upper steerer transition for Rapide drop-down cockpit configuration, 7.8 mm high (1 piece).
Rapide upper cockpit cap and bolt set available separately—S222500008.