Ultegra Di2 RD-R8150 Rear Derailleur Groupsets while the 55mm chain line

while the 55mm chain line offers maximum frame compatibility

Goodbye range anxiety

5 hr runtime in High Steady mode

meaning 18 engagement points per click

Includes 3 DART heads

Ultegra Di2 RD-R8150 Rear Derailleur Groupsets while the 55mm chain lineSHIMANO ULTEGRA Di2 Rear derailleur SHIMANO SHADOW RD 2x12 speed Now simplified with a single derailleur cage length, the new 12 speed Shimano ULTEGRA R8150 rear derailleur packs our fastest, most precise shifting into a more approachable option. With our fastest, most accurate shifting, the new 12 speed ULTEGRA R8150 rear derailleur is more versatile than ever thanks to a single cage length option that is compatible with 28 34T low sprockets. Our