REAR DERAILLEUR, RD-R9150, DURA-ACE DI2, SS 11-SPEED, SHADOW DESIGN, DIRECT ATTACHMENTThe Shimano Dura Ace Di2 RD R9150 Rear Derailleur is a wholesale re design of the fabled rear mech. The biggest practical improvement is that cage and pulley wheels have been moved to accommodate cassettes with a 30 tooth cog. But thats really the icing on the cake. The rest of the derailleur is much improved as well. The first thing Shimano did was change the pivot point. Rather than being on the derailleur hanger, its below and behind it. This helps

Zipp’s 303 S Tubeless Disc Brake wheelset provides today’s cyclists the versatility they demand with the speed they crave

68mm American Bottom Bracket

2 cups with CeramicSpeed Bearings installed

High- and low-speed compression and high- and low-speed rebound adjustment

(look at CX category)

Bigger 13T pulley

Designed in collaboration with @oneway_corey and manufactured by Mafia Bikes

and 46-36T chainrings and 165

chunky descents

It gives out 300 lumens in the warning flashing mode and works with Garmin/Wahoo/Bryton computer mounts to keep your handlebar clean

Includes alloy top cap w/bolt

For cooler climates or seasons