Shimano Sora RD-R3000-GS Rear Derailleur - 9 Speed Medium Cage Black Length-420.4 }SRAM DUB English Bottom Bracket

}SRAM DUB English Bottom Bracket - English/BSA 83mm MTB Cannondale Ai Black

and simple pairing SRAM Model ID: BC-KAROO-B1

Hydraulic Bottom Out Damping Adjustments External rebound 2 position (open/firm) HS&LS comp Hydraulic Bottom Out

very durable

the X-10 series has always been a great option

Shimano Sora RD-R3000-GS Rear Derailleur - 9 Speed Medium Cage Black Length-420.4 }SRAM DUB English Bottom BracketShimano Sora RD R3000 Rear DerailleursCompatible with Shimano 9 Speed STI levers Fluoric coated link bushings Aluminum bracket body Painted finish Stainless steel B axle Largest Cog 34 Color Black Rear Der Shifter Compatibility Shimano Road Rear Derailleur Mount Type 10x1 Standard Drivetrain Speeds 9 Chain Wrap Capacity (teeth) 43 Cage Length Medium