Skip to main content

FREE Shipping Now Available on Orders $50+ (excluding oversized items)

Why shop at Mad Dog Cycles? Learn more about our promise here!

Filter By:

  • Show More Brands

  • Show Fewer Brands
  • Show More Model Years
  • Show Fewer Model Years

Derailleurs

$390.00
Riders want a derailleur that shifts on command, whether under climbing load or sprinting to the stage finish. The GX Eagle AXS derailleur gets it done with everything you have come to expect from our AXS connect components. The GX Eagle AXS derailleur is smart enough to protect itself thanks to its incredibly resilient Overload Clutch. Engineered with a variety of rider preferences in mind, it is compatible with our new expanded range 10-52t cassette as well as our 10-50t cassette. Showcasing its lineage from the proven GX Eagle mechanical line, the GX Eagle AXS derailleur is there for one thing: to do the job. Features - AXS enabled componentry software that makes it possible to both program and personalize new SRAM and RockShox components - Overload Clutch protection - Finished with the GX Eagle master colorway - Battery sold separately Specifications - Speeds: 12 - Cage Material: Steel - Pulley Bearings Material: Steel - Max Tooth: 52
$29.99
R10 front derailleurs work with 10-speed Shimano-compatible road shifters. Designed to work with a variety of chainring combinations, these workhorse components will get you rolling again. - Cold-forged aluminum body
$12.99
M21 rear derailleurs are designed to work with 6- and 7-speed Shimano road and mountain shifters. Enjoy the wide variety of bikes you can get going again with M21 rear derailleurs. - Robust composite and steel construction - Compatible with Shimano 6- and 7-speed mountain and road systems - Long cage for double or triple cranksets and 32T max cassette cog - Includes frame hanger attachment for use with older frame designs
$20.99 - $22.99
R8 front derailleurs feature a cold forged aluminum body and are optimized for 7 and 8-speed chains and Shimano-compatible road shifters.
$13.99
- 13-30T - Indexed Adjuster - Weight: 230g-270g
$449.99
Despite its smaller, lighter design, the Shimano Dura-Ace FD-R9250 offers ultra-fast front shifting. - Fast Di2 shifting performance - Smaller, sleeker, lighter - Frontal area is smaller than previous designs to reduce aerodynamic drag - Top gear teeth capacity: 50-55t - 61-66 degree chainstay angle - Includes 1 SD300 port
$28.79 - $35.99 $35.99 Up to 20% Off
Shimano's Acera rear derailleur makes use of advanced designs that make it shift better and last longer. HyperGlide technology results in faster shifting, and Double Servo technology utilizes a double servo-panta mechanism that enables the rear derailleur to track perfectly to each shift and maintain an optimum distance from each sprocket. - Maximum cog size: 34t - Total capacity: 45t - Pulleys: 11t - Chain compatibility: HG 9-speed
$117.99
With an integrated chain stabilizer mechanism, the Shimano GRX derailleur provides a quieter experience while delivering shifting security and precision on mixed terrain. For rides on smooth surfaces, the derailleur features an ON/OFF switch for the chain stabilizer. The RD-RX810 rear derailleur is compatible with road cassettes with a max cog size of 34T. - Adjustable, gravel-tuned chain stabilizer prevents chain slapping and drops - Switch stabilizer ON/OFF to match the terrain - Silent and uninterrupted rear shifting on rough terrain - Low cog: Max. 34T/Min. 30T - High cog: Max. 11T/Min. 11T - Total capacity: 40T - Compatible with current road Dual Control Lever - Maximum front chainring range: 17T
$271.00
The 7-speed X-HORIZON rear derailleur makes shifting smooth and reliable no matter where you ride. Engineered to maintain consistent chain gap across all seven gears, X-HORIZON eliminates vertical movement for faster shifting, reduced shift force, and an end to ghost shifting. Our new, Type-3 roller bearing clutch features a smoother torque curve for a quieter, more consistent operation and feel. The 12-tooth X-SYNC pulley wheel holds the chain in place, reducing bounce and chain slap. Additionally, CAGE LOCK technology makes wheel removal and installation easier than ever. Paired with the X01 DH 7-speed shifter, X-HORIZON forms the backbone of X-ACTUATION technology—and that means completely smooth shifting action. - Updated design of the rear derailleur incorporates our proven X-HORIZON design and new Type-3 roller bearing clutch technology - 12-tooth X-SYNC pulley wheels - Large upper pulley offset automatically adjusts chain gap - Sealed cartridge bearings
$650.00
The XX Eagle T-Type AXS™ 12-Speed rear derailleur foundationally changes the relationship between cassette and derailleur. Engineered as integrated, interdependent transmission components, the T-Type derailleur mounts around the wheel axle itself, contacting the cassette directly with a first-of-its-kind Hangerless Interface. Its game-changing Full Mount attachment method creates a far stronger connection and grips both sides of the frame. This XX T-Type rear derailleur features the same intuitive pairing and set-up procedure as Eagle AXS™ derailleurs. - Tucked-in profile houses replaceable skid plates that enhances dependability in high-pressure racing environments - To further its performance, the lower pulley called "Magic Wheel" keeps spinning if an object becomes lodged - Features an overload clutch, accommodates common maintenance and features that real world riders really appreciate - Exceptional shifting performance and unprecedented strength - Aluminum cage - Battery Not Included
$550.00
Whether on the starting line or not, the X0 Eagle T-Type 12-Speed rear derailleur brings competition-tested prowess to riders who let their riding prove everything. Engineered as integrated and interdependent transmission components, the X0 T-Type derailleur mounts around the wheel axle itself, contacting the cassette directly with a first-of-its-kind Hangerless Interface. This foundationally changes the entire relationship between cassette and derailleur. Beyond that, its Full Mount attachment method creates a far stronger connection that grips both sides of the frame. These X0 T-Type rear derailleur features the same intuitive pairing and set-up procedure as our Eagle AXS™ derailleurs - Competition proven strength and reliability - X0 Eagle derailleur is especially robust, allowing for common maintenance that serious riders demand - Features an overload clutch that boosts resiliency and a tucked-in profile that houses protection covers on the B-knuckle and outer link that are fully replaceable - Aluminum cage - Battery Not Included
$34.99
Exceptional front shifting performance for large-wheel mountain bikes. Tackle trails with this Shimano CUES FD-U6000 front derailleur's smooth and quiet shifting. It is compatible with 2x11 and 2x10-speed drivetrains. - Smooth and quiet shifting on and off the trail - Provides and extra-wide range with front double - Offers wider tire clearance - Works with 48.8 - 51.8mm chainlines - 64-69 degree chainstay angle
$34.99
Exceptional front shifting performance for large-wheel mountain bikes. Tackle trails with this Shimano CUES FD-U6000 front derailleur's smooth and quiet shifting. It is compatible with 2x11 and 2x10-speed drivetrains. - Smooth and quiet shifting on and off the trail - Provides and extra-wide range with front double - Offers wider tire clearance - Works with 48.8 - 51.8mm chainlines - 64-69 degree chainstay angle
$44.99
- Model Number: RD-R3000-GS - Series: SORA - Maximum Sprocket: 34T - Minimum Sprocket: 11T - Maximum Front Difference: 20T - Total Capacity: 43T
$639.95 - $764.00 $764.00 Up to 16% Off
The heart of the connected cadre. The SRAM RED eTap AXS rear derailleur is AXS enabled for easy personalization and designed for both 1x and 2x systems. Advanced chain management keeps it silent and secure no matter the terrain. The derailleur also comes with faster pulleys, bearings, motors, and signals, improving speed in every way. - SRAM AXS-enabled for easy personalization - Orbit chain management technology keeps drivetrain quiet and secure - A single rear derailleur for all gearing combinations, including 1x and 2x - Improved motor and signal travel for faster shifting - Larger X-SYNC pulleys and ceramic bearings for increased durability and efficiency - Compatible with existing eTap batteries - Battery sold separately
$50.99 - $55.99
Shimano's 105 Rear Derailleur delivers high-end function with upscale looks. With a body of light, durable cold-forged aluminum in Shimano's wide-pivot design with their light-action spring, rear shifting is practically effortless and always super smooth. The top pulley stays a uniform distance from each cassette cog ensuring that every shift resonates with the plunk of exact gear engagement.
$12.99
M21 rear derailleurs are designed to work with 6- and 7-speed Shimano road and mountain shifters. Enjoy the wide variety of bikes you can get going again with M21 rear derailleurs. - Robust composite and steel construction - Compatible with Shimano 6- and 7-speed mountain and road systems
$84.95
- Rider Tuned For Sharp And Silky Shifts - 20% Light Shifting Operation - New Shadow Design With Optimized Slant Angle - Optislick New Shift Cable With New Hyper Low-Friction Coating Technology - Chain Stability Improved - New Shadow Design With Optimized Slant Angle For Stable Gear Position - Efficient Shifting And Smoother Driving - Efficient Pulley Teeth Design - Increased Traction Range For Long-Travel And Active Rear Suspension - Series : SLX: SLX - Maximum Sprocket : 42T(2x11-speed) or 46T(1x11-speed) - Minimum Sprocket : 11T: 34-38T - Front Difference : 10T: 48.8 - Total Capacity : 41T: 66-69 - Average Weight : 323g: 145.6g
$21.99
Shimano FD-M2000 front derailleurs feature Mega Lite and HyperGlide technologies for smooth and easy operation. They're a perfect replacement for your 3 x 9 drivetrain.
$56.99 - $61.99
Shimano 105 7000-series components offer much of the same technology and functionality as their top-level 11-speed drivetrains at a more budget-friendly price point. The RD-R7000 rear derailleur provides stable shifting performance and wide-range compatibility in two different cage lengths. The Shadow RD design limits the amount the derailleur sticks out from the side of the bike, reducing the risk of it making contact with objects and bending. - Maximum cog size: 30t (SS) / 34t (GS) - Total capacity: 35t (SS) / 39t (GS) - Pulleys: 11t - Chain compatibility: HG-EV 11-speed/HG-X11 - Direct mount compatible
$29.59 - $30.99 $30.99 - $36.99 Up to 20% Off
Shimano's 105 Braze-On Front Derailleur sports a cold forged-aluminum body with Shimano's extra wide-pivot design for lightning-quick and super-smooth shifts. The steel cage ensures excellent durability.
$27.49
Shimano Altus RD-M370 Rear Derailleurs 9-Speed 11t upper and lower pulleys
$39.99
- 2:1 actuation ratio compatible with most Shimano 3x9sp drivetrains - Aluminum and steel construction with 11-tooth pulleys barrel adjuster
$71.00
SRAM's GX 2x10 rear derailleur provides incredible shifting speed and precision. Exact Actuation technology eliminates slop and shifting variation. Roller Bearing Clutch technology delivers maximum drivetrain stability—even through the most punishing terrain. And with Cage Lock technology, wheel removal and installation are easier than ever.
$54.99 - $59.99
Shimano Ultegra R8000 front derailleur. - Lighter front shifting operation - Link construction matches the force curve of the hand more naturally to reduce effort at the end of shifting - 100% perfect setting - New link construction allows for more flexible cable routing design - TL-FD68 and turning converter is not required in assembly - Easy and precise setting - Now possible to adjust cable tension on FD without specialized tools - Redesigned to fit wider gear pitch without sacrificing shifting performance - Shorter length of rear center (410mm) with O.L.D. 135mm - Model Number: FD-R8000-B - Series: Ultegra - Top Gear Teeth: 46-53T - Chain Stay Angle: 61-66 - Chain Line: 43.5 - Average Weight: 106 grams
$239.99
Shimano Ultegra R8050 Di2 front derailleur. - Quick and smooth front shifting under high pedaling torque - Programmed control of chain guide - Shimano Synchronized shift - Full and semi synchronized shifting program - Redesigned to fit wider gear pitch without sacrificing shifting - Shorter length of rear center (410mm) with O.L.D. 135mm - System communication with rear derailleur, Programmed control of chainguide works for minimal chance of chain drop - Top Gear Teeth: 46-53T - Chain Stay Angle: 61-66 - Chain Line: 43.5 - Average Weight: 132 grams
$51.99
Shimano's Tiagra Rear Derailleur SS (10-speed) is sleek, balanced and consistent. The Tiagra 4700 series provides serious entry-level riding performance with trickle-down technology from the top shelf Dura Ace line. - Model Number: RD-4700-SS - Series: Tiagra - Cassette Compatibility: 10-speed - Maximum Sprocket: low sprocket: 28T / top sprocket: 14T - Minimum Sprocket: low sprocket: 25T / top sprocket: 11T - Maximum Front Difference: 16T - Total Capacity: 33T
$34.99
The Shimano GRX RX400 front derailleur offers lighter front shifting operation and easier setup thanks to the new link construction and integrated cable tensioner. It features a 2.5mm outboard chain line design to allow wider tire clearance for mixed-terrain riding. - Ergonomic power curve - Integrated cable tension adjustment - Natural stroke feeling - Chainline +2.5 mm vs. conventional road FD - Compatible with up to 42 mm tires - More cable routing options - Lighter front shifting - Wider tire clearance - Precise and easy front derailleur adjustment