Paul Components Melvin Chain Tensioner. Converts frames for single speed use. Long enough for a Dingle-setup, (2 rings, one cog) 20T max. - The Melvin uses two pulleys, just like a rear derailleur, which gives it 20 teeth of chain wrap - Will work with multiple front chain rings while maintaining proper chain tension - The pulleys are made of extruded and machined aluminum and have sealed bearings for durability - Pulleys are 2.25mm thick at the tooth which fits inside most narrow 6 through 9 speed chains, and the pulley cage is wide enough to allow 1/8? single speed chains as well - Long enough for a Dingle-setup, (2 rings, one cog) 20T max - Do not use with a coaster brake or fixed gear - Includes Paul's own Sealed Bearing Pulleys

Campagnolo's Veloce Rear Derailleur uses an advanced-parallelogram design that assures precise and quick shifting. The aluminum construction reduces weight and boosts strength for crisp gear changes. Plus, the pulleys are made from a special material that renders the drivetrain nearly silent.

The GX Eagle Transmission derailleur is a lesser version of nothing. It delivers everything an Eagle Transmission derailleur possibly can, and then some. It features a revised battery position and a reconfigured gearbox to better protect itself from impacts. To maintain crisp shifting and striking appearance throughout its entire lifespan, hard-chargers can replace both its protective skid plates and two-piece outer link, if needed, making this the most repairable derailleur we’ve ever made. It also features the first ever tool-free cage and clutch assembly – so it’s both removable and upgradable too. With a steel inner cage that adds even more robustness, it’s been built for riders of the real world. Just like all Eagle Transmission derailleurs, it’s been engineered with a first-of-its-kind Hangerless Interface, mounting around the wheel axle itself and making direct contact with the cassette with no hanger required. The new transmission derailleurs feature the same intuitive pairing and set-up procedure as our Eagle AXS derailleurs. The revolutionary Full Mount attachment method creates a far stronger connection because it grips both sides of the frame. Let the record show that the GX Eagle Transmission derailleur plays second fiddle to nothing. It’s all in for all day. - Revised battery position, reconfigured gearbox, replaceable skid plates and outer link, tool-free cage and clutch - Install and pair via the reliable and familiar standard AXS set-up and pairing procedure - Hangerless Interface, Full Mount attachment method - Radically clear setup process, no adjustment required - AXS battery and Pod controller available separately

The Campagnolo EKAR Rear Derailleur is designed for the 1x13-speed EKARndrivetrain with a gravel-orientated performance & build. - 2D parallelogram trajectory offers precise mechanical movement for 13 sprockets - High grade polymer pulley wheels (12T upper, 14T lower) allow for smooth chain running and secure retention - Carbon fiber-reinforced polyamide and anodized 7075 and 6082 alloys are lightweight, strong, and durable - Stainless steel bolts for strength and long-term resilience on gravel - Includes clutch lock for easy wheel removal Specifications: - Largest Cog: 44 - Rear Derailleur Mount Type: 10x1 Standard - Chain Wrap Capacity (teeth): 34 - Cage Length: Medium - Rear Der/Shifter Compatibility: Campy EKAR - Drivetrain Speeds: 13 - Weight: 275g

The Super Record 12-Speed rear derailleur combines the highest quality materials for exceptional weight and unparalleled performance. The unidirectional carbon fiber front rocker arm reduces weight, with an innovative shape that envelopes the cassette better, thanks to 3D Embrace technology, creating a double effect: allowing the chain to maintain optimum traction at all times, thus increasing the speed, power and precision of shifting. - Carbon fiber-reinforced construction, to increase strength while keeping weight to a minimum - Optimized spring return for constant chain tension - Adjustment of the initial rear derailleur position - Removable pivot on the upper body - Optimized to work with cassettes from 11 to 34 teeth Specifications: - Largest Cog: 34 - Rear Derailleur Mount Type: 10x1 Standard - Chain Wrap Capacity (teeth): 37 - Cage Length: Medium - Rear Der/Shifter Compatibility: Campy 12-Speed Chorus/Record/Super Record 2019+ - Drivetrain Speeds: 12

The XX SL 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 SL T-Type rear derailleur features the same intuitive pairing and set-up procedure as Eagle AXS™ derailleurs. - Features an overload clutch and a tucked-in profile, removing all but what’s needed - Accommodates common maintenance and to further its race-day performance, comes with a lower pulley called "Magic Wheel" that keeps spinning if an object becomes lodged - Features a carbon cage, a replaceable outer link and b-knuckle cover for lightweight and easy maintenence - Battery Not Included

The Box One Prime 9 Rear Derailleur takes the advantages of our legacy 9-speed drive-train but adds the advancements of a modern 1 by; a fully adjustable Tri-Pack Clutch, and an x-wide cage optimized for an 11-50T cassette. Forged construction steps up the durability and performance to an unparalleled level. Suited for the most demanding terrain.

• Converts Braze-on front Derailleurs to clamp on • Lightweight forged alloy • Weight: 28g

The Box Three Rear Derailleur simplifies the features found on the Prime 9 Box One and Two rear derailleurs making for a fully featured wallet friendly rear derailleur. Including a Limited Slip Clutch, Sealed bearing pulleys and a solid construction Box Three Rear derailleurs are compatible with 11-46 and 11-50t derailleurs making it one of the most versatile derailleur offerings for Prime 9.

It takes a degree of passion for the sport that can’t be faked to fully appreciate SRAM RED. It was created to blur the boundaries between machine and athlete. The SRAM RED rear derailleur was designed with Exact Actuation technology for precise, efficient shifting. Carbon fiber, titanium, and ceramic bearings complete the spec. The result adds to its legacy as the heart of the purest groupset for the pursuit of cycling excellence. - SRAM 11-speed compatible - WiFLi option - Carbon cages, carbon inner links, titanium hardware - Exact Actuation shifting provides fast and accurate shifts - Silent shifting with optimized AeroGlide pulleys, ceramic bearings - Spring-fixed barrel adjuster - Chain pulley cage adds precise chain management - Titanium pinch bolt keeps a low profile while minimizing weight - Speeds: 11 - Material: Carbon cages, Carbon inner links, Aero designed titanium hardware - Weight: 145 grams short cage), 165 grams (mid cage) - Compatibility: SRAM RED & Force Rear Shift-Brake levers, SRAM R2C Aero SL-1190 shifters, - SRAM R2C Aero SL-1150 shifters, SRAM 900 Aero brake levers, SRAM 500 Aero brake levers - Finish: Falcon grey & black anodized - Tech Highlights: AeroGlide Pulleys, Exact Actuation - Largest Cog (teeth): 28 (short cage) 32 (WiFli Medium Cage)

SRAM's Rival 22 Front Derailleur delivers precision shifting with YAW technology. The steel cage with aluminum links ensures strength and durability. • Yaw cage rotates in line with chain, improving the shifting speed and precision while eliminating the need for shifter trim • Integrated chain spotter protects your frame, installs and adjusts independently of the derailleur itself • Precision alignment markings on the cage • Clamp: braze-on • Weight: 89g with Chain Spotter

With an integrated chain stabilizer mechanism, the Shimano GRX derailleur provides a quieter experience along with shifting security and precision on mixed terrain. For rides on smooth surfaces, the derailleur features and ON/OFF switch for the chain stabilizer. The RD-RX815 Di2 version offers the digital precision of Shimano electronic shifting with synchronization and 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 - Total capacity: 38T - Smooth and reliable mixed surface shifting - Compatible with current road Dual Control Lever - Maximum front difference: 17T - High cog: Max. 11T/Min. 11T - Low cog: Max. 34T/Min. 30T

With an integrated chain stabilizer mechanism, the Shimano GRX derailleur provides a quieter experience and shifting security and precision on mixed terrain. For rides on smooth surfaces, the derailleur features and ON/OFF switch for the chain tensioner. - Adjustable chain stabilizer prevents chain slapping and drops - Switch stabilizer ON/OFF to match the terrain - Gravel-tuned clutch tension - Maximum front T difference: 16T - Silent and uninterrupted rear shifting on rough terrain - Low cog: Max. 36T/Min. 30T - High cog: Max. 11T/Min. 11T - Total capacity: 41T - Smooth and reliable mixed-surface shifting - Compatible with current 10s road DUAL CONTROL LEVER - Compatible with wide-range front gearing

- Upper pulley has larger teeth for increased chain control

Ultegra RX brings Shimano's pioneering chain stabilizing technology to road cycling, delivering smooth and precise shifting over technical terrain. It expands road bike capabilities, inspiring confidence on any surface and drives the evolution of road cycling to include greater elements of adventure. No longer is the road bike narrowly defined. Shimano Ultegra RX broadens the notion of drop bar riding and emboldens cyclist to explore further. - Chain Stabilizer mechanism adopted from MTB design - Stabilizer ON/OFF switch - Compatible with current road dual control lever - Shadow RD technology - Direct mount compatible - Maximum cog size: 34t - Total capacity: 39t

Shimano Side Swing front derailleurs feature improved cable routing for smooth and efficient front shifting effort and increased clearance for larger tires and shorter chainstays. - Optimal front system for internal cable routing - Enhanced maneuverability with plus-sized tires - Increased shifting efficiency and light and smooth operation force - D, E, M type mounts are available - M type mount requires 34.9mm adapter

- 10/11 Speed compatible - MTB: Direct attachment (Shadow) - 42T Max Low Sprocket - 11T Min top Sprocket

Sleek, balanced and consistent. Shimano's Tiagra 4700 series front derailleur provides serious entry-level riding performance with trickle-down technology from the top shelf Dura Ace line. - Model Number: FD-4700 - Series: Tiagra - Cassette Compatibility: 10-speed - Top Gear Teeth: 53T - Maximum Capacity: 16T - Chain Stay Angle: 61-66 - Chain Line: 43.5 - Band Mount: 28.6 / 31.8 (w/AdapterS) 34.9

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

- Ergonomic Shifting Operation Without Stress - Shimano Synchronized Shift - Low Profile Rear Derailleur Design - Shimano Shadow Rd - Race Endurance For Less Damage In Crush - Maintains Compact And Smooth Appearance - Maximum Sprocket: 30T - Minimum Sprocket: 11T - Maximum Front Difference: 16T - Total Capacity: 35T

The Shimano Altus 3x9 speed front derailleur offers light action and improved clearance for wide tires and mud. - 50mm chainline - Chrome-plated cage - 9-Speed

It's an all-new derailleur that's specifically designed and optimized to be motor-driven instead of cable-actuated. AXS powered components enable customization and scale to an individual rider's liking via the AXS App. It features a shorter cage for 10mm more ground clearance, with more chain wrap on the cassette to sit slightly further forward, and further inboard from mechanical Eagle. The Eagle AXS derailleur is smart enough to protect itself thanks to its incredibly resilient Overload Clutch. In the event of an impact, the motor gearbox disengages, giving the derailleur freedom to move, and instantly returns back to its position for a seamless experience for the rider. The system is tested to IP69K water and dust proofing standard for creek crossings, mud splatterings and the resulting post-ride pressure washings. - Enduro focus and trail ready - Forged aluminum cage - Stainless hardware - Black/Polar colorways - Eagle technology - Overload Clutch protection - AXS enabled componentry software that makes it possible to both program and personalize new SRAM and RockShox components - System is completely water and dust proof to IP69K - Eagle AXS is designed to work with X-DOME Eagle cassettes only, providing the most precise, silent, and reliable shift performance available.

Shimano's Claris rear derailleur is a perfect replacement part or upgrade for 8-speed road drivetrains. HyperGlide technology results in smoother, faster shifting. - Maximum cog size: 32t (SS) / 34t (GS) - Total capacity: 37t (SS) / 43t (GS) - Pulleys: 11t - Chain compatibility: HG 8-speed

Eleven speeds to rule all the trails. That is the X1 Rear Derailleur's motto. It packs a massive amount of technology into its compact, lightweight aluminum body. This 11-speed gear changer uses a “horizontal parallelogram” design that limits all movement to the horizontal axis, reducing the force it takes to shift. The Type 2 clutch is brilliant. This self-lubricating, one-way roller clutch controls your chain tension to eliminate chain slap and give you smooth, consistent shifts over any terrain. For quicker, smoother, more exact shifting, the large upper pulley's offset design maintains a consistent chain gap across all gears.

Incredibly fast, astonishingly quiet and impressively precise—fly through all 11 gears with SRAM's Rival 22 Rear Derailleur. It takes advantage of SRAM's Exact Actuation technology for precision shifts every time. Carefully shaped jockey wheels work together with the sculpted chain pulley cage for lightning-fast, ultra-precise shifts, and an elastomer coating applied to the jockey wheels makes for extra quiet operation. Aluminum inner and outer cages, aluminum links, and stainless steel hardware keep the durable Rival 22 at a svelte 191 grams. Plus, SRAM's WiFLi technology delivers a wider range of gears than your standard triple, faster shifts through two chainrings and every gear on the rear cassette, all with significant weight savings.

With SRAM's RED Rear Derailleur, SRAM set out to make their already race-proven design lighter, faster, and quieter. Through careful analysis of design, material selection, and component integration, they achieved all three. Refined shaping and a hollow titanium fixing bolt lighten the overall weight while maximizing performance. Carefully sculpted jockey wheels work together with the new chain pulley cage for lightning-fast, ultra-precise shifts. An updated elastomer coating applied to the jockey wheels makes for extra quiet operation. Plus, a redesigned shift cable routing makes set-up and adjustment easier than ever! Light, fast, and quiet, the RED derailleur delivers!

- 10/11 Speed compatible - MTB: Direct attachment (Shadow+) - 11T Min top Sprocket - 46T(1x10), 42T(2x11/2x10) : Max Low Sprocket

The SRAM RED front derailleur, thanks to Yaw technology, changes everything, eliminating the need for shifter trim. Instead of simply moving back and forth, the derailleur cage actually rotates to maintain a consistent angular relationship with the chain. As a result, shifts feel more direct and precise. Combined with the SRAM RED crankset and X-GlideR chainrings, it delivers an unmatched performance advantage in front shifting. - SRAM Road 11-speed compatible - Yaw Technology - Slim spring design eliminates frame interference - Optimized for shifting with X-GlideR chainrings - Precision install markings - Integrated chain spotter protects your frame without adding any extra clunk and adjusts independently of the derailleur itself - Speeds: 2x11 - Material: Aluminum outer cage, Tool steel inner cage, Composite tail - Weight: 69g (braze-on), Chain spotter: 10.2 grams - Outer Cage: Aluminum - Compatibility: SRAM RED 22 & Force 22 Front Shift-Brake levers & X-GlideR Chainrings, SRAM R2C Aero SL-1190 shifters, SRAM R2C Aero SL-1150 shifters, SRAM 900 Aero brake levers, SRAM 500 Aero brake levers - Inner Cage: Tool steel

The SRAM NX X-HORIZON rear derailleur provides the same smooth, reliable shifting action as XX1—from the larger upper pulley offset to the 12-tooth X-SYNC pulley wheels. By eliminating unwanted chain movement, X-HORIZON shifts faster, puts an end to ghost shifting and reduces shift force and chain slap. And with Cage Lock technology, wheel removal and installation are easier than ever. - X-HORIZON design that reduces shift force, ghost shifting and chain slap - 12-tooth X-SYNC pulley wheels - Fully compatible with all SRAM MTB 1x drivetrains - Most affordable fully featured 1x rear derailleur in the industry - Speeds: 11-speed - Weight: 322 grams - Color: Black - Compatibility: X-ACTUATION - Bearings: Steel - Cage Size: Long - Max Tooth: 42

Centos front derailleurs are precisely manufactured for responsive, accurate shifting under race conditions. - Compatible with Shimano Tiagra 4700 10-speed road systems - Includes adapter for 31.8 and 28.6mm seat tubes