The Shimano Altus RD-M310 rear derailleur is a quality, durable replacement rear derailleur for 7 and 8-speed drivetrains. - 13t upper and 15t lower pulleys - Maximum cog size: 34t - Total capacity: 43t

Eagle range on a drop bar bike? Now that's a party. The Apex Eagle rear derailleur quietly and quickly shifts across our 12-speed Eagle cassettes, while 1x-specific chain retention technology keeps the chain where it needs to be. It's the best of our road and mountain bike innovations in one package. - Compatible with 50T and 52T Eagle cassettes - Works with 12-speed mechanical Apex and Eagle shifters - Use with Eagle chain - Roller Bearing Clutch controls chain tension for consistent shifting - X-HORIZON straight parallelogram design limits all movement to the horizontal axis, which makes ghost shifting impossible while also reducing shift force - Cage Lock technology makes for fast wheel changes or chain installation

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

The new TR12 rear derailleur is able to provide a quiet and accurate ride over the roughest trails. The key feature to this pursuit is the Hall Lock. During the Race season, lead mechanic for Intense Factory Racing, John Hall, noticed excessive movement around the B-knuckle when riding over rough rock gardens and in tracked out corners. This was leading to more chain skipping and slapping creating possible variances in shifting. This inspired John's idea to lock the B-knuckle to the bike's derailleur hanger. TRP engineers worked closely with Hall to create this feature, The Hall Lock. - Hall Lock - G-Spec Ratchet Clutch - G-Spec finishing touches - Carbon fiber cage & upper link - Extra-wide parallelogram pivot - Sealed cartridge bearing pulleys

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

SRAM's Force WiFli Rear derailleur is made for wide-range 2x10 systems. Its long cage can handle an 11-32 cassette! You get the huge gear range of a triple with reduced weight and better shifting. Of course, the WiFli still uses SRAM's renowned Exact Actuation technology for precision shifts every time. Plus, the Force is crafted with cutting-edge materials, such as a super-light carbon cage and a magnesium inner link for feathery low weight, flawless shifting and reliability.

SRAM's X5 9-Speed Rear Derailleur provides precise, dependable shifting along with long-term durability. Its aluminum construction keeps the weight down, while SRAM's 1:1 actuation ratio and direct cable routing provide quick, reliable shifts.

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.

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!

Incredibly fast, astonishingly quiet and impressively precise — fly through all 11 gears with SRAM's Force 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. A carbon outer cage, aluminum inner cage, and magnesium inner link keep the Force 22 at a svelte 178 grams.

Incredibly fast, astonishingly quiet, and impressively precise — fly through all 11 gears with SRAM's Force 22 WiFLi 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 cage for lightning-fast, ultra-precise shifts, and an elastomer coating applied to the jockey wheels makes for extra quiet operation. A carbon outer cage, aluminum inner cage, and magnesium inner link keep the Force 22 WiFLi at a svelte 190 grams. The WiFli version shifts up to a 32T max cog for a super-wide gear range.

On any surface you can imagine, in any drivetrain configuration, the Rival eTap AXS rear derailleur will handle it. Secure chain management and fast, precise shifting make for a smooth and quiet ride, every time. - Wireless electronic eTap shift logic for intuitive shifting, easy setup, and reliability - Compatible with both 1x and 2x drivetrains - 36T cog max derailleur works with 10-28T, 10-30T, 10-33T, and 10-36T cassettes - SRAM AXS-enabled, allowing easy personalization - Spring clutch keeps the drivetrain quiet and secure - X-SYNC pulleys for increased durability and efficiency - 36T max rear cog - Battery Not Included

The heart of this microSHIFT Acolyte derailleur is the innovative SpringLock system. By pairing a customized linear rate high tension spring and a dual stage activation mechanism, we’ve developed a system that can provide substantial chain security when you need it and can be turned off when you don’t.  To engage the clutch, turn the engagement bolt clockwise until it clicks. There’s no way to overtighten the bolt. To disengage the clutch for wheel removal, flip the switch. It’s that simple. - Innovative SpringLock chain retention keeps chain in place over rough terrain - Direct path cable routing for smooth and responsive shifting - Compatible with 12-42T and 12-46T 8-speed cassettes - Compatible with Acolyte shifters only

Find new ways to enjoy trekking and daily flat-handlebar riding with this reliable rear Shimano CUES RD-U6020 Shadow derailleur's seamless shifting and pedaling. Its low-profile design and chain stabilization give riders the confidence to choose rougher routes. Plus, e-bikers will benefit from reliable, long-lasting performance thanks to its eBike rated design. - Stable drivetrain performance on trails, gravel, and city streets - Shadow low-profile design protects rear derailleur from obstacles in a wide variety of riding scenes - Designed and tested to provide enduring e-biking performance - 11t upper and 13t lower pulley wheels - Compatible with LINKGLIDE AND HG 11-speed chains

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.

Shimano's Tiagra Rear Derailleur GS (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-GS - Series: Tiagra - Cassette Compatibility: 10 - Maximum Sprocket: low sprocket: 34T / top sprocket: 12T (front double) / 20T low sprocket: 32T / top sprocket: 12T (front triple) - Minimum Sprocket: low sprocket: 28T / top sprocket: 11T (front double) / 20T low sprocket: 25T / top sprocket: 11T (front triple) - Maximum Front Difference: 16T (front double) / 20T (front triple) - Total Capacity: 39T (front double) / 41T (front triple)

This new NX Eagle derailleur features the proven SRAM 1x-specific X-HORIZON design. The larger, 14-tooth X-SYNC lower pulley easily facilitates 11- to 50- and 10- to 50-tooth cassette capacity, and also adds to NX Eagle's overall smooth-pedaling feel. The Type-3 ROLLER BEARING CLUTCH provides quiet, consistent performance and durability. - Eagle technology provides an expanded, optimum, gear range making you fast on the flats, giving you control on the climbs and unleashing your speed on the descents - Eagle is a complete drivetrain system that was developed to be an integrated high-performance ecosystem. The engineering and testing that went into the development provide for maximum performance, safety, and long-term durability to ensure a great consumer ride experience. We guarantee this performance when Eagle drivetrains are used as a complete ecosystem. For additional information, please contact your SRAM Sales Contact. - Completely new rear derailleur incorporating our proven X-HORIZON design and new Type-3 ROLLER BEARING CLUTCH technology - Eagle ecosystem-engineered mounting system and CAGE LOCK positioning add robustness - Eagle pulley technology provides greater efficiency, crisper shifting and quieter operation - Speed (RD): 12s - Cable pull ratio: X-actuation - Cage (RD): Long - Max tooth: 50 - Color (RD): Black - Pulley bearings material: Steel - Cage material (RD): Steel

Shimano Tourney TX is a basic 8-speed rear derailleur for entry-level sport bikes and riders. Enjoy durable, trouble free, and stable performance. - Maximum cog size: 34t - Total capacity: 43t

- 9-speed SHIMANO SHADOW RD rear derailleur - Low-profile design - Total capacity: 45T - Max. low sprocket: 36T - Adjustment barrel

The TR12 drivetrain system is the result of an intimate development relationship with 5x DH World Cup Overall Champion, Aaron Gwin, and his personal mechanic, John Hall. From start to finish, the project spanned more than two full years of conceptualizing to achieve this high-performance design. DERAILLEUR The new TR12 rear derailleur is able to provide a quiet and accurate ride over the roughest trails. The key feature to this pursuit is the Hall Lock. During the Race season, lead mechanic for Intense Factory Racing, John Hall, noticed excessive movement around the B-knuckle when riding over rough rock gardens and in tracked out corners. This was leading to more chain skipping and slapping creating possible variances in shifting. This inspired John's idea to lock the B-knuckle to the bike's derailleur hanger. TRP engineers worked closely with Hall to create this feature, The Hall Lock. - Hall Lock - G-Spec Ratchet Clutch - G-Spec finishing touches - Carbon fiber cage & upper link - Extra-wide parallelogram pivot - Sealed cartridge bearing pulleys SHIFTER Ergonomics are key to Aaron, which is why he wanted something a little different. As a result, TRP engineers looked at the cable release lever's ergonomics and devised a system to move it in a linear path to mimic the motion of a rider's thumb, rather than rotating it away. This unique positioning allows for a more consistent contact patch providing overall better grip and shifting performance when the trail gets rowdy. - Shift levers designed and located for optimum performance by Aaron Gwin - New linear actuation for improved ergonomics and consistent thumb contact - Enhanced grip & tactile feel built into lever paddles: embossed grooves on advance and release lever - Carbon fiber upper housing & advance lever position with brake lever - Ball bearing equipped - 12 speed - Tool-free straight-lace cable changes - Rider-adjustable home position of lower lever with a 40-degree range

The Campagnolo Chorus 12-speed rear derailleur features 3D Embrace technology and 12-tooth pulley wheels making it suitable for all cassettes as the distance stays optimum on each individual sprocket, regardless of the cassette selected. - Embrace technology not only keeps the rear derailleur vertically aligned in the perfect position for each sprocket, it now makes the upper pulley wheel advance perfectly in the direction the bike is advancing - On rough roads, the spring positioned between the upper body and the pivot absorbs the vibrations, ensuring the chain always rests properly on the sprockets - The pulley wheels on the 12-tooth derailleur cage allow the chain to move more smoothly - The initial position of the rear derailleur can be adjusted to suit any cassette. - The rear derailleur is positioned further back, making it easier to slide the wheel out and replace it - Upper and lower body crafted from technopolymer that is reinforced with long carbon fiber for exceptional durability 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 - Weight: 240g

SRAM's X5 10-Speed Rear Derailleur provides precise, dependable shifting along with long-term durability. Its aluminum construction keeps the weight down, while SRAM's 1:1 actuation ratio and direct cable routing provide quick, reliable shifts.

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 180 grams.

The SRAM Rival 1 rear derailleur is engineered for smooth, reliable shifting action, delivering 100% of what you demand. By eliminating unwanted chain movement, X-HORIZON shifts faster, reducing shift effort and chain slap. - X-HORIZON design reduces shift force while eliminating ghost shifting and chain slap - Large upper pulley offset automatically adjusts chain gap - Sealed cartridge bearings and aluminum cage - Technologies: X-HORIZON, EXACT ACTUATION, X-SYNC, ROLLER BEARING CLUTCH, Cage Lock - Medium cage: 11-26 through 11-36 cassettes, 269g - Long cage: 10-42 cassette, 275 g

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)

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

- Stable Shifting Performance - Pulley Follow-Up In Certain Distance - Shimano Shadow Rd Construction - Low Profile Rear Derailleur Design - Race Endurance For Less Damage In Crush - Adapted For Race Specific Frame Design - Maximum Sprocket: 30T - Minimum Sprocket: 11T - Maximum Front Difference: 16T - Total Capacity: 35T

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

- Upper pulley has larger teeth for increased chain control

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.