Derailleurs

Shimano's Tourney long cage rear derailleur incorporates advanced Shimano functions and styling that sets the standard for entry level components. - TY model comes with resin bracket and plate body for reduced weight - Zinc-plated adjustment screws for corrosion resistance - MegaRange compatible - Includes frame hanger - Maximum cog size: 34t - Total capacity: 43t

Shimano's Deore XT Rear Derailleur uses cold-forged construction and cutting edge technology to deliver crisp shifting, real-world reliability, and trademark precision. Plus-type derailleurs use a lever-actuated clutch spring to prevent chain slap, reduce noise while on the trail, and improve chain engagement when riding over rough terrain. Sealed pulley bearings keep things spinning smoothly, and wide plate construction prevents the derailleur from getting clogged with mud and debris.

- Compatible with 6 and 7-speed SIS Index Shifting drivetrains - Includes BMX/track frame hanger

Elevating the shift, expanding the capable, the X01 Eagle derailleur features an updated cage architecture to provide better chain management than ever. The X01 Eagle rear derailleur works with the new 10-52T cassettes and is backward-compatible with 10-50T options, as well. - Updated cage provides better chain retention and more precise shifts - Backward-compatible design works with 10-50T and 10-52T cassettes

The Shimano Tourney TX800 front derailleur offers precise shifting with HYPERDRIVE technology for 3x8 speed drivetrains. - Action: TOP SWING - Angled clamp band design - Applicable Top-Mid tooth difference: 10T - Chain line: 47.5/50mm - Chain stay angle: 66-69 - Top gear teeth: 42T/48T - Total capacity: 20T

Enjoy quality and reliability with the Shimano Tourney 6/7-speed rear derailleur. It makes use of Shimano SIS, HyperGlide, and Double Servo technologies for smooth, accurate shifts. - Maximum cog size: 34t - Total capacity: 43t

The Dura-Ace Front Derailleur is Shimano's top-of-the-line front changer. The body is made of cold-forged aluminum for lightness with top-notch strength, and the pivots are extra wide for amazing shifting. The lightweight, replaceable aluminum cage is nickel plated for durability. Plus, the 7900 is designed to eliminate the need to trim the derailleur to prevent chain rubbing.

SRAM's X4 Rear Derailleur provides precise, dependable shifting along with long-term durability. Its aluminum and steel construction delivers through the roughest trail, while SRAM's 1:1 actuation ratio and direct cable routing provide quick, reliable shifts. This derailleur is compatible with 7- or 8-speed drivetrains.

One rear derailleur to rule them all. The SRAM Force eTap AXS rear derailleur is designed for both 1x and 2x systems. It capitalizes on X-Range gearing technology for enhanced range and chain management and features larger pulleys for improved durability and efficiency. Strong, smooth, quiet and AXS enabled. - SRAM AXS enabled, allowing easy personalization - Orbit chain management technology keeps the drivetrain quiet and secure - A single rear derailleur for all gearing combinations, including 1x and 2x - Larger X-SYNC pulleys for increased durability and efficiency - NOTE: Does not include eTap battery. Compatible with existing eTap batteries.

The Box Four Rear Derailleur is the base of Prime 9 Technology that offers an affordable clutch based 1 by 8-speed derailleur that is simple and light; this makes it a perfect candidate for every entry-level bike that traditionally has a 3 by drive-train that is neither durable nor user friendly.

SRAM's low-profile GX 2x10 Front Derailleur was designed specifically around SRAM X-GLIDE shifting. This stiff, strong front derailleur provides, crisp, precise action for fast, smooth and reliable shifting season in and season out.

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.

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.

The Box Two Prime 9 Rear Derailleur is very similar to the Box One version however, to be more wallet friendly, it offers a non adjustable Tri-Pack Clutch, bushing pulleys and some muted finishes. Box Two rear derailleurs are still optimized for 11-50t cassettes and offer durability and performance for the most demanding terrain, just at lower price!

Occupying a new realm in shifting performance, the redesigned XX1 Eagle derailleur gives no-compromise racers and dream-bike builders a true top-tier option. The crisp, precise XX1 shifting feel athletes rely on now features an updated cage geometry for improved chain management. Occupying its rightful place at the top of the Eagle ecosystem, the XX1 Eagle rear derailleur makes full use of the new 10-52T cassettes and is backward-compatible with 10-50T cassettes, as well. - Updated cage geometry provides better chain retention and crisper shifting - Comes in XX1 Eagle master colorway as part of Eagle Colorsystem to go with all cassette and chain color options - Backward-compatible with 10-50T cassettes, works with new 10-52T cassettes

- SHADOW low profile design - Min cog size : 11T - Max cog size : 34T - Max front difference : 22T - Capacity : 45T

Claris R2000 series offers reliable functionality at a price point for new riders. Designed for easy rides around town with the durability to handle a long tour, Claris R2000 has a sporty design and promises the opportunity of comfortable and casual riding.

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 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

Riders want the derailleur to do its job shifting on command, whether under climbing load or the stage finish. The GX Eagle derailleur gets it done with an updated cage architecture that improves chain management. Refined to work with the new 10-52T cassettes, it's also backward-compatible with 10-50T cassettes for greater versatility and incremental upgrade. It's finished with the new GX Eagle master colorway to complement any cassette and chain colorway a rider wants from the Eagle Colorsystem. - Backward-compatible—works with both 10-50T and newer 10-52T cassettes - Updated cage architecture provides better chain retention and precise shifts

- 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

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

• 5/6/7-speed rear derailleur • Highly affordable and reliable • SHIMANO Equivalent RD-TY21 / RD-A070 • 301 grams

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

If your ride doesn't feel complete until you get a little dirt on your tires, you know the importance of capable components that can tackle anything. The RED XPLR eTap AXS rear derailleur is a dedicated 1x-specific unit designed for use with the XPLR 10-44 cassette. It makes for an uncluttered drivetrain that takes on pavement and singletrack with equal aplomb. Wireless and proven eTap shift logic, AXS connectivity and advanced chain management mean this derailleur does exactly what you want when you need it. - Wireless electronic eTap shift logic for intuitive shifting, easy setup, and reliability - 1x specific for use with 10-44T XPLR and 10-36T cassettes - SRAM AXS enabled, allowing easy personalization - Chain management keeps the drivetrain quiet and secure - Large X-SYNC pulleys for increased durability and efficiency - Compatible with existing eTap batteries - Cage Material (RD): Aluminum - Pulley Bearings Material: Ceramic - Max Tooth: 44 NOTE: Does not include eTap battery. Compatible with existing eTap batteries.

With SRAM's WiFLi RED Rear Derailleur, SRAM set out to make their already race-proven design faster, quieter, and able to accommodate a full 11-32 cassette for a huge gear range. 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! Fast, quiet, and capable, the RED derailleur delivers!

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.

R8 front derailleurs feature a cold forged aluminum body and are optimized for 7 and 8-speed chains and Shimano-compatible road shifters.

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

- 6061 Forged Alloy - Made to O.E.M. specifications - Correct hardness to reduce damage to frame upon impact

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

Run silent, run deep. Shimano's ZEE rear derailleur uses a short cage and a Shadow profile to keep tucked out of the way of rocks, roots, whatever. The Plus part is a one-way clutch system that stabilizes the cage and your chain when ripping over rough terrain. Chain slap and the noise that goes with it, as well as dropped chains, are virtually eliminated. Of course, it still has the smooth action and sniper-like shifting that Shimano is rightly famous for. Freeriders and trail riders can run a typical MTB cassette like an 11-32, 11-34, or 11-36. And DHers can choose the close-ratio version and run a road cassette like 11-23, 11-25 or 11-28.

Designed with the attention to detail and performance levels demanded of Campagnolo by World Tour cyclists, the Centaur is accurate and fast – perfect for long rides. Inheriting top-of-the-range technologies from Revolution 11+ groupsets, the Centaur offers similar performance to professional components. The longer front connecting rod and the carefully designed one-piece steel cage ensure precise and reliable shifting, with minimal effort required to move from the little ring to the big ring. - Long lever arm creates additional torque for improved shifting - One piece steel cage shaped identically to Super Record for similar performance - Shaped outer semi-cage to improve downshifting speed - New rod design allows for higher shifting forces with less rider effort - Drivetrain Speeds: 11 - Double or Triple: Double - Derailleur Capacity: 16 - Front Derailleur Cable Pull: Bottom Pull - Front Derailleur Clamp: Braze-on - Max Ring (teeth): 55 - Weight: 103 grams - Front Der/Shifter Compatibility: Campy Centaur/Potenza/Chorus/Record/Super Record 2015+

- Cover up those unfinished and unused FD mounts with MRP cover plates - Offered in Decapitator version with built-in bottle opener - Alloy with matching alloy fastener, 12g - Made in Grand Junction, CO USA

With a race-worthy weight and the right gearing for any situation, microSHIFT's top-of-the-line ADVENT X rear derailleur delivers high-end performance without high-end headaches. By using a 10-speed chain and wide range 11-48T cassette with predictable, evenly spaced gear steps, ADVENT X allows you to find the right gear even in challenging conditions. Add in microSHIFT's proprietary ratchet-and-pawl clutch, larger pulleys with taller teeth for better chain retention, and metric adjustment hardware, and you've got everything you want and nothing you don't. - Compatible with ADVENT X 10-speed drivetrains only - Compatible with standard 10-speed chains - Ratchet-and-pawl clutch provides chain security and can be turned on and off with a switch - Metric adjustment hardware - Larger pulley and taller teeth for better chain security and higher ride height

Affordable and lightweight Shimano-compatible rear derailleur. Compatible with cassettes up to 36T. Features: - 8/7/6-speed - Short Cage max. front difference: 12T - Shimano-Compatible - Responsive and reliable parallelogram push-rod design - Composite outer link - Composite pulleys - Weight: 240g (Short) / 269g (Long)

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 Ultegra R8000 Shadow rear derailleur. - Sleek integrated appearance - Low-profile design - Race endurance - Optimized slant angle - Wide compatibility - Short cage covers: 11-25T to 11-30T - Medium cage covers: 11-28T to 11-34T - Model Number: RD-R8000 - Series: Ultegra - Maximum Sprocket: 30T - Minimum Sprocket: 11T - Maximum Front Difference: 16T - Average Weight: 200 grams (short cage type), 210 grams (medium cage type)

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

SRAM's X01 Rear Derailleur packs a massive amount of technology into its compact, lightweight 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.

M-series rear derailleurs are designed to work with 7, 8, and 9-speed Shimano-compatible mountain and road shifters. These legendary M26 rear derailleurs put cyclists of all ages back on their saddles with as little frustration as possible. - Robust composite and steel construction - Compatible with Shimano 7, 8, and 9-speed mountain and road systems

The Shimano Deore XT FD-M8100 front derailleur offers powerful and stable front shifting for 2 x 12 systems. - Increased traction range and no chain rub for long travel bikes - Extra wide range with front double 36-26T - Compatible with 2.3-inch tire on wider rims - Drivetrain Speeds: 12 - Front Der/Shifter Compatibility: Shimano Mountain - Front Derailleur Cable Pull: Front Pull - Front Derailleur Clamp: 34.9 (1-3/8") , 31.8 (1-1/4") , 28.6 (1-1/8") - Front Derailleur Style: Side Swing - Max Ring (teeth): 38

Shimano Deore XT RD-M8050 Di2 Rear Derailleur - Accurate and stable shifting in any condition - Instant response - Customized shift speed within Multi-shift - Powerful shifting - Seamless gear change even under high load - Smart and efficient gear selection with Shimano Synchro Shift - Single lever operation - Rider-programmable shift mapping - Drivetrain Speeds: 11 - Maximum Sprocket: 42T(2x11-speed)/46T(1x11-speed) - Minimum Sprocket: 11T - Front Difference: 10T - Total Capacity: 35T - Average Weight: 320 grams

- Ergonomic Shifting Operation Without Stress - Shimano Synchronized Shift - Race Endurance For Less Damage In Crush - Quick And Smooth Front Shifting "Under" High Pedaling Torque - Maintains Compact And Smooth Appearance - Top Gear Teeth: 46-55T - Chain Stay Angle: 61-66° - Chain Line: 43.5mm

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

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

Compatible with DUAL SIS index shifting, the Shimano Tourney TY front derailleur is perfect for 3x7 and 3x6 speed drivetrains. - Action: TOP SWING - Angled clamp band design - Applicable Top-Mid tooth difference: 10T - Chain line: 47.5/50mm - Chain stay angle: 66-69 - Top gear teeth: 48T - Total capacity: 20T

- Alloy cage with adjustable chain stabilizer - Forged alloy links - 14t lower pulley and 12t upper pulley - Max rear sprocket is 50t with 1X setup; 42t with 2X - 10/11/12 speed compatible (Shimano 10/11 speed & SRAM 12 speed)

- Adjustable chain stabilizer - Alloy cage and links - Max rear sprocket is 50t with 1X setup & 46t with 2X - 9 speed compatible

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

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

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.

FD-A073 Tourney Front Derailleur for 2x7 or 3x7 drivetrains. - SG-X chainring compatible - Quick assembly - Interchangeable with SHIMANO road 7-speed system - Easy adjusting - Light operation and smooth shifting

SRAM's Ceramic Bearing Rear Derailleur Pulleys run on super-smooth and efficient ceramic bearings so your drivetrain pedals with ease. They are also lighter than conventional pulleys. These fine pulleys even come with SRAM's ceramic-bearing grease in an easy-to-use 10ml syringe container.

SRAM's GX 1x11 X-Horizon rear derailleur is engineered for smooth, reliable shifting action—from the larger upper pulley offset to the 12-tooth X-Sync pulley wheels. By eliminating unwanted chain movement, this X-Horizon rear derailleur 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. • Long cage • X-Horizon design reduces shift force, ghost shifting, and chain slap • 12-tooth X-Sync pulley wheels • Large upper pulley offset automatically adjusts chain gap • Sealed cartridge bearings • Aluminum Cage

Designed with the rider in mind, the ADVENT rear derailleur packs trail-ready features into an attainable wide-range drivetrain system. The derailleur kinematics are precisely tuned to use a more direct cable path, making the shifting feel consistent across the lowest and highest gears, and everything in between. - Clutch provides stronger chain management over rough terrain - Ratchet-and-pawl clutch is easily adjustable and repairable - Direct cable routing for smooth, responsive shifting - Compatible with 11-42T 9-speed cassettes - Compatible with ADVENT shifters only

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