Best Mountain Rear Bike Derailleurs in 2026

Material: forged aluminum, [spring] titanium

Capacity: 42t

Cassette Range: 12-52t

Chain Wrap Capacity: 43teeth, Derailleur Action: Top-Normal (Traditional)

Derailleur Color: black, Drivetrain Spacing: Shimano/SRAM 8, Largest Cog: 34teeth

Shifter/Rear Derailleur : Shimano, Speeds: 8sp, Weight: 326g

Shimano Acera Rear derailleur compatible with all Shimano 7 & 8 Speed shifters. Advanced light action design.

Direct frame fit. SIS Rear index shifting.

Megapulley oversize jockey wheel. Smartcage pulley plate.

Rear Derailleur (3x8-speed)

8-speed drive train

Durable light action shifting peformance for stress free riding. Double Servo-panta Mechanism

Shimano fd-m310 Altus 8-Speed front derailleur, conventional swing, 42-48t, 66-69 degree

Model: RD-TY300 rear derailleur, compatible with 6 and 7-speed SIS INDEX variable speed transmission systems compatible with 11T /14T high speed gear

Stability: Durable aluminum alloy material and excellent shifting performance ensure safe and stable riding Smooth shifting,

Wide application: Rear derailleur is easy to use and maintain.Suitable for MTB,mountain bikes, road bikes, folding bicycles and so on.

Anodised CNC machined bicycle jockey wheel with fully sealed bearing for center bolt derailleurs

Specification:SHIMANO & SRAM

Fits for almost all mountain bike of 11T

Details:Compatible with the Cannondale Trail 15-19, Adventure 17-19, Bad Boy 16-19, Catalyst 16-19, Contro 15-16, Cujo 17-19, Foray 17-19, Kids Cujo, Kids Trail, Kids Quick, Kids Street, Kinneto, Law Enforcement, Mavaro Neo, Quick 16-19, Quick CX 15-19, Quick Neo 18, Scarlet, Tango16-19, Tesoro Neo, TreadwellThis solid derailleur hanger is designed to keep the derailleur stabilized during the roughest riding conditionsComes with hanger and mounting hardware (2 screws)

MODEL:RD-TZ31-A bike rear derailleur.This is a mountain bike derailleur, which is basically suitable for mountain bike, and can adjust the speed of 6 / 7.

Easy to Install: Adopt ergonomic design, with simple design, easy to install and remove, convenient to use.

Premium Quality:Accurate gears provide light and stable shift performance,and making riding easy.

【Model】 Shimano Tourney (SIS) RD-TZ31-GS 6/7 speed，medium-cage , direct mount.No retail packaging. Items as shown

【Specifications】 Total capacity(aka chain capacity) 34T, Largest sprocket 28T , Smallest sprocket 14T, Front chainwheel tooth difference 20T.

【Compatibility】 Compatible with 6 and 7-speed SIS Index Shifting drivetrains, for mountain bike.

Precise chain movement changes gears smoothly

Direct Mount

Light shift effort

Shimano RD-M310 (RD-CT95) Altus Rear Derailleur 7/8 Speed / D-ATT Black

Model: RD-M310 Compatible with: 7/8 speeds Max Rear Sprocket: 34T Total Capacity:43T

Shimano Altus 7/8 Speed Black RD-M310 Mountain Bike Rear Derailleur-Direct Mount

UNIVERSAL:  The Universal Derailleur Hanger consolidates thousands of mountain bike derailleur standards

PROTECTION: UDH protects your derailleur against chain jams by pivoting back and out of the way, and slips slightly when encountering impacts

MODEL: SHIMANO TOURNEY RD-TY200 bike rear derailleur, Compatible with 6 and 7-speed SIS Index Shifting drivetrains.

IMPORTANT: The Shimano direct mount rear derailleur for mountain bike, not hub bolt mount (hanger mount).

EXCELLENT PERFORMANCE: Accurate gears provide light and stable shift performance, and making riding easy and comfortable.

TX models come with Smart Cage which gives MegaRange compatibility with a shorter derailleur cage

TX models come with Smart Cage which gives MegaRange compatibility with a shorter derailleur cage

Chain Wrap Capacity: 43

MODEL:RD-TY300 Rear Derailleur,Suitable for 6/7/8 speed.

PERFORMANCE:Forged with high hardness aluminum alloy.The hollow weight-reduction design is adopted,and the speed change is more stable.

PRECISE ADJUSTMENT: High-hardness aluminum alloy body adjustment, adjustment is more precise. It can be adjusted slightly in multiple places to ensure accurate speed change performance.

EXACT ACTUATION for precise and dependable 10-speed performance

TYPE 2.1 technologies: ROLLER BEARING CLUTCH and CAGE LOCK (also available without TYPE 2.1 configurations)

Cage lengths: Short, Medium and Long

*Model：RD-TY21B rear derailleur compatible with 6/7 speed mountain bikes.

*Note:The bike rear derailleur is hub bolt mount (hanger mount),not direct mount .Please check the mount type of the original part before purchasing.

*Stability: Durable aluminum alloy material and excellent shifting performance ensure safe and stable riding.

Model: RD-TZ31-A; Bike rear derailleur, compatible with 6/7 speed mountain bikes, commuter bike, tricycle, folding bike etc.

Note: The bike rear derailleur is direct mount, not hub bolt mount. Please choose right mount way before you purchase.

Stability: Made of high quality durable aluminum alloy material and come with excellent shifting performance ensure your safe and stable while riding.

【MODEL】Bicycle rear derailleur RD-TY21B, suitable for 6-speed and 7-speed SIS index variable speed drives. Please pay attention to the speed when buying.

【Hook mounted】Before purchasing, please confirm whether the rear derailleur of your bicycle is directly installed or hook mounted. This model is a Hook mounted method.

【High-quality material】This bicycle rear derailleur is made of high-quality steel, sturdy and durable, not easily deformed and not easily damaged.

【PACKAGE】2 x Bicycle Derailleur Hanger Replacement.

【FUNCTION】Play to protect the transmission after dialing role.

【APPLICATION】Universal type fit for most of bike in case of emergency.

Shimano RD-TZ31 6/7 Speed Rear Derailleur Direct Mount For Mountain Bike

This is Direct Mount type, NOT hub bolt mount type，Material: High quality plastic and alloy

For 6/7 grade freewheel, SIS index shift, fit for mountain bike/road bike

Application:Provide effective protection for rear derailleur, prevent the derailleur was struck distortion or displacement in riding.

Size:115 X 54 X40 mm/4.5'' X 2.1'' X 1.57''

Easy to installed:Just be fixed in the corresponding hole position;

Universal Derailleur Guard for Quick Release or Bolt on Rear Axles.

Easy to installed:Just be fixed in the corresponding hole position.

Made of strong steel,very durable,suitable for most mountain bikes, road bikes, folding bicycles, racing bikes.

Material: POM Teeth, NSK steel bearing, sice cap is alloy 7075-t6,shim is alloy 6061-t6

Teeth : 10T 12T 14T 16T

Weight: 10g/12T ; 12g/14T; 15g/16T

Rear derailleur: 7/8/9 speed, direct mount

Stability: Durable aluminum alloy material and excellent shifting performance ensure safe and stable riding.

Note:The bike rear derailleur is direct mount,not hub bolt mount.

Model: RD-TY21B rear derailleur compatible with 6/7 speed mountain bikes.

Note:The rear derailleur is direct mount,not hub bolt mount .Please check the mount type of the original part before ordering.

Stability: Durable aluminum alloy material and excellent shifting performance ensure safe and stable riding.

【Rigorous Design】:Double (top or bottom) pull, 3-speed design, can matching 6/7/8/9/10/11 speed rear derailleur (★Don't matching 12 speed rear derailleur).

【Dimension】:Clip ring supports 31.8/34.9mm diameter tube. Crankset: 3 gears, compatible crankset 22-42T. universal for most mountain bike.

【Easy To Use】:Attach the front derailleur to the bike frame, temporarily tighten the toggle bolts, and then adjust the flat part of the chain guide outer guide plate to be parallel to the flat surface of the maximum crankset. Make adjustments, make it have 1-3mm space between the outer guide of the chain guide and the maximum crankset. After the adjustment is complete, tighten the ring bolts.

The Rear Derailleur Guard is certainly worth purchasing if your derailleur is unprotected. It Provides effective protection for rear derailleur, prevent the derailleur was struck distorti on or displacement in riding

The Rear Derailleur Guard is very easy to install and will actually protect the Derailleur in the event of a drop.It is Great for the kids bikes like mountain bike or MTB .Made of strong steel,very durable,suitable for most mountain bikes, road bikes, folding bicycles, racing bikes

The Rear Derailleur Guard is heavy-heavy and really protects the rear shifting mechanism.The guard appears to be made of a strong steel that will definitely reduce any potential damage in the event of accidents.this item is meant to fit onto the wheel axle, and not on the Derailleur nut.

[Bike Rear Derailleur Hanger]: Well protecting your bike from being damaged in case of falling down with this derailleur hanger, it will absorb the impact to reduce the damage

[Durable Aluminium Alloy]: Made of high quality aluminium alloy, the rear derailleur hanger has good texture, smooth surface, practical durable for longer use

[Easy to Install]: Comes with screws, the derailleur hanger is easy to install and remove; Before installing a derailleur hanger, the rear dropouts need to be check for alignment. If the rear dropouts are not aligned and the new derailleur hanger is installed, it will break or bend