Rear derailleur is something I’d never thought I’d say outloud. However, if you’ve been moutain biking for any length of time you’ve probably had to adjust the mountain bike derailleurs. What’s a derailleur you might ask! It’s a fancy sounding name for the thing that adjusts the it’s position to keep the tension on the chain as you change gears. If you’re bike cost under $1,000 you probably need to upgrade that mountian bike derailler. Just like our review of chain tensioners, you’ll find that there are a plethora of choices when you want to select the best mountain bike derailleur. You can purchase a decent bike frame from a local store and then upgrade the parts and have a pretty solid mountain bike.
Best Mountain Bike Derailleurs
What you will learn in this Article
SaleBestseller No. 1 
Shimano RDM310DL Altus GS 7/8-speed Rear Der Black,Long Cage
- 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
SaleBestseller No. 2 
Shimano Tourney TY300 6/7-Speed Rear Derailleur with Dropout Claw Hanger
- Includes frame hanger
- Largest Cog: 34
- Chain Wrap Capacity: 43
- Cage Length: Long
- keyword search: Replaces rd8162
SaleBestseller No. 3 
SHIMANO Tourney 7/8-Speed Mountain Bicycle Rear Derailleur - RD-TX800-L (Black)
- Tourney RD-TX800 Rear Derailleur
Bestseller No. 4 
MOHEGIA Bike Rear Derailleur RD-TY21B 6/7 Speed Direct Mount for Mountain Bicycle-Black
- 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.
- Wide application: Rear derailleur is easy to use and maintain.Suitable for MTB,mountain bikes, road bikes, folding bicycles and so on.
- Important: Please feel free to contact if you have any questions, we will provide quality service.
Bestseller No. 5 
Inkesky RD-TZ31-GS 6/7 Speed Rear Derailleur with Direct Mount, Medium Cage, for Mountain Bike
- 【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.
- 【Incompatibility】 1) Not compatible with hub bolt mount (bracket mount) frame 2)If the total capacity of your bike exceeds 34T, this RD-TZ31 is not compatible with your bike, please konw before buying. Please see below for a detailed description of how to calculate total capicity.
- 【Tools Required】 5mm allen wrench
Bestseller No. 6 
ENBO Tourney Bike Rear Derailleur RD-TY300 6/7 Speed Sis Index Direct Mount for Mountain Bicycle (Not Hanger Mount)
- Model: RD-TY300 rear derailleur, compatible with 6 and 7-speed SIS INDEX variable speed transmission systems, upgraded of RD-TX35.
- Long Cage: RD-TY300 is long cage tourney derailleur, features an oversized jockey wheel, the total package capacity 43T.
- Technologies: Double servo, SIS index system, HG(HyperGlide).
- Installation: This rear derailleur is eye-mounted (direct mount), not hanger mount. TY300 is only suitable for 6 / 7 speed mountain bike, and cannot be installed on 8 / 9 speed mountain bike, which will cause damage. Please check the mount type of the original part before ordering.
- Application: Suitable for MTB mountain bike, road bikes, variable speed bicycle, etc. If you have any questions, please feel free to contact us. We will provide timely response and quality service.
Bestseller No. 7 
MRCUFF Bicycle Gears Really Moves Bike Cycling Cyclists Derailleur Pair Cufflinks Presentation Gift Box & Polishing Cloth
- MRCUFF Bicycle Gears Really Moves Bike Cycling Derailleur Pair Cufflinks Presentation Gift Box & Polishing Cloth
- Arrives in hard-sided presentation box ready for gift giving, then can be used for storage or display box. Your french cuffs or tuxedo will never look better than with MRCUFF on your sleeve.
- Perfect for weddings, formal or business attire, awesome gifts for best man, groom, father, boss, boyfriend, husband or dad.
- We make your gift giving choice easy for Anniversaries, special occasions, business, Christmas, Weddings, Birthdays and more.
- Microfiber polishing cloth for cuff links gift included with each set. 30 day, no reason needed return policy.
Bestseller No. 8 
SRAM XX1 Eagle AXS 12-Speed Rear Derailleur Black, One Size
- Material: [cage] carbon fiber, [hardware] titanium, [bearings] steel
- Capacity: [max tooth] 52
- Cassette Range: 10 - 50t, 10 - 52t
- Gearing: single
- Compatibility: SRAM Eagle AXS shifters (controller), SRAM X-DOME Eagle cassettes
Bestseller No. 9 
MRCUFF Bicycle Gears Really Moves Bike Cycling Cyclists Derailleur Steampunk Pair Cufflinks Presentation Gift Box & Polishing Cloth
- MRCUFF Bicycle Gears Really Moves Bike Cycling Derailleur Triathlon Pair Cufflinks Presentation Gift Box & Polishing Cloth
- Arrives in hard-sided presentation box ready for gift giving, then can be used for storage, travel case or display box. Your french cuffs or tuxedo will never look better than with MRCUFF on your sleeve.
- Perfect for weddings, formal or business attire, awesome gifts for best man, groom, father, boss, boyfriend, husband or dad.
- We make your gift giving choice easy for Anniversaries, special occasions, business, Christmas, Weddings, Birthdays and more.
- Microfiber polishing cloth for cuff links gift included with each set. 30 day, no reason needed return policy. Perfect for your favorite computer geek, nerd and kid at heart.
Bestseller No. 10 
JFOYH MTB 12 Speed Derailleur Groupset for Shimano and Sram Golden & Professional, Rear Derailleur+Shift Lever+Bike Cassette/12S 52T+YBN Chain/12S(4 Kit)
- 🚲1 OF 4: Rear Derailleur 1x12s, Shadow RD with Slant Design
- 🚲2 OF 4: Shift Lever 1x12s, 1:1 Tech Make Precise and Quick Response
- 🚲3 OF 4: 12 Speed Golden Cassette, 11-13-15-17-19-21-24-28-32-34-40-46-52T
- 🚲4 OF 4: 12 Speed Golden Chain, 1/2"*11/128", shaft length 5.25MM, 128 Knots
- 🚲Fast Delivery: Your Item will arrive within 14 days.
Bestselling Mountain Bike Rear Derailleurs
SaleBestseller No. 1
Shimano RDM310DL Altus GS 7/8-speed Rear Der Black,Long Cage
- 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
SaleBestseller No. 2
Shimano Tourney TY300 6/7-Speed Rear Derailleur with Dropout Claw Hanger
- Includes frame hanger
- Largest Cog: 34
- Chain Wrap Capacity: 43
- Cage Length: Long
- keyword search: Replaces rd8162
SaleBestseller No. 3
SHIMANO Tourney 7/8-Speed Mountain Bicycle Rear Derailleur - RD-TX800-L (Black)
- Tourney RD-TX800 Rear Derailleur
Bestseller No. 4
MOHEGIA Bike Rear Derailleur RD-TY21B 6/7 Speed Direct Mount for Mountain Bicycle-Black
- 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.
- Wide application: Rear derailleur is easy to use and maintain.Suitable for MTB,mountain bikes, road bikes, folding bicycles and so on.
- Important: Please feel free to contact if you have any questions, we will provide quality service.
Bestseller No. 5
Inkesky RD-TZ31-GS 6/7 Speed Rear Derailleur with Direct Mount, Medium Cage, for Mountain Bike
- 【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.
- 【Incompatibility】 1) Not compatible with hub bolt mount (bracket mount) frame 2)If the total capacity of your bike exceeds 34T, this RD-TZ31 is not compatible with your bike, please konw before buying. Please see below for a detailed description of how to calculate total capicity.
- 【Tools Required】 5mm allen wrench
Bestseller No. 6
ENBO Tourney Bike Rear Derailleur RD-TY300 6/7 Speed Sis Index Direct Mount for Mountain Bicycle (Not Hanger Mount)
- Model: RD-TY300 rear derailleur, compatible with 6 and 7-speed SIS INDEX variable speed transmission systems, upgraded of RD-TX35.
- Long Cage: RD-TY300 is long cage tourney derailleur, features an oversized jockey wheel, the total package capacity 43T.
- Technologies: Double servo, SIS index system, HG(HyperGlide).
- Installation: This rear derailleur is eye-mounted (direct mount), not hanger mount. TY300 is only suitable for 6 / 7 speed mountain bike, and cannot be installed on 8 / 9 speed mountain bike, which will cause damage. Please check the mount type of the original part before ordering.
- Application: Suitable for MTB mountain bike, road bikes, variable speed bicycle, etc. If you have any questions, please feel free to contact us. We will provide timely response and quality service.
Bestseller No. 7
SRAM XX1 Eagle AXS 12-Speed Rear Derailleur Black, One Size
- Material: [cage] carbon fiber, [hardware] titanium, [bearings] steel
- Capacity: [max tooth] 52
- Cassette Range: 10 - 50t, 10 - 52t
- Gearing: single
- Compatibility: SRAM Eagle AXS shifters (controller), SRAM X-DOME Eagle cassettes
Bestseller No. 8
JFOYH MTB 12 Speed Derailleur Groupset for Shimano and Sram Golden & Professional, Rear Derailleur+Shift Lever+Bike Cassette/12S 52T+YBN Chain/12S(4 Kit)
- 🚲1 OF 4: Rear Derailleur 1x12s, Shadow RD with Slant Design
- 🚲2 OF 4: Shift Lever 1x12s, 1:1 Tech Make Precise and Quick Response
- 🚲3 OF 4: 12 Speed Golden Cassette, 11-13-15-17-19-21-24-28-32-34-40-46-52T
- 🚲4 OF 4: 12 Speed Golden Chain, 1/2"*11/128", shaft length 5.25MM, 128 Knots
- 🚲Fast Delivery: Your Item will arrive within 14 days.
Top Shimano Mountain Bike Derailleurs
SaleBestseller No. 1
Shimano RDM310DL Altus GS 7/8-speed Rear Der Black,Long Cage
- 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
SaleBestseller No. 2
Shimano Tourney TY300 6/7-Speed Rear Derailleur with Dropout Claw Hanger
- Includes frame hanger
- Largest Cog: 34
- Chain Wrap Capacity: 43
- Cage Length: Long
- keyword search: Replaces rd8162
SaleBestseller No. 3
SHIMANO Tourney 7/8-Speed Mountain Bicycle Rear Derailleur - RD-TX800-L (Black)
- Tourney RD-TX800 Rear Derailleur
Bestseller No. 4
JFOYH MTB 12 Speed Derailleur Groupset for Shimano and Sram Golden & Professional, Rear Derailleur+Shift Lever+Bike Cassette/12S 52T+YBN Chain/12S(4 Kit)
- 🚲1 OF 4: Rear Derailleur 1x12s, Shadow RD with Slant Design
- 🚲2 OF 4: Shift Lever 1x12s, 1:1 Tech Make Precise and Quick Response
- 🚲3 OF 4: 12 Speed Golden Cassette, 11-13-15-17-19-21-24-28-32-34-40-46-52T
- 🚲4 OF 4: 12 Speed Golden Chain, 1/2"*11/128", shaft length 5.25MM, 128 Knots
- 🚲Fast Delivery: Your Item will arrive within 14 days.
Bestseller No. 5 
Mountain Bike, Aluminum Alloy 27.5" Frame Mountain bikes for Men, Shimano 21 Speed Derailleurs, Suspension Front Fork and Dual-Disc Brake System, with Seat Cover and Pump for Adult/Youth/Men and Women
- LIGHTWEIGHT & DURABLE CONSTRUCTION WITH DURABLE CRANK: Your 27.5” mountain bike is made with a lightweight aluminium frame that’s durable and can tackle any terrain with a strong crank that keeps your chain taught minimising maintenance, you’ll love the easy riding your mens mountain bike brings so you can just enjoy the journey.
- FREEDOM TO GO WHEREVER: No where is out of reach for your mountain bike, whether on or off the tracks, for daily riding or as a downhill mountain bike, yours has been specially designed with many features including integrated brake and shift lines for comfort, flexibility, durability and speed so you don’t have to worry about any snags along the way.
- 21 SPEEDS, ADVANCED SHOCK ABSORBER, SHARP BRAKING: Your men’s mountain bike comes with 21 variable speeds you can flick through easily to keep you on the move, an advanced shock absorber with 10mm dampening and disc brakes with a strong braking force to keep you safe there’s no where you can’t go. Your mountain bike responds with lighting reflexes so you can stay safe while feeling in complete control.
- EASY TO ASSEMBLE AND GO: Delivered near-fully assembled, your shimano mountain bike is effortless to assemble, only needing to install the front wheel, pedals, seat and handlebars and stays fixed no matter what you throw at it. When you want to travel and explore those hidden spots with more freedom, your downhill mountain bike can easily be taken apart for compact storage and travel.
- OUR PROMISE: We know you’ll love your new downhill mountain bike. However, if you’re not so sure we’ll offer a prompt and courteous refund. For any questions about your men and women’s mountain bike, our customer care team is available 24/7.
How To Set Up A Mountain Bike Derailleur
