The bicycle derailleur is a component that often goes overlooked by cyclists and is often not given the attention it deserves. However, a bike’s derailleur is one of the most important components on the bike, affecting the bike’s performance in a major way. While it may not be the most exciting component to talk about, it’s something you should definitely put some serious thought into before buying a bike.
In this guide, we’ll cover all the important things to know when shopping for a rear bike derailleur.
Read on to learn more.
Our Editor’s Best Rear Bike Derailleurs Reviews
- [IMPORTANT] It's Direct Mount Rear Derailleur for Mountain Bike, not Hanger mount
- Shimano TX35 6 / 7-speed rear derailleur (bracket attachment)
- SIS rear index shifting
- SGS cage can handle wide range gearing and 34 tooth sprockets
- 13 tooth pulleys offer long service life and less noise
- 【Model】RD-TY300-SGS; Bike 6/7 Speed Rear Derailleur for most kinds of bikes like mountain bike, hybrid bike, kids bike, cruiser bike etc.
- 【Features】Smooth shifting, 6/7 speed derailleur is easy and fast to install. Bracket fit (under wheel nut) Long cage tourney derailleur, total capacity 43T, pulley/Teeth 13/13T. Low sprocket: Max. 34T; Low sprocket: Min. 28T; Top sprocket: Max. 14T; Top sprocket: Min. 11T.
- 【Type】Long cage tourney derailleur, RD-TY300-SGS 6/7 speed derailleur is compatible with 11T /14T high speed gear.
- 【 Stability】Made of high quality durable aluminum alloy material and come with excellent shifting performance ensure your safe and stable while riding.
- 【Application】RD-TY300-SGS is compatible with 6 and 7-speed SIS INDEX variable speed transmission systems. Suitable for MTB, mountain bikes, road bikes, folding bicycles, commuter bikes, tricycles, eletric bikes etc.
- Material: aluminum
- Capacity: 41t
- Cassette Range: [2 x 11/10] 42t, [1 x 10] 46t
- Gearing: [long] 2 x 11, 2 x 10, 1 x 10
- Compatibility: HG-X11 11-speed, HG-X 10-speed
- TX models come with Smart Cage which gives MegaRange compatibility with a shorter derailleur cage
- Largest Cog: 34
- Chain Wrap Capacity: 43
- Cage Length: Long
- Drivetrain Speeds: 8
- MODEL: RD-TY21B bike rear derailleur, Compatible with 6 and 7-speed SIS Index Shifting drivetrains.
- IMPORTANT: The bike rear derailleur is hanger mount (hub bolt mount), not direct mount.
- EXCELLENT PERFORMANCE: Accurate gears provide light and stable shift performance, and making riding easy and comfortable.
- MATERIAL: Made of high-quality steel materials, durable and long service life. Easy to install and disassemble.
- APPLICATION: Suitable for MTB mountain bike, road bikes, variable speed bicycle, folding and city bikes. It is your indispensable bicycle accessories during your cycling journey.
- MODEL: RD-TZ31-A bike rear derailleur, Compatible with GS 6 / 7 speed SIS Index Shifting drivetrains.
- STABILITY: Durable aluminum alloy and plastic alloy material, Providing excellent shifting performance ensure safe and stable.
- PARM: Total capacity 34T, Largest sprocket 28T, Smallest sprocket 14T, Front chain wheel tooth difference 20T.
- NOTE: The bike rear derailleur is direct mount, not hub bolt mount. Please check the mount type of the original part before ordering, if bike frame with hook, as picture shows, you can use it.
- COMPATIBILITY: Suitable for mountain bikes, road bikes, folding bicycles and so on.
- 【Model】RD-TY300-SGS；Bicycle rear derailleur 6/7 speed Direct Mount , please check your suitable bicycle parts carefully before purchase
- 【Features】 Smooth shifting, easy and fast to install. Bracket fit (under wheel nut) Long cage tourney derailleur, total capacity 43T, pulley/Teeth 13/13T. Low sprocket: Max. 34T; Low sprocket: Min. 28T; Top sprocket: Max. 14T; Top sprocket: Min. 11T
- 【Type】Long cage tourney derailleur, compatible with 11T /14T high speed gear
- 【Built to Last】 High-Quality Aluminum Alloy Construction with Hollow Weight-Reduction Design. Nylon wear-resistant aluminum alloy guide wheel for silent, smooth, and non-wearing chain
- 【Easy Installation and Maintenance】 Direct Mounting Design for Fast and Convenient Setup.It can be adjusted slightly in multiple places to ensure accurate speed change performance
- MODEL: RD-TY21B; Bike rear derailleur is compatible with 6/7 speed most kinds of bikes.
- PERFORMANCE: Durable aluminum alloy material and excellent shifting performance ensure safe and stable riding.
- WIDE APPLICATION: This bicycle transmission is Suitable for MTB, mountain bikes, commuter bike, cruiser bike, folding bike etc.
- NOTE: The bike rear derailleur is hanger mount, not direct mount .Please check the mount type of the original part before purchasing. If you have any questions, please feel free to contact us, we will provide you with professional services.
- 【Engineered for Multi-Speed Bikes】 The RD-M310 7/8 speed bike rear derailleur, featuring high-performance RD-CT95 Altus technology, compatible with 7/8 speeds, delivers a smooth riding experience, perfect for your biking adventures. Offers superior performance and reliability, suitable for everyday and light mountain biking
- 【Lightweight Design】 Designed to be lightweight, reducing bike weight, enhancing speed and maneuverability, ideal for leisure cyclists and urban riders who demand reliable performance. Suitable for those with certain performance requirements for their bikes
- 【Strong Adaptability】RD-M310 7/8 speed derailleur with a maximum rear sprocket of 34T and total capacity of 43T, it adapts to various riding needs, ensuring easy handling on different terrains
- 【Versatile Application】 Fits various bike types including mountain, road, racing, city, and folding bikes, adding versatility to your cycling experience
- 【Easy Installation】 Direct installation onto the bike's rear, avoiding the hassle of rack mounting. Make sure to choose the correct installation method before purchase 7/8 speed derailleur
Best Rear Bike Derailleurs Buying Guide
Before choosing the best rear bike derailleurs you should consider following options:
1. Rear Derailleur Capacity: You’ll want to make sure you choose a derailleur that has enough capacity to support the chainrings and cassette you intend to use.
The numerical value on a derailleur is expressed as a number. The first number is the percentage of the total chainring capacity the derailleur is designed to support.
So, a derailleur with a capacity of 28 is designed to support 28% of the chainring capacity.
A derailleur with a capacity of 28 will support chainrings up to 32-tooth in the smallest chainring and 17-tooth in the largest chainring.
You’ll also see a second number on some derailleurs expressed as a ratio. So, a derailleur with a capacity of 28-tooth is sometimes expressed as 1:2.
What this means is the derailleur is designed to support 28% of the chainring capacity with a 14/28 combo.
The second number represents the chainring capacity the derailleur is intended to support divided by the total chainring capacity. So, in this example, the derailleur is designed to support 28% of the chainring capacity with a 14/28 combo.
2. Rear Derailleur Capacity: You’ll want to make sure you choose a derailleur that has enough capacity to support the chainrings and cassette you intend to use.
The numerical value on a derailleur is expressed as a number. The first number is the percentage of the total chainring capacity the derailleur is designed to support.
So, a derailleur with a capacity of 28 is designed to support 28% of the chainring capacity.
A derailleur with a capacity of 28 will support chainrings up to 32-tooth in the smallest chainring and 17-tooth in the largest chainring.
You’ll also see a second number on some derailleurs expressed as a ratio. So, a derailleur with a capacity of 28-tooth is sometimes expressed as 1:2.
What this means is the derailleur is designed to support 28% of the chainring capacity with a 14/28 combo.
The second number represents the chainring capacity the derailleur is intended to support divided by the total chainring capacity. So, in this example, the derailleur is designed to support 28% of the chainring capacity with a 14/28 combo.
3. Body Material: Most derailleurs are made from aluminum or steel, but there are some made from carbon.
The advantage of a derailleur made from carbon is that it weighs less than steel or aluminum. The disadvantage is that they are more expensive.
4. Cage Material: Most derailleurs are designed with either a steel or titanium cage. The advantage of a steel cage is that they offer a more durable and rigid feel. The disadvantage is that they weigh more than titanium cages.
The advantage of a titanium cage is that they are lighter. The disadvantage is that they don’t feel as rigid.
What else you should know about rear bike derailleurs
1. What are the best rear bike derailleurs?
Some of the best rear bike derailleurs are made by Shimano, SRAM, and Campagnolo. These companies make derailleurs that are designed to work with their own respective drivetrains, so it is important to make sure that the derailleur you choose is compatible with the components on your bike. Shimano and SRAM derailleurs are generally considered to be the best performing, while Campagnolo derailleurs are known for their durability and ease of maintenance.
2. How do I choose a rear bike derailleur?
The size of your rear derailleur will be dictated by the number of cogs (speeds) on your rear cassette. You will need a derailleur that is compatible with the number of cogs on your rear cassette. Additionally, you will need to make sure that the derailleur is compatible with the number of gears (speeds) on your shifters.
3. What are the features of a good rear bike derailleur?
The features of a good rear bike derailleur are that it is lightweight, has low friction, and is durable.
4. How do I install a rear bike derailleur?
1. Unscrew and remove the rear wheel of your bike.
2. Unscrew the derailleur hanger from the frame of the bike.
3. Place the new derailleur hanger onto the frame and screw it in tightly.
4. Attach the derailleur to the hanger.
5. Screw the rear wheel back onto the bike.
5. How do I adjust a rear bike derailleur?
To adjust a rear bike derailleur, you will need to turn the adjusting barrel clockwise to tighten the cable, or counterclockwise to loosen the cable.
Conclusion
On the market, there are numerous best rear bike derailleurs. Hopefully, the list of the top ten best rear bike derailleurs will save you time researching and deciding on the best one for you.