Best Mountain Bike Derailleurs – Review and Buying Guide

The quality and efficiency of the derailleur can make or break your riding experience. A derailleur is a critical part of the MTB drivetrain. Therefore you must be highly investigative while buying an aftermarket derailleur for your mountain bike.

You must invest in fully compatible, high-quality derailleurs for smooth and reliable performance. SHIMANO and SRAM have introduced a wide range of aftermarket front and rear mountain bike derailleurs.

How do I choose a derailleur for my mountain bike?

Before buying a derailleur for your mountain bike, you must consider the specifications of your MTB drivetrains. Depending upon the maximum amount of slack it can handle, its frame dimensions, and gears ratio, you should look for a fully compatible aftermarket derailleur in the market. Also, you should consider other factors like weight, durable build quality, and price-performance ratio.

Best Mountain Bike Derailleurs Overview

IMAGE	PRODUCT	DETAILS
Best Overall	Best Overall	Shimano Deore XT RD-M786 MTB Derailleur	Compatible with : 10-Speed Brand : Shimano Weight: 0.8 lbs.	Check On Amazon
Highly Recommended	Highly Recommended	SRAM NX Eagle 12-Speed Rear Derailleur	Brand : SRAM Compatible with : Only 12 speed Weight: 1.1 lbs.	Check On Amazon
Most Attractive	Most Attractive	SHIMANO Deore XT FD-M8000 MTB Derailleur	Brand : Shimano Compatible with : 33 speed Weight: 0.58 lbs.	Check On Amazon
Editors Choice	Editors Choice	SHIMANO Unisex’s FDM313X6 Derailleur	Brand : Shimano Compatible with : 8-speed drivetrain Weight: 2.65 lbs.	Check On Amazon
Best Seller	Best Seller	SRAM X4 Derailleur – Best Rear Derailleur for Mountain Bike	Brand : SRAM Compatible with : Upto 10-speed Weight: 0.84 lbs.	Check On Amazon

5 Best Mountain Bike Derailleurs Review

To help you choose the best mountain bike derailleur, we have reviewed the five best mountain bike derailleurs you can find today. After testing dozens of options available on the market, we have selected the five options that offer durability and the best price-performance ratio. Additionally, our list includes both front and rear derailleurs, and a buying guide, in the end, will help you make a well-calculated decision.

Additionally, it comes with a stabilizer switch that prevents chain slapping and bouncing on sprockets. You can expect a smooth and unparalleled performance on bumpy and muddy terrains with such impressive stability.

Since this rear derailleur is made with the needs of mountain bikers in mind, it offers an impressive chain wrap capacity of 43T. This chain wrap capacity provides a wide range of gear, making your uphill and rides smooth and stable.

Furthermore, this is a direct mount rear derailleur. The biggest advantage of direct mounting is that it forms a strong linkage with the frame to make the gear shifts more accurate and precise.

Also, the direct-mount derailleur leaves a considerable gap from the rear wheel, making the wheel change quickly and effortlessly. The SGS pulley cage is another standout feature making it a perfect choice for the riders who cross the chains often. The long cage design is ideal for the long drivetrain of mountain bikes and enhances the stability on more challenging tracks.

Concluding Shimano Deore RD-M786 Derailleur Review

Shimano Deore XT RD-MT86 with long cage pulley and advanced clutch mechanisms combines versatility, precision, stability, and accuracy. This rear derailleur is rated five stars on Amazon for its ease of installation, smooth performance, and long-term performance.

Also have a look at my review on mountain bike hydraulic disc brakes

NX Eagle features Horizon-X and X-sync technology that promises precise and smooth gear shifting. X-sync tooth profile perfectly synchronizes with the alternating links in the bike chains for ultimate reliability and stability. Effortless gear shifting is another primary concern if you love to explore challenging tracks.

Thankfully this rear derailleur comes equipped with Type-3 roller bearings and an X-actuation clutch.  This advanced clutch and roller bearings system offers enhanced chain maintenance and reduces the impact to prevent chain slapping and bouncing over sprockets. The cassette range of this mountain bike derailleur is 11T-50T which is okay considering its competitive price.

Additionally, it is made with premium quality stainless steel for durable and long-term performance. However, steel adds a lot of weight to the derailleur making it heavier than its carbon and aluminum counterparts. Moreover, this derailleur comes equipped with a steel cage lock and cage lock button to prevent chain slapping and accidental chain bending when you are on more demanding terrains.

Concluding SRAM NX Eagle MTB Derailleur Review

SRAM NX Eagle 12-Speed Derailleur with X-Horizon and X-Sync technology is among the most reliable options available on the market. Although it is slightly heavier than its pricier siblings, it outlasts the service life of all mountain bike components.

You may also be interested to read about Best Road Bike Groupsets Review

Its side swing technology draws the cable from the top of the frame and creates a 15% larger gap between tire and tube. In this way, it makes the gear shifting precise and smooth.

Also, this cable routing mechanism significantly reduces the force required for gear shifting and enhances the results in easy gear changes and more powerful gear shifts. In addition to ultra-smooth gear shifts, this Shimano Front derailleur has incredible traction and reduced rubbing making it a perfect choice for long-distance rides.

Another standout feature of these MTB derailleurs is impressive ground clearance. Since it has good ground clearance, it is an excellent choice for larger wheels of Enduro and mountain bikes.

If your frame is not compatible with E-mount type drivetrains, we have good news for you. You can buy the same derailleur cage with a regular mounting mechanism with the same build quality and specification in the Shimano XTR FD series.

Concluding SHIMANO Deore XT FD-M8000 MTB Derailleur Review

Shimano XTR FD-M8000 is among the most advanced front MTB derailleurs. It is equipped with Shimano’s long-awaited side swing technology and improved cable routing for precise, reliable, effortless, and smooth gear shifting on all terrain types.

You can also go through a detailed comparison of Shimano Sora and Tiagra Groupsets

Unlike Shimano’s side mount front derailleurs that lack compatibility with outdated frames, it comes with a dual-pull design. This derailleur features an alternative cable stop position and is easily adjusted with both top and bottom cable routing. However, we noticed some minor issues while using it with a top-mount frame dimension. So if you have a bottom-mount cable routing, this is definitely a way to go.

The mounting is quick and easy and won’t take you much time if you have done it before. However, mounting it along with shims may give you a tough time, and it is advised to go to a nearby workshop for quick and damage-free mounting. The best thing we experienced while using this derailleur was the smooth and effortless gear shifting.

The patented Shimano design, coupled with its lightweight structure and wide linkage, significantly reduces friction. The reduced friction and impressive traction minimize the effort required for gear shifting, making it an excellent choice for downhill riding and advanced stages of enduro racing.

Additionally, the aluminum and steel construction makes it exceptionally rigid for improved stability and long-term performance. The derailleur is available in only silver color, and the package includes all the required adapters for a ready-to-go experience. Finally, it is backed by Shimano’s three-year warranty, making it a safe and future-proof investment.

Concluding SHIMANO Unisex’s FDM313X6 Derailleur Review

Shimano FDM313X6 front derailleur is one of the most versatile derailleurs that are compatible with almost all frame dimensions and drivetrains. With a low friction design, straightforward clamp mounts, and competitive price, this is one of the best derailleurs for mountain bike you can get.

The feature that made us add this derailleur to this list was its smooth and easy gear shifting. This accessory weighs only 4.2 oz., and its long cage significantly reduces the friction making the gear shift smooth, quiet, and effortless.

The minimum cog size is 11T, and the maximum cog size is 34T offering a total chain wrap capacity of 45T, which is not much impressive but okay considering its application in the less demanding applications.

It is a 9-speed derailleur, and its long cage design reduces the chances of chain slapping on sprockets, making it ideal for downhill riding. The package includes everything you may need to mount this derailleur, and it took us less than 30 minutes to get everything fixed.

Concluding SRAM X4 Derailleur Review

If you are looking for an affordable rear derailleur with a reliable brand name value, SRAM’s X.4 is the ultimate choice for you. This is an excellent aftermarket derailleur that combines extensive compatibility with a durable build and can outlast the lifespan of other MTB components.

What To Look For While Choosing Derailleur For Your MTB

When buying an aftermarket MTB derailleur, you need to consider certain factors like compatibility with other bike components, cage length, number of speeds, gear ratio, installation mechanism, and many more. To help you choose the best MTB derailleur, we have composed this guide that discusses everything you need to know about an MTB derailleur.

Cage Length of a Derailleur

The cage length is among the most critical features of any MTB derailleur. The cage length dictates the range of gears that you can have after mounting the derailleur. A wider gear range offers more leverage and enhances stability over challenging terrains. MTB derailleurs come with three cage lengths, short, medium, and long.

If you own a mountain bike with a wide range of gears, it is advised to go with a long cage. A medium cage also works well for downhill riding and cross country rides. Short cage derailleurs are not suitable for mountain bikes since they are made for road bikes having dual chainrings.

Compatibility

When buying an aftermarket component, compatibility should be at the top of your priority list. An aftermarket derailleur should be of the same generation and profile as of the other components on your bike. SRAM derailleurs are expensive, but they offer unappalled compatibility with a wide range of MTB drivetrains. Their 8-speed and 9-speed derailleurs are fully compatible with most of the MTBs.

Also, they have 10-speed derailleurs that are fully compatible with road shifters. Shimano derailleurs are also reliable if you have Shimano drivetrains. If your drivetrain is other than Shimano, you will need to install shifters to make the Shimano derailleurs compatible with the remaining bike comments. Also, the pull-type and mounting design should be fully compatible with the frame dimension of the bike.

Clutches

Clutch is another critical factor while looking for an MTB derailleur. Outdated derailleurs used a pivot to provide automatic tension; however, they are less efficient than clutch-based derailleurs. A clutch-based derailleur lets you adjust the chain tension and keep the chain in place even in challenging conditions.

The customized tension in the chain reduces the friction and makes the gear shifting super smooth, quiet, and less challenging. A pivot-based design is okay if you’re buying a front derailleur, but for a rear derailleur, it is highly recommended to buy a clutch-based derailleur.

Weight of a Derailleur

Weight is another important factor since it has a significant impact on-bike performance. Mountain Bike derailleurs are supposed to be lightweight since they are used in demanding applications. However, lightweight derailleurs are more expensive than heavy ones and offer impressive stability over challenging rides. If you love to go on challenging rides, buying a carbon or aluminum derailleur is recommended. Steel derailleurs are also rugged but heavier than carbon and aluminum, making them less suitable for challenging applications.

Gear Ratio and Tooth Capacity

These two factors significantly affect the drivetrain’s ability to deal with rough conditions. The tooth capacity of the derailleur determines the gear range of the derailleurs. If you love off-roading, you must look for a 50T+ tooth capacity for maximum gear shifts. The maximum number of gears you need depends on the number of speeds your bike has. Many online calculators let you calculate the exact gear ratio you need for your bike.

Ease Of Derailleur Installation

Ease of installation and mounting is another key feature you should consider. A direct mount or clamp mount derailleur is pretty easy to install. An easy to mount derailleur makes it easy to maintain the drivetrain and fix the chain issues that may appear during challenging off-road rides.

What is the best derailleur for MTB?

Sram NX Eagle 12-Speed Rear Derailleur is one of the best derailleur for mountain bike. This derailleur is one of the least expensive options in the Eagle series and offers an incredible price to performance ratio. It features SRAM X-Horizon and X-sync technology for maxim precision and accuracy.

Wrapping Up Mountain Bike Derailleurs Review

In this review, we have included both front and rear MTB derailleur at a wide span of prices to help you find the best option. Also, the derailleurs added to our lists are tested for quality and performance and feature the best brand name value. To make your way even easier, here are the two we liked most.

• Shimano Deore XT RD-M786 SGS Shadow Plus Rear Derailleur for its SGS on pulley cage, competitive price, stabilizer switch to prevent chain slap, direct mount design, and switch-based clutch.
• Sram NX Eagle 12-Speed Rear Derailleur for ist 12-speed long cage, affordable price, X-sync technology, and ultra-smooth gear shifts.

Shimano and SRAM are the two most trusted brands if you are looking for reliable aftermarket bike components. SRAM’s derailleurs are more versatile and offer impressive compatibility with both new and outdated frame designs. However, if you have Shimano drivetrains, Shimano derailleurs are ideal since they are less expensive than SRAM’s derailleurs.