Recommended Use

Activity

Actuation

Drivetrain Speed

Cage Length

bottomline

Shimano

It all started with freewheels. The year was 1921 when Shozaburo Shimano established Shimano Iron Works, in Sakai City, Japan. It's a city steeped in metalworking history—once a major center for sword making and still home to a thriving cutlery industry, it's a fitting birthplace for Shimano. Having access to a world-class workforce allowed the company to build its first product, a high-quality freewheel, which required manufacturing techniques that at the time were cutting edge. Today, Shimano's bicycle components are trusted around the world for their quality and reliability. Shimano manufactures components for nearly every application, from professional racing to recreational cycling.<br><br>Although it’s the world's largest manufacturer of cycling components, Shimano stays nimble when it comes to product development, always looking for ways to think outside the box.  It’s this brand of innovative thinking that led to the introduction of the STI integrated shifter/brake lever combo in 1989, which singlehandedly ended the era of downtube shifters. Or the SPD clipless pedal, which has earned a diehard following in the past three decades, and whose modern descendants share the same basic design as the original. Then there's Di2 electronic shifting, which has been proven at the top levels of professional road and cyclocross racing. And with the advent of disc brakes for road bikes, Shimano continues to lead the market.<br><br>Shimano is best known for component groups that cater to the full range of cyclists. In fact, Shimano pioneered the concept of the modern groupset (shifters, derailleurs, cassettes, and chains); it has since become standard industry practice to offer complete drivetrains. Shimano’s pro-level Dura Ace road bike and XTR cross-country mountain bike groupsets act as a proving ground for new technologies and weight-saving measures. The second-tier Ultegra road and XT mountain groups are functionally on par with Dura Ace and XTR, with some concessions made to weight savings. Technologies and innovations quickly trickle down throughout the component family tree;  middle-tier components like the Deore and SLX mountain groups, or the 105 road groups, are in some ways superior to their pro-level counterparts from only a few years ago. <br><br>In addition to drivetrain components, Shimano builds both hubs and complete system wheelsets as well as a full line of cycling shoes and mountain bike shoes. Despite the wide variety of products offered, each product group receives the same fanatical attention to detail to ensure that it's a class leader. In other words, the Shimano logo means you're getting a product that's backed by nearly a century of history, and executed to perfection. 

Shimano is best known for component groups that cater to the full range of cyclists. In fact, Shimano pioneered the concept of the modern groupset (shifters, derailleurs, cassettes, and chains).

Shimano Cycling Components & Apparel

Shozaburu Shimano founded Shimano Iron Works in 1921, in the industrial hub of Sakai City, Japan. Starting with high quality bicycle freewheels, Shimano's exceptional metalworking abilities and precision manufacturing earned them accolades, and was the foundation upon with Shimano's reputation still rests today. <br><br>Today, Shimano is the world's largest manufacturer of cycling components, but that position as market leader hasn't stifled the culture of innovation. From the STI integrated shifter/brake lever combo in 1989, which made downtube shifters obsolete nearly overnight, to the SPD clipless pedal, Shimano has introduced some of the most important components of the modern era. More recently, Di2 electronic drivetrains are carrying the torch, proving themselves a competitive advantage in the top levels of road, cyclocross, and mountain bike racing. <br><br>Shimano is best known for component groups for all cyclists. In fact, Shimano originally pioneered the idea of designing shifters, derailleurs, cassettes, and chains as part of a groupset—a practice that's now the defacto standard in the industry. The pro-level Dura Ace road bike and XTR cross-country mountain bike groupsets represent the pinnacle of manufacturing and technology. The second-tier Ultegra road and XT mountain groups are renowned workhorses that benefit from technologies borrowed from the top tier groups. Even middle-tier components like the Deore and SLX mountain groups, or the 105 road groups, provide quantifiable advantages over thier pro-level counterparts from only a few years ago. Shimano also builds both hubs and complete wheelsets, plus a full line of cycling shoes and mountain bike shoes. 

Shimano derailleurs, cranksets, brakes, and shift levers prove that you needn't resort to carbon fiber if you're looking for peerless shifting and braking quality.

Shimano Cycling - Wheels, Parts, & More

It all started with freewheels. The year was 1921 when Shozaburo Shimano established Shimano Iron Works, in Sakai City, Japan. It's a city steeped in metalworking history—once a major center for sword making and still home to a thriving cutlery industry, it's a fitting birthplace for Shimano. Having access to a world-class workforce allowed the company to build its first product, a high-quality freewheel, which required manufacturing techniques that at the time were cutting edge. Today, Shimano's bicycle components are trusted around the world for their quality and reliability. Shimano manufactures components for nearly every application, from professional racing to recreational cycling.
<br><br>
Although it’s the world's largest manufacturer of cycling components, Shimano stays nimble when it comes to product development, always looking for ways to think outside the box.  It’s this brand of innovative thinking that led to the introduction of the STI integrated shifter/brake lever combo in 1989, which singlehandedly ended the era of downtube shifters. Or the SPD clipless pedal, which has earned a diehard following in the past three decades, and whose modern descendants share the same basic design as the original. Then there's Di2 electronic shifting, which has been proven at the top levels of professional road and cyclocross racing. And with the advent of disc brakes for road bikes, Shimano continues to lead the market.
<br><br>
Shimano is best known for component groups that cater to the full range of cyclists. In fact, Shimano pioneered the concept of the modern groupset (shifters, derailleurs, cassettes, and chains); it has since become standard industry practice to offer complete drivetrains. Shimano’s pro-level Dura Ace road bike and XTR cross-country mountain bike groupsets act as a proving ground for new technologies and weight-saving measures. The second-tier Ultegra road and XT mountain groups are functionally on par with Dura Ace and XTR, with some concessions made to weight savings. Technologies and innovations quickly trickle down throughout the component family tree;  middle-tier components like the Deore and SLX mountain groups, or the 105 road groups, are in some ways superior to their pro-level counterparts from only a few years ago.
<br><br>
In addition to drivetrain components, Shimano builds both hubs and complete system wheelsets as well as a full line of cycling shoes and mountain bike shoes. Despite the wide variety of products offered, each product group receives the same fanatical attention to detail to ensure that it's a class leader. In other words, the Shimano logo means you're getting a product that's backed by nearly a century of history, and executed to perfection.


The Ultegra Di2 RD-RX805 Rear Derailleur is meant to take on all the rigors of rough road and gravel riding. Its clutch system improves shifting and reduces noise from chain slap, and there's compatibility with both 1x and 2x drivetrains and Shimano Di2 shifters. Experience smooth Di2 electronic shifting, a quiet ride and a good time.

Detail

Material

Capacity

Cassette Range

Gearing

Compatibility

Claimed Weight

Manufacturer Warranty

Ultegra Di2 RD-RX805 Rear Derailleur

Discount applies to full-price items only. 

Get the scoop on sales and gear

15% off when you sign up for email

Bikes

Custom Builds

Brands

Road

Mountain

Triathlon

Accessories

Women

Wheels, Tires, Tubes

Drivetrains, Brakes

Forks, Cockpits, Pedals

Components

Bike Essentials

Maintenance & Transportation

Performance

Just In

Mens

Womens

Bike Components

Sale

CC X L39ION

Learn

By submitting this form, you agree to receive recurring automated promotional and personalized marketing text messages (e.g. cart reminders) from Backcountry at the cell number provided when signing up. Consent is not a condition of any purchase. Msg frequency varies. Msg. and data rates may apply. 

First dibs on products, sales & exclusives

Sign up for text alerts & get 15% off

Shimano
Ultegra Di2 RD-RX805 Rear Derailleur

Out of Stock

Why We Like The Ultegra RD-RX805 Rear Derailleur

Details

Tech Specs