Shimano has been refining and redefining shifting performance for more than 70 years. What began with basic external shifting has evolved into some of the most precise and reliable component groupsets in cycling. Today, Shimano’s road and gravel components rely on a suite of integrated technologies designed to deliver consistent, confident shifts every time you press a lever.

Understanding how these technologies work together helps explain why Shimano drivetrains are trusted by everyone from everyday riders to WorldTour professionals.

To understand the design and function of modern Shimano road and gravel groupsets, it’s essential to start with one of our most influential innovations: SHIMANO Total Integration, better known as STI.

SHIMANO Total Integration fundamentally changed how riders interact with their bikes by combining shifting and braking controls into a single, intuitive interface at the handlebars. Before STI, gear changes were controlled by shifters mounted on the downtube, while braking was handled separately by levers on the bars. This setup required riders to remove a hand from the bars to shift, which was especially problematic in fast or technical riding situations.

By moving both braking and shifting controls to a single, easily accessible location, SHIMANO STI dramatically improved rider confidence, control, and safety. Since its introduction more than three decades ago, STI has continued to evolve alongside advancements in drivetrain and braking technology.

Building on the foundation of STI, Shimano developed the DUAL CONTROL LEVER technology (DCL), which represents the next evolution of integrated control for drop-bar bicycles.

While mountain bikes use separate levers for braking and shifting, road and gravel bikes combine both functions into one unit. Every Shimano-equipped drop-bar bike uses DUAL CONTROL LEVER technology, a system Shimano pioneered for performance road and gravel riding.

One of the key benefits of the DUAL CONTROL LEVER technology is its ergonomic design. Drawing durability from Shimano’s mountain bike technologies, the system also allows for exceptionally light and smooth shifting. Front and rear shifts can be executed with a single finger, even under load. This seamless interaction between rider and drivetrain is the purest expression of STI in action.

Di2 is short for Digital Integrated Intelligence and is Shimano’s pinnacle electronic shifting technology. Introduced in 2009, Di2 redefined expectations for precision, speed, and reliability in drop-bar shifting systems and helped establish electronic shifting as the gold standard in performance cycling.

As the most advanced evolution of STI, Di2 delivers instantaneous, accurate gear changes with minimal effort, regardless of conditions. Over the years, Shimano has continued to refine Di2, making it more intuitive, more reliable, and more deeply integrated into the complete drivetrain system.

Every Di2 system is built around a set of electronic components that communicate seamlessly to deliver flawless shifting performance.

• Di2 STI Shifters – The Di2 STI shifters translate rider input into precise electronic commands. Rooted in STI, these shifters combine hydraulic brake control with electronic shift buttons, allowing riders to change gears, control cycle computers, and adjust system settings without moving their hands from the bars. Each shifter is powered by a coin cell battery rather than being wired directly to the main battery, simplifying setup while maintaining reliable performance.

• Di2 Rear Derailleur – The rear derailleur is both the muscle and the brain of modern Di2 systems. In addition to handling most gear changes, it now functions as the system’s communication hub. It stores critical system information and connects wirelessly to the STI levers and the E-TUBE app. A single multifunction button on the derailleur lets riders check battery status, switch shift modes, and pair components. On select models, such as the GRX RD-RX827, the rear derailleur also houses the integrated battery.

• Di2 Front Derailleur – While it shifts less frequently than the rear derailleur, the Di2 front derailleur plays a critical role in drivetrain performance. It moves the chain between chainrings and continuously micro-adjusts its position as the rider shifts across the cassette. This ensures smooth operation and eliminates chain rub, even under load.

• Di2 Battery – On 2x12-speed Di2 systems, the lithium-ion battery connects directly to the front and rear derailleurs, while Shimano 1x12-speed rear derailleurs house an integrated battery directly in the derailleur unit. Each battery's single charge delivers up to 1,000 kilometers of shifting and is rated for at least 300 complete charge cycles. With biweekly charging, that equates to more than a decade of use.

While STI and Di2 technologies translate rider input into action, HYPERGLIDE+ is where that action happens, inside the drivetrain itself. HYPERGLIDE+ is an advanced shifting technology engineered into Shimano chains, cassettes, and chainrings.

HYPERGLIDE+ allows riders to shift into harder gears without easing off the pedals, maintaining continuous engagement between the chain and cassette. The result is faster, smoother, and more secure shifting under load, whether launching an attack, accelerating on a climb, or sprinting at full power.

Specially designed shift ramps guide the chain seamlessly between cogs, eliminating hesitation or momentary disengagement during shifts. Riders no longer need to finesse gear changes, HYPERGLIDE+ enables confident, full-power shifting through every gear.

HYPERGLIDE+ first debuted on Shimano mountain bike cassettes, where it quickly proved its performance advantages. Riders like Tom Pidcock and Pauline Ferrand-Prévot used HYPERGLIDE+ XTR groupsets to claim world championship titles in 2023.

Bringing HYPERGLIDE+ to road drivetrains posed a greater challenge due to the tighter gear spacing of road cassettes. However, backed by more than a century of drivetrain manufacturing expertise (Shimano’s first product was a gear cog released in 1921), engineers successfully adapted this race-winning technology for the road and gravel.