Shimano Total Integration (STI) is a gearshift system designed by Shimano

Shimano

Shimano, Inc. is a Japanese multinational manufacturer of cycling components, fishing tackle, and rowing equipment.In 2005, the company had net sales of US $1.4 billion. Bicycle components provided 75% of its sales income...

 for racing bicycle

Racing bicycle

A racing bicycle, also known as a road bike, is a bicycle designed for competitive road cycling, a sport governed by according to the rules of the Union Cycliste Internationale...

s. It combines the braking and gear shifting controls into the same component. This allows shifting gears without having to remove a hand from the bars, unlike previous down tube shifting systems. This component is usually referred to as a "shifter

Shifter (bicycle part)

A bicycle shifter or gear control or gear levers is a component used to control the gearing mechanisms and select the desired gear ratio. Typically, they operate either a derailleur mechanism or an internal hub gear mechanism. In either case, the control is operated by moving a cable that connects...

" or "dual-control levers", or occasionally "brifters".

In 1989, Shimano introduced their "Rapidfire" shifting for mountain bike

Mountain bike

A mountain bike or mountain bicycle is a bicycle created for off-road cycling. This activity includes traversing of rocks and washouts, and steep declines,...

s. This brought indexed shifting to the handlebars - something previously only available on downtube shifters or thumb shifters. This mechanism operates like a ratchet, the larger lever applying tension to the gear cable, the smaller one incrementally releasing it. The Rapidfire mechanism was subsequently adapted to be used in STI levers.

In 1990, Shimano introduced their STI shifting levers for road bicycle

Road bicycle

The term road bicycle is used to describe bicycles built for traveling at speed on paved roads. Some sources use the term to mean racing bicycle...

s, which completely integrated the brake lever and shifter. It also redesigned the brake "hoods" where riders commonly rest their hands. This new design worked like a normal brake lever in the longtitudinal plane, but also allowed the rider to shift to a larger cog

Cog

Cog may refer to:* A part of a gear system* Cog , a small sailing vessel* A tenon that extends all the way through another piece of wood, in joinery* The evil robots in Toontown Online...

 by pushing the lever so that it pivots laterally. Behind the brake lever, there is a smaller lever that shifts to a smaller cog when pushed towards the inside.

This system helped Shimano take the lead in groupset

Groupset

A groupset or gruppo is a bicycle component manufacturer's organized collection of mechanical parts...

 manufacturing.
Around the same time, the other major global producer in bicycle components, Campagnolo

Campagnolo

Campagnolo is an Italian manufacturer of high-end bicycle components with headquarters in Vicenza, Italy. The components are organised as groupsets and are a near-complete collection of a bicycle's mechanical parts. Campagnolo's flagship components are the Super Record, Record, and Chorus...

, collaborated with the Sachs company to produce their ErgoPower

Campagnolo ErgoPower

Campagnolo ErgoPower is an integrated gearshift and brake lever system designed by Campagnolo for racing bicycles. It allows shifting gears without having to remove a hand from the bars, unlike previous down tube shifting systems. It was launched in 1992 to compete with Shimano Total Integration...

 system, differing substantially in its design and operation.

In 2003, Shimano introduced "dual-control levers" or STI for mountain bikes in their XTR groupset. Like the road shifters, XTR used the same lever for braking and shifting. This was met with some resistance as they limited the choice of disc brakes to only those made by Shimano. They are nicknamed, "flippity shifters" for the brake lever's ability to move in the vertical plane.

STI and ErgoPower have largely displaced downtube shifting, even though some cyclists still use downtube shifters for various reasons, including less expense, less weight, more flexibility, and better reliability. A compromise is to use bar-end shifters or Barcons. This type places the shifters closer to the hand positions, but still offer a simple reliable system, especially for touring cyclist. Drawbacks to STI and ErgoPower systems include the higher weight and the higher price. There are many more parts in an STI or ErgoPower lever than in a downtube system.

Since the creation of the STI shifting system the main improvements have included reducing weight and increasing cog count. Weight savings have come from using new materials such as Duralumin

Duralumin

Duralumin is the trade name of one of the earliest types of age-hardenable aluminium alloys. The main alloying constituents are copper, manganese, and magnesium. A commonly used modern equivalent of this alloy type is AA2024, which contains 4.4% copper, 1.5% magnesium, 0.6% manganese and 93.5%...

 in Shimano's component groups and carbon fiber in Campagnolo

Campagnolo

Campagnolo is an Italian manufacturer of high-end bicycle components with headquarters in Vicenza, Italy. The components are organised as groupsets and are a near-complete collection of a bicycle's mechanical parts. Campagnolo's flagship components are the Super Record, Record, and Chorus...

's parts.

Some cyclists, including Lance Armstrong

Lance Armstrong

Lance Edward Armstrong is an American former professional road racing cyclist who won the Tour de France a record seven consecutive times, after having survived testicular cancer. He is also the founder and chairman of the Lance Armstrong Foundation for cancer research and support...

, installed a standard STI shifter on climbing-specific bikes for the cassette and a downtube shifter for the chainrings in order to reduce weight. This is done because chain is shifted across the cassette much more often than the chainrings. This setup might save up to 200 grams (7 ounces) off the total bike weight. Compared to the minimum legal racing weight permitted by the Union Cycliste Internationale

Union Cycliste Internationale

Union Cycliste Internationale is the world governing body for sports cycling and oversees international competitive cycling events. The UCI is based in Aigle, Switzerland....

, 6.8 kilograms (15 pounds), 200 grams is about 3% of the total weight.