Shimano Ultegra ST-R8170/BR-R8170 Di2 gear shift/hydr. brake, left, 2x12, Flat Mount, 1 000 mm hose

WARNING
For information on installation, adjustment and replacement of the products which are not found in the user's manual, consult the place of purchase or a distributor. A dealer's manual for professional and experienced bicycle mechanics is available on our website (https://si.shimano.com).
For safety, be sure to read this "user's manual" thoroughly before use, follow it for correct use, and save it so that you can refer back to it at any time.
The following instructions should always be followed in order to prevent personal injury, damage to equipment or damage to the surroundings. The instructions are classified according to the degree of danger or damage which may occur if the product is used incorrectly.
DANGER - Failure to follow the instructions will result in death or serious injury.
WARNING - Failure to follow the instructions could result in death or serious injury.
CAUTION - Failure to follow the instructions could result in personal injury, or physical damage to equipment and surroundings.

WARNING
- Because each bicycle may handle slightly differently, depending on the model, be sure to learn the proper braking technique (including pressure on the brake lever and bicycle control characteristics) and operation of your bicycle. Improper use of the bicycle's brake system may result in a loss of control, which could lead to a serious injury due to falling or collision.
- Do not disassemble or modify the product. It may cause the product to not operate correctly, and you may fall unexpectedly and be seriously injured.
- Do not subject the product to strong impact or throw it. Failure to do so may cause cracking, overheating, or problems during operation.
- Prevent grease from adhering to the metal terminals. It may cause wire connection failure.
- Use only the specified button batteries. When replacing the button battery, replace both batteries with new ones at the same time. Using different types of button batteries or new and old button batteries together may cause the button batteries to burst, leak fluid, overheat, or ignite, which may lead to fire, injury, or contamination of the surroundings.
- Button batteries are dangerous and must be kept out of the reach of children. Never put batteries in your mouth or any part of your body. If swallowed or placed inside the body, serious or fatal injuries can occur within 2 hours. If this occurs or is suspected, seek immediate medical attention.
- Do not use this equipment in locations where children may be present. In the event that the supplied button batteries are accidentally swallowed, seek medical attention immediately.
- Dispose of button batteries in accordance with applicable local and/or state regulations governing disposal. Disposing of this product in a fire or a hot oven, or mechanically crushing or cutting it, may result in an explosion of the button batteries.
- Do not use button batteries outside of the specified operating temperature ranges. Using or storing the battery at temperatures outside of these ranges may cause fire, injury, or problems during operation.
- Do not use button batteries if it exhibits liquid leakage, discoloration, deformation, or any other atypical signs. Failure to do so may cause cracking, overheating, or problems during operation.
- If leaking fluid from the button batteries gets on your skin or clothing, immediately clean it off with clean water. The leaking fluid may damage your skin.
- Do not leave this product in an environment with extremely high temperature, such as in a closed vehicle during a hot day, or near a heater. This could cause the button batteries to explode, or flammable liquid or gas to leak from them.
- Do not subject this product to extremely low air pressure. This could cause the button batteries to explode, or flammable liquid or gas to leak from them. Air transport of this product is not a problem.
- When operating the shift switch, be careful that your fingers do not get caught in the derailleur. The powerful motor that drives the electronic gear shift derailleur will run without stopping until the shift position is reached.
- This hydraulic brake system has braking characteristics that are different from those of the rim brake type, indicating a relatively large braking force at the start of braking (higher than with the rim brake type); before use, sufficiently familiarize yourself with the braking characteristics. If you ride the bicycle without sufficiently familiarizing yourself with the braking characteristics, braking may result in the bicycle falling over, possibly resulting in serious injury or a fatal accident.
- The braking force of the hydraulic brake system will increase along with the size of the disc brake rotor (140 mm, 160 mm, 180 mm, 203 mm).
- Do not use a 203 mm disc brake rotor. This will excessively increase the braking force, which may cause you to lose control of the bicycle, fall, and be seriously injured.
- Use a 180 mm disc brake rotor only if you cannot obtain sufficient braking force with a 160 mm disc brake rotor during a test ride, such as when riding a road e-bike or if the rider is heavy. Otherwise, you may lose control of the bicycle, fall, and be seriously injured.
- If you feel that the braking force is too strong or too weak, stop using it and consult the place of purchase or a distributor. Accidents or falls may occur due to loss of control of the bicycle, which may result in serious injury.
- Keep your fingers well away from the rotating disc brake rotors. The disc brake rotor is sharp enough to cause severe injury to your fingers if your fingers get caught in the openings of a moving rotor.
- Do not touch the calipers or disc brake rotor during or immediately after riding the bicycle. The calipers and disc brake rotor become hot during braking, so you may be burned if you touch them.
- Do not allow any oil or grease to get onto the disc brake rotor and brake pads. If oil or grease get onto the brake pads, have the brake pads replaced. Riding the bicycle with oil or grease on the brake pads may cause the brakes to not work, and this may result in a serious injury due to falling or collision.
- Check the brake pad thickness and do not use the brake pads if they are at a thickness of 0.5 mm or less. Doing so may cause the brakes to not work, and this may result in a serious injury.
- Do not use the disc brake rotor if it is cracked or deformed. The disc brake rotor may break, leading to a serious injury caused by falling.
- Do not use the disc brake rotor if its thickness is 1.5 mm or less. Also, do not use it if the aluminum surface is visible. The disc brake rotor may break, leading to a serious injury caused by falling.
- Do not apply the brakes continuously. Doing so may cause a sudden increase in brake lever stroke, causing the brakes to not work, and this may result in a serious injury.
- Do not apply the brakes if there is fluid leakage. Doing so may cause the brakes to not work, and this may result in a serious injury.
- Do not apply the front brake too strongly. If you do so, the front wheel may lock and the bicycle may topple forward, causing serious injury.
- Because the required braking distance will be longer during wet weather, reduce your speed. Apply the brakes early and gently. You may fall or collide and be seriously injured.
- A wet road surface can cause the tires to lose traction. To prevent this, reduce your speed and apply the brakes early and gently. If the tires do lose traction, you may fall and be seriously injured.

CAUTION
- Cautions regarding SHIMANO genuine mineral oil
- If it gets in your eyes, flush your eyes with clean water and seek immediate medical attention. Contact with the eyes may cause irritation.
- If it gets on your skin, wash it off thoroughly with soapy water. Contact with the skin may cause rashes and discomfort.
- Protect your nose and mouth with a protective breathing mask, and use in a well-ventilated room. Inhaling mineral oil vapor or mist may cause nausea.
- If you inhale mineral oil vapor or mist, immediately move to a place where there is fresh air. Cover yourself with a blanket. Stay warm in a stable position, and seek professional medical assistance.
Warm-up period
- Disc brakes have a bedding-in period, and the braking force will gradually increase along with the increasing bedding-in period. Accidents or falls may occur due to loss of control of the bicycle, which may result in serious injury. The same situation occurs when replacing the brake pads or disc brake rotor.