Shimano GRX ST-RX820/BR-820 Dual Control gear shift/hydr. brake, 2-sp., left, Flat Mount, 1 000 mm hose

WARNING
For information on the installation, adjustment and replacement of the products which are not to be 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 directions must be always followed in order to prevent personal injury, physical damage to equipment or damage to the surroundings. The directions are classified according to the degree of danger or damage which may occur if the product is used incorrectly.
DANGER – Failure to follow the directions will result in death or serious injury.
WARNING – Failure to follow the directions could result in death or serious injury.
CAUTION – Failure to follow the directions could cause personal injury or physical damage to equipment and the surroundings.

WARNING
- Because each bicycle may handle differently depending on the model, 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 a fall 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.
- This hydraulic brake system has braking characteristics that are different than those of the rim brake type, which indicates a relatively large braking force at the start of braking (higher than 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 a fall from the bicycle, 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. Doing so will excessively increase the braking force, which may cause you to lose control of the bicycle, fall, and be seriously injured.
- Only use a 180 mm disc brake rotor if you cannot obtain sufficient braking force with a 160 mm disc brake rotor in a test ride, such as when riding an e-road 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, possibly resulting in serious injury.
- Keep your fingers away from the rotating disc brake rotors. The disc brake rotor is sharp enough to cause severe finger injury if 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 you ride the bicycle with oil or grease on the disc brake rotor and brake pads, the brakes may not work, and this may lead to a serious injury due to a fall or collision.
- Check the brake pad thickness, and do not use them if they are at a thickness of 0.5 mm or less. Otherwise, this may cause the brakes to not work, and this may lead to a serious injury caused by a fall or collision.
- 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 a fall.
- 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 a fall.
- Do not apply the brakes continuously. This may cause a sudden increase in the brake lever stroke, cause the brakes to not work, and lead to a serious injury due to a fall or collision.
- Do not use the brakes if there is fluid leakage. This may cause the brakes to not work, and this may lead to a serious injury caused by a fall or collision.
- 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 well in advance 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 well in advance 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 immediately seek medical attention. Contact with the eyes may cause irritation.
- If it gets on your skin, wash it off properly with soap and 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 steam or vapor may cause nausea.
- If you inhale mineral oil steam or vapor, 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 time
-Disc brakes have a certain warm-up time, and the braking force gradually increases along with the increasing warm-up time. Accidents or falls may occur due to loss of control of the bicycle, possibly resulting in serious injury. The same situation will occur when replacing the brake pads or disc brake rotor.