How to Install, Adjust, and Maintain the Shimano BR-R8170 Disc Brakes

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in Brakes, Shimano, Ultegra

The Shimano BR-R8170 [paid link] disc brakes are part of the Ultegra R8100 series, designed for road cyclists who demand smooth modulation, consistent braking power, and reliable performance. These hydraulic disc brakes are a step up in Shimano’s braking technology, featuring a refined piston design, better heat dissipation, and improved clearance between the rotor and pads.

In this guide, we’ll cover everything you need to install, adjust, and maintain your Shimano BR-R8170 [paid link] brakes. Whether you’re setting them up for the first time or troubleshooting common issues, this article will help you ensure optimal braking performance.

Tools Required [paid links]

Before you begin, gather the following tools:

Shimano BR-R8170 Disc Brake Installation Guide

1. Mounting the Calipers

  1. Ensure your bike frame and fork are flat-mount compatible with the Shimano BR-R8170 [paid link] calipers.
  2. Align the caliper mounting holes with the frame’s brake mount.
  3. Insert the fixing bolts and lightly tighten them using a 5mm Allen wrench [paid link].
  4. Center the caliper by squeezing the brake lever while tightening the bolts to the recommended torque (6–8 Nm).

2. Installing the Rotors

  1. If using Shimano RT-MT800 or RT-CL800 rotors, mount them on the hub using a center lock adapter or a 6-bolt system.
  2. Use a T25 Torx wrench [paid link] to secure the bolts or Shimano’s lockring tool [paid link] for center lock rotors.
  3. Torque the rotor bolts to 5–6 Nm to avoid warping.

3. Connecting the Hydraulic Hose

  1. Cut the hydraulic hose to the correct length using Shimano’s hose-cutting tool.
  2. Insert the olive and barb fitting into the hose end.
  3. Push the hose into the brake lever and secure it with the compression nut (tighten to 5–7 Nm).
  4. Perform a brake bleed to remove any air from the system (covered below).

4. Attaching the Brake Pads and Securing the System

  1. Slide the L05A-RF resin or L04C metal brake pads into the caliper.
  2. Insert the pad retention bolt and torque it to 2–3 Nm.
  3. Squeeze the brake lever multiple times to set the pistons in place.

Adjusting Shimano BR-R8170 Disc Brakes

1. Caliper Alignment

If your rotors rub against the pads, adjust the alignment:

  • Loosen the caliper bolts slightly.
  • Spin the wheel and apply the brake lever firmly.
  • While holding the brake, tighten the caliper bolts evenly.

2. Lever Reach Adjustment

The BR-R8170 levers allow reach adjustment to accommodate different hand sizes:

  • Use a 2mm Allen key on the adjustment bolt near the lever pivot.
  • Turn clockwise to bring the lever closer; counterclockwise to extend.

3. Rotor Truing

If you notice pulsating or uneven braking, check the rotor for warping:

  • Use a rotor truing tool to gently bend misaligned sections.
  • Clean the rotor with isopropyl alcohol to remove contamination.

Bleeding Shimano BR-R8170 Hydraulic Disc Brakes

Shimano hydraulic brakes require periodic bleeding to remove air bubbles and ensure optimal performance.

1. Setting Up the Bleeding Process

  1. Secure the bike on a repair stand and keep the lever level [paid link].
  2. Remove the reservoir plug and attach the Shimano bleed funnel.

2. Bleeding Procedure

  1. Fill the bleed cup with Shimano mineral oil [paid link].
  2. Open the caliper bleed port using a 7mm wrench and attach a bleed syringe.
  3. Slowly push oil through the system until air bubbles stop appearing in the funnel.
  4. Close the bleed port and remove the funnel.
  5. Wipe excess oil and test the brakes.

Maintenance Tips for Long-Lasting Performance

1. Cleaning Your Brakes Regularly

  • Wipe rotors with isopropyl alcohol to prevent contamination.
  • Check for brake fluid leaks around the calipers and levers.

2. Checking Pad Wear

  • Replace brake pads when the thickness is below 0.5mm.
  • Always use Shimano L05A-RF resin or L04C metal pads for optimal performance.

3. Inspecting Brake Hoses and Connections

  • Look for signs of leaks or cracks in the hose.
  • If braking feels spongy, check for air in the system and rebleed if necessary.

Troubleshooting Common Shimano BR-R8170 Brake Issues

1. Squealing or Noisy Brakes

  • Clean the rotors and pads with isopropyl alcohol.
  • Sand down glazed pads with fine-grit sandpaper.

2. Brake Lever Feels Spongy

  • Air might be trapped in the system—bleed the brakes.
  • Ensure the hose fittings are properly sealed.

3. Rotor Rubbing on the Pads

  • Re-align the caliper using the loosen-and-squeeze method.
  • Check if the rotor is bent and true it if necessary.

Shimano BR-R8170 vs. Shimano BR-R9270: Key Differences

  • BR-R8170 (Ultegra) vs. BR-R9270 [paid link] (Dura-Ace)
    • BR-R9270 [paid link] has lighter construction and better heat dissipation.
    • BR-R8170 offers almost identical performance at a lower cost.

Conclusion

The Shimano BR-R8170 disc brakes provide excellent modulation and power for road cyclists. By following this guide, you can install, adjust, and maintain your brakes for maximum performance. Regular cleaning, pad checks, and fluid maintenance will ensure long-lasting, reliable braking on every ride.