22/06/2009
Mastering Your Shimano Ultegra ST-R8070 & BR-R8170 Hydraulic Disc Brakes
The advent of hydraulic disc brakes has revolutionised cycling, offering unparalleled stopping power and modulation, especially in demanding conditions. Shimano's Ultegra series, renowned for its blend of performance and value, features the ST-R8070 STI levers and BR-R8170 calipers as a popular choice for road and gravel cyclists. Whether you're a seasoned mechanic or a DIY enthusiast, understanding how to properly install, maintain, and troubleshoot these sophisticated braking systems is crucial for safety and peak performance. This comprehensive guide will delve into the intricacies of the Shimano Ultegra ST-R8070 and BR-R8170, drawing upon available information to help you keep your brakes in optimal working order.
Understanding the Shimano Ultegra ST-R8070 & BR-R8170 System
The Shimano Ultegra ST-R8070 is an integrated brake and shift lever, part of Shimano's Di2 electronic shifting system. It's designed to work seamlessly with the corresponding BR-R8170 hydraulic disc brake calipers. The BR-R8170 caliper is a high-performance hydraulic disc brake caliper known for its robust construction and exceptional stopping ability. These brakes are engineered to provide consistent and reliable braking force across a wide range of weather conditions and terrains, from fast descents to wet, muddy trails. The system's hydraulic nature means that brake fluid is used to transmit force from the lever to the caliper, offering a smoother and more powerful feel than traditional cable-actuated brakes.
Installation and Setup: A Crucial First Step
Correct installation is paramount for the performance and longevity of your Shimano hydraulic disc brakes. While a full installation guide is extensive, here are some key considerations, particularly regarding the brake lever and caliper integration:
Brake Lever Installation (ST-R8070 / BR-R8170 Integration):
- Compatibility: Ensure your frame and fork are designed for flat-mount hydraulic disc brakes.
- Hose Routing: Proper internal or external hose routing is essential. Consult your frame manufacturer's guidelines.
- Bleeding: After connecting the brake hose to the caliper and lever, the system must be bled to remove any air. This is a critical step often requiring specific Shimano bleeding tools and mineral oil.
- Lever Adjustment: Shimano levers typically offer reach adjustment to cater to different hand sizes.
Caliper Installation (BR-R8170):
- Mounting: The BR-R8170 is a flat-mount caliper. Ensure your frame and fork have compatible mounts.
- Rotor Compatibility: Use Shimano-approved rotors (e.g., RT-MT800, RT-CL800) of the correct size for your frame and fork.
- Pad Clearance: Proper alignment of the caliper with the rotor is vital to prevent rubbing and ensure optimal braking.
Maintenance: Keeping Your Brakes in Top Condition
Regular maintenance is key to ensuring your Shimano hydraulic disc brakes perform reliably and safely. Here are some essential maintenance tasks:
1. Pad Inspection and Replacement:
- Wear Check: Periodically inspect the thickness of your brake pads. Shimano pads typically have a wear indicator or a minimum thickness guideline (often around 0.5mm of friction material remaining). Never ride with worn-out pads.
- Replacement: When replacing pads, ensure you use genuine Shimano replacements (e.g., L03A, L04C for resin or metal, depending on the specific model and preference). Clean the caliper and rotor thoroughly after replacement.
2. Rotor Care:
- Cleaning: Keep your rotors clean. Use a dedicated disc brake cleaner or isopropyl alcohol on a lint-free cloth. Avoid touching the braking surface with your bare hands, as natural oils can contaminate the rotor.
- Warping: If you notice a pulsating sensation at the lever, your rotor might be warped. This can sometimes be corrected by carefully straightening the rotor, but replacement is often the best solution.
3. Bleeding the System:
- When to Bleed: Bleeding is necessary when the brake lever feels spongy, the braking power has decreased, or after replacing a hose or caliper.
- Fluid: Shimano hydraulic disc brakes use Shimano genuine mineral oil. Never use DOT fluid, as it will damage the seals.
- Process: The bleeding process involves connecting a syringe to the caliper bleed port and another to the lever's bleed port, then carefully pushing fresh mineral oil through the system to expel air bubbles. This requires specific Shimano bleeding kits (e.g., TL-BR001, TL-BR002).
4. Lever and Caliper Cleaning:
- Regularly clean the exterior of your levers and calipers with a mild soap and water solution or a degreaser suitable for bicycle components. Ensure no cleaning agents come into contact with the braking surfaces.
Troubleshooting Common Issues
Even with proper maintenance, you might encounter issues. Here are some common problems and potential solutions:
| Problem | Possible Cause | Solution |
|---|---|---|
| Spongy Brake Lever | Air in the hydraulic system | Bleed the brakes with fresh Shimano mineral oil. |
| Brake Rubbing | Misaligned caliper, bent rotor, or pads too close | Realign caliper, check rotor for warping, adjust pad position if possible. |
| Reduced Braking Power | Worn pads, contaminated pads/rotors, air in system | Replace pads, clean rotors and pads, bleed the system. |
| Squealing Brakes | Contaminated pads/rotors, glazed pads, loose components | Clean thoroughly, bed in new pads, check for loose bolts. |
Important Warnings: What to Avoid
It's crucial to be aware of what can damage your hydraulic disc brake system. The most critical warning relates to contamination:
Can you put oil on disc brake rotor and brake pads? Absolutely NOT.
Getting oil, grease, or any lubricant onto the disc brake rotor and brake pads will severely compromise their performance. Riding a bicycle with oil or grease on these critical components can lead to a significant reduction in braking effectiveness, potentially resulting in serious injury due to a fall or collision. If contamination occurs, the pads and rotor will likely need to be replaced, and the system may require a thorough cleaning and re-bleeding.
Finding Manuals and Resources
For detailed, step-by-step instructions, referring to official documentation is highly recommended. Shimano provides comprehensive manuals for their components. For the Ultegra ST-R8070, you can typically find a Dealer's Manual which contains detailed installation and maintenance procedures. Similarly, for the BR-R8170 caliper, specific manuals detailing its installation and care are available. These can usually be downloaded directly from the official Shimano website.
For example, to install the brake lever of the Shimano BR-R8170 (which integrates with the ST-R8070 levers), you would consult the relevant dealer's manual for the ST-R8070, which will cover the hydraulic connections and bleeding procedures specific to that lever body and its interaction with the BR-R8170 caliper. These manuals often include detailed diagrams and specifications.
Frequently Asked Questions (FAQs)
Q1: What type of oil should I use for my Shimano Ultegra hydraulic brakes?
A: You must use only Shimano genuine mineral oil. Using other types of fluid, especially DOT fluid, will damage the seals and the entire braking system.
Q2: How often should I bleed my hydraulic disc brakes?
A: There's no fixed schedule. You should bleed them when the lever feels spongy, braking performance diminishes, or after replacing hydraulic lines or components.
Q3: My brakes are making a squealing noise. What should I do?
A: Squealing is often caused by contamination or glazed pads. Try cleaning the rotor and pads with disc brake cleaner. If that doesn't work, consider replacing the brake pads and properly bedding them in.
Q4: Can I use non-Shimano brake pads or rotors?
A: While some third-party components might be compatible, it's always recommended to use genuine Shimano parts for optimal performance and to avoid potential issues. Using non-specified parts can void warranties and compromise safety.
Q5: How do I bed in new brake pads and rotors?
A: Bedding in is a process of transferring a thin layer of pad material to the rotor. Typically, this involves a series of moderate-speed stops, gradually increasing the intensity without coming to a complete stop, and allowing the brakes to cool between applications. Consult your Shimano manual for specific bedding-in procedures.
Conclusion
The Shimano Ultegra ST-R8070 and BR-R8170 hydraulic disc brake system offers exceptional stopping power and control. By understanding the importance of correct installation, performing regular maintenance, and being aware of potential issues and their solutions, you can ensure your brakes function reliably and safely for many miles to come. Always prioritise using the correct fluids and parts, and when in doubt, consult the official Shimano documentation or seek assistance from a qualified bicycle mechanic. Happy cycling!
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