Shimano 105, Ultegra, Dura Ace; GRX Brake Issues: Noise, Rubbing & Fixes
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Shimano’s 105, Ultegra, Dura Ace (road groupsets), and GRX (gravel groupset) hydraulic disc brakes are among the best on the market. However, riders often report common issues like brake noise, rotor rubbing, and inconsistent lever feel.
Common Shimano Brake Issues & Fixes
1️⃣ Brake Noise & Squealing
Brake noise is common in wet conditions, but water, contamination, wear, bedding and alignment can all affect it.
Common Causes:
- Contaminated pads or rotors (oil, grease, or road grime)
- Improper bed in of new pads
- Glazed pads from overheating
Fixes:
- Clean the rotor using Shimano’s approved method. Replace pads contaminated with oil or grease.
- Follow Shimano’s bedding procedure in a safe area; bedding cannot repair contaminated pads or a hydraulic fault.
- Inspect glazed pads and replace them if required by the brake manufacturer’s guidance. Do not sand oily pads as a repair.
- Only use sintered pads where both the caliper and rotor permit them. Some Shimano components are resin only.
2️⃣ Rotor Rubbing & Pad Drag
Shimano’s tight pad to rotor clearance means even slight misalignment can cause rubbing.
Common Causes:
- Caliper misalignment
- Bent rotors
- Lazy piston (one piston retracts slower)
Fixes:
- Re center the caliper: Loosen bolts, squeeze the brake lever, and tighten bolts while holding the lever
- True the rotor using a Gorilla Brakes Rotor Truing Tool
- Follow the exact Shimano procedure for piston movement and reset. Do not use generic lubrication, force or bleed screw shortcuts.
3️⃣ Spongy Brake Feel & Bite Point Issues
If your brake lever feels soft or inconsistent, air bubbles in the hydraulic system could be the cause.
Common Causes:
- Air bubbles trapped in hydraulic lines
- Old or contaminated brake fluid
- Heat buildup on long descents
Fixes:
- If diagnosis shows a bleed is needed, use the exact model’s procedure, compatible equipment and specified Shimano oil. Do not mix standard Shimano hydraulic mineral oil with low viscosity oil or DOT fluid.
- Upgrade to finned pads and Ice Tech rotors for better cooling
- Only increase rotor size within the frame, fork and brake limits, using the specified adapter.
Shimano Brake Comparison Table
| Model | Pad Clearance | Weight | Brake Feel | Best Use |
|---|---|---|---|---|
| 105 (R7070) | Check exact model specification and setup | Heavier | Firm | Budget road setup |
| Ultegra (R8070) | Check exact model specification and setup | Lighter | Smooth & strong | Performance road |
| Dura Ace (R9170) | Check exact model specification and setup | Lightest | Best modulation | Pro riders |
| GRX RX810 | Check exact model specification and setup | Gravel tuned | Grippy | Gravel & adventure |
Shimano Brake Maintenance Tips
- Clean brake rotors regularly with Gorilla Brakes Disc Brake Cleaner
- Follow the model’s service instructions and fluid condition rather than a universal annual bleed interval.
- Check pad wear regularly. Shimano specifies replacement at 0.5 mm of friction material, or sooner if damaged or contaminated. Confirm caliper and rotor approval before changing compound.
- Use only the fastener preparation and torque specified for the caliper. Keep all grease and oil away from pads and rotors.
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Final Thoughts
Shimano disc brakes are high quality, but proper maintenance ensures optimal performance. By aligning your calipers, bleeding your brakes, and upgrading to better brake pads, you can enjoy smooth, quiet, and powerful braking.
Need help? Contact Gorilla Brakes Customer Support for expert advice!