The Shimano BR-6700 [paid link] brakes, part of the Ultegra 6700 series, are well-regarded for their reliable stopping power, progressive modulation, and aerodynamic design. However, if not installed or adjusted correctly, they can underperform—leading to spongy lever feel, poor brake response, uneven pad wear, or even rim damage. Whether you’re setting them up for the first time or troubleshooting inconsistent braking, understanding the nuances of this caliper system is key to restoring optimal performance.
Understanding BR-6700 [paid link] Brake Design
The BR-6700 [paid link] uses a dual-pivot design that improves braking power compared to its predecessors. Its symmetric arm construction enhances modulation and balances braking force across both pads. However, to unlock its full potential, precise set-up is non-negotiable. Even minor misalignments can affect lever throw, pad engagement, and braking consistency—especially under load or in wet conditions.
Common Signs of Incorrect BR-6700 Brake Setup
Improper setup can present in several forms. Riders may experience:
- Inconsistent braking response, especially between front and rear.
- Brake pads rubbing the rim, even when the brake lever is not engaged.
- Soft or spongy lever feel, indicating excessive cable slack or poor pad contact.
- Uneven pad wear, caused by misaligned pad surfaces.
- Reduced stopping power, despite proper lever pull.
These symptoms are not inherent flaws in the BR-6700 design. Instead, they often stem from overlooked setup steps or compatibility issues during installation or adjustment.
Typical Installation Errors That Affect Performance
Improper cable tensioning is among the most frequent causes of poor performance. With the BR-6700, cable tension must be tight enough to allow immediate pad engagement, yet loose enough to prevent pad drag. Many mechanics err on the side of caution and leave too much slack, resulting in a delayed brake response.
Another common issue lies in pad alignment. The BR-6700 calipers require pads to sit flush against the rim’s braking surface with a slight toe-in—meaning the front of the pad should touch the rim just before the rear during engagement. This prevents squealing and enhances modulation. Misaligned pads not only impair stopping efficiency but can also accelerate rim and pad wear.
Brake caliper centering is often neglected as well. The BR-6700 uses a centering bolt accessible from the front of the caliper arm. Without centering, one pad may engage before the other, reducing braking symmetry and power.
Correcting Poor Set-Up: A Step-by-Step Diagnostic
To address improper setup, begin by releasing the brake quick-release and checking pad alignment. Pads should sit perfectly parallel to the rim and be evenly spaced on both sides. If necessary, loosen the pad bolt, adjust the position, and torque it securely.
Next, inspect cable tension. With the lever released, there should be minimal slack, and pads should begin moving with the first portion of lever travel. If the lever feels spongy, use the barrel adjuster to incrementally increase tension until the pads engage smoothly and evenly.
For caliper centering, apply light pressure to the brake lever to engage the pads, then use a 4mm or 5mm hex wrench to fine-tune the centering bolt. Make adjustments until both pads retract equally and sit equidistant from the rim.
Finally, test the setup by spinning the wheel and actuating the lever. There should be no rubbing, and braking should feel immediate and strong.
Compatibility Pitfalls to Watch For
Although the BR-6700 is optimized for road frames designed with short-reach calipers (39–49mm), it may underperform if mounted on incompatible frames. Frames with overly wide or narrow brake mounts can lead to misalignment or compromise the centering mechanism.
Additionally, the brake pads included with the BR-6700 are designed for aluminum rims. If you’re running carbon wheels, you must replace the stock pads with carbon-specific compounds. Failing to do so not only reduces braking efficiency but can severely damage the carbon rim surface.
Performance Optimization Tips
Once correctly set up, the BR-6700 can deliver smooth and powerful braking for years. To keep them performing like new, consider these tips:
- Regularly clean rim braking surfaces with isopropyl alcohol to remove grime and brake residue.
- Replace worn pads early, before the wear indicators disappear.
- Inspect cable housing for signs of compression or contamination—especially near bends.
- Lubricate pivot points lightly with a drop of silicone or PTFE-based lubricant to maintain snappy pad retraction.
- Check caliper mounting bolts for tightness and torque to manufacturer specs periodically.
Conclusion
If your Shimano BR-6700 brakes aren’t delivering the performance they’re known for, improper setup is the likely culprit. By addressing common issues such as cable tension, pad alignment, caliper centering, and rim compatibility, you can restore confidence-inspiring braking performance. With precise adjustments and routine maintenance, these calipers can provide years of reliable use, even in demanding conditions.