The Shimano SM-BB5700 [paid link] Hollowtech II bottom bracket is a staple in many road bike drivetrains, offering reliable performance and smooth crank operation. However, improper installation can significantly compromise its functionality, leading to premature wear, creaking noises, and drivetrain inefficiency. This guide walks you through the most common installation mistakes with the SM-BB5700 [paid link]—and how to avoid them for a perfect set-up.
Incorrect Frame Preparation Before Installation
One of the most overlooked but vital steps in installing the SM-BB5700 [paid link] is proper frame preparation. The SM-BB5700 is designed for standard BSA (British Standard Thread) 68mm or 70mm threaded bottom bracket shells. Failing to clean, inspect, and prep this interface can create numerous issues.
Even a small amount of paint, debris, or metal burrs inside the threads can cause misalignment or cross-threading during installation. Threads should be meticulously cleaned using a degreaser, chased with a bottom bracket tap if needed, and lightly greased before threading in the cups. Any failure here can affect bearing alignment and torque accuracy, leading to long-term damage or noise.
Over-Tightening the Bottom Bracket Cups
While it’s essential to secure the cups firmly, over-tightening them is a surprisingly frequent mistake. The SM-BB5700 uses alloy cups, which are softer than steel threads and prone to damage if excessive torque is applied. Shimano specifies a torque range of 35–50 Nm for the cups.
Exceeding this torque can distort the cup threads, compromise the bearing preload, or damage the shell threads in the frame. Moreover, over-tightening doesn’t improve sealing or bearing performance—it merely accelerates wear and makes future removal more difficult.
Use a calibrated torque wrench [paid link] with the correct Hollowtech II bottom bracket tool [paid link] to ensure even and accurate torque during installation.
Skipping or Misplacing the Right Spacers
The SM-BB5700 comes with specific plastic spacers designed to accommodate various shell widths and crankset standards. Using incorrect spacers, placing them in the wrong order, or omitting them entirely can offset the crankarm chainline, cause bearing side-load, or lead to premature wear.
For example, a standard 68mm BSA shell generally requires:
- Two spacers on the drive side
- One spacer on the non-drive side
If your crankset has an integrated chainline correction, these may vary slightly, but the rule remains: follow the Shimano technical manual precisely. Incorrect spacer use results in misaligned crankarms, uneven bearing loading, and undesirable drivetrain behavior.
Neglecting Proper Grease Application
Lubrication plays a critical role in preventing corrosion and facilitating smooth assembly. However, many installers either skip it or use the wrong type of grease on the threads and cup interfaces.
Shimano recommends applying anti-seize or high-pressure waterproof grease to:
- The frame threads
- The spindle surfaces that contact the crank arms
- The contact area between the cups and the shell
Without adequate grease, the SM-BB5700 is more susceptible to galvanic corrosion, especially in wet environments or when mated with carbon frames. Conversely, using low-quality or excessive grease can attract debris, compromising the seal and bearing integrity.
Improper Cup Orientation
Another easily overlooked error is installing the bottom bracket cups in the wrong orientation. The SM-BB5700 has a left-hand thread on the drive side and a standard right-hand thread on the non-drive side. Confusing the sides or tightening them in the wrong direction can strip threads or crack the cup body.
Always double-check markings on each cup:
- “R” (Right/Drive Side) – Left-hand thread
- “L” (Left/Non-Drive Side) – Right-hand thread
Align the cups accordingly and thread them in by hand first before final torquing. This simple check prevents costly damage and ensures correct engagement with the frame.
Failing to Check Bearing Smoothness Post-Installation
Once the SM-BB5700 is installed, it’s crucial to verify that the bearings rotate smoothly with the crankset installed. If there’s noticeable resistance, grinding, or misalignment, something likely went wrong during assembly—such as over-torquing, incorrect spacers, or bearing preload issues.
Riding with excessive drag not only saps pedaling efficiency but can permanently damage the bearings. If you detect any binding or creaking, disassemble the unit immediately, inspect the components, and reassemble with careful attention to Shimano’s guidelines.
Conclusion
Avoiding these common installation mistakes with the Shimano SM-BB5700 bottom bracket can save you from drivetrain inefficiencies, bearing failure, and noisy rides. Accurate torque, correct spacer placement, and thorough preparation are not just recommendations—they’re critical for optimal performance. By understanding and avoiding these pitfalls, you ensure that your SM-BB5700 provides the smooth, durable operation it was designed for.