Correctly tightening the crank arm bolts on your Shimano FC-4700 [paid link] crankset is essential for smooth and safe riding. Improper tightening can lead to performance issues, including creaking sounds, wobbling, or even damage to the crankset and bottom bracket. This guide will walk you through the precise procedure to ensure the crank arm bolts on your Shimano FC-4700 [paid link] are tightened to the correct specifications for optimal performance.

Tools Required

• 8mm Allen wrench [paid link] or torque wrench [paid link] with 8mm hex socket
• Torque wrench [paid link] (optional, for precise tightening)
• Grease or anti-seize compound (optional)

Understanding the Shimano FC-4700 Crankset

The Shimano FC-4700 [paid link] crankset is part of Shimano’s 4700 series, designed for road bikes and providing excellent power transfer and smooth shifting. Ensuring the crank arm bolts are tightened correctly is crucial for maintaining the performance and longevity of the crankset. The FC-4700 features a 4-arm design with a direct mount, making the crank arm bolt positioning and tightening procedure slightly different from other cranksets.

Importance of Proper Crank Arm Bolt Tightening

Tightening the crank arm bolts properly ensures that the crank arms stay securely attached to the bottom bracket axle. If the bolts are too loose, the crank arms may shift or wobble during pedaling, resulting in poor power transfer and an uncomfortable ride. On the other hand, over-tightening the bolts can strip the threads in the crankset, leading to permanent damage.

Step-by-Step Guide to Tightening the FC-4700 Crank Arm Bolts

Step 1: Inspect the Crankset and Bolts

Before tightening the bolts, make sure that both the crank arms and bolts are in good condition. Check for any visible damage or wear. Also, inspect the crank arm interface for dirt or debris. Clean the area thoroughly to prevent contaminants from causing issues with tightening.

Step 2: Apply Lubricant (Optional)

It is recommended to apply a small amount of grease or anti-seize compound to the threads of the crank arm bolts. This helps to prevent rusting and makes future maintenance easier. However, avoid excessive lubrication, as too much grease can lead to slippage.

Step 3: Align the Crank Arm

Ensure the crank arm is properly aligned on the bottom bracket axle. For the Shimano FC-4700, the crank arm should be positioned correctly with the pedal threads facing forward (on the non-drive side) and the chainring on the drive side.

Step 4: Insert the Crank Arm Bolt

Place the crank arm bolt into its corresponding hole and ensure it is seated properly. The bolt should go into the crank arm and thread into the axle interface smoothly. Do not force it; if it feels resistant, remove the bolt, clean the threads, and inspect for debris.

Step 5: Tighten the Bolt to the Correct Torque Specification

Using an 8mm Allen wrench [paid link] or a torque wrench [paid link] with an 8mm hex socket, begin tightening the crank arm bolt. The recommended torque setting for the Shimano FC-4700 crank arm bolt is 12–14 Nm (Newton-meters).

• If using a torque wrench: Set it to 12–14 Nm and tighten the bolt slowly. This ensures you achieve the correct tightness without over-tightening.
• If using an Allen wrench [paid link]: Tighten the bolt firmly, but do not use excessive force. Aim for a snug, secure fit without over-stretching the crank arm.

Step 6: Check for Proper Tightness

After tightening the bolt, give the crank arm a gentle wiggle. There should be no visible movement or play between the crank arm and the bottom bracket axle. If the crank arm feels loose, repeat the tightening process, ensuring that you are within the correct torque range.

Common Issues with Crank Arm Bolt Tightening

Crank Arm Wobbling or Movement

If the crank arm is still wobbling after tightening, it could be a sign of damaged threads on either the crank arm or the bottom bracket axle. In such cases, replacing the damaged part is recommended to avoid further issues.

Crank Arm Creaking

Creaking noises often indicate loose bolts, dirt in the crank arm interface, or insufficient lubrication. Double-check the bolt tightness and clean the area thoroughly. Applying a light amount of grease or anti-seize compound to the threads can often eliminate creaks.

Stripped Threads

Over-tightening the crank arm bolts can strip the threads in the crankset or bottom bracket axle, leading to a situation where the bolts can no longer hold the crank arm securely. If you suspect stripped threads, you may need to replace the crankset or bottom bracket, depending on the extent of the damage.

Final Thoughts on Crank Arm Bolt Tightening

Correctly tightening the Shimano FC-4700 crank arm bolts is vital for ensuring your bike’s drivetrain works efficiently. By following these precise steps, you can prevent common issues like wobbling, creaking, and damage to the crankset. Remember that using a torque wrench and applying proper lubrication will not only improve the performance of your bike but also extend the lifespan of your crankset and bottom bracket.