Bicycle Cranks Loose

Symptoms: Wobbling or rocking of the crank arms, unusual noises during pedaling.

1. Visual Inspection: Check if the crank bolts are visibly loose.
2. Physical Check: Try to wiggle the crank arms. Any movement suggests that the bolts are not tight enough.
3. Torque Test: Use a torque wrench to check if the crank bolts are tightened to the manufacturer's specified torque. See the Crank Arm Guide.

Symptoms: Side-to-side movement of the crankset, grinding or creaking sounds when pedaling.

1. Physical Inspection: Grasp the crank arms and try to move them side to side, feeling for any play or looseness.
2. Check for Damage: Inspect the bottom bracket for any visible signs of damage or wear.
3. Adjustment Check: If adjustable, ensure the bottom bracket is tightened correctly according to specifications.

Symptoms: Difficulty in keeping the crank arms tight, excessive movement, or slipping.

1. Remove Crank Arms: Carefully remove the crank arms to inspect the square taper.
2. Inspect for Wear: Look for signs of rounding or deformation on the square taper interfaces.
3. Compare and Contrast: If possible, compare with a known good square taper to assess the extent of the wear.

Symptoms: Rough or grinding feeling when rotating the cranks, excessive play in the bottom bracket.

1. Rotation Test: Rotate the crankset and feel for any roughness or grinding, which indicates bearing wear.
2. Play Examination: Check for any play in the bottom bracket by moving the crank arms side to side.
3. Disassembly and Inspection: Disassemble the bottom bracket to inspect the bearings. Look for visible signs of wear, pitting, or corrosion.