Cranks Spare Parts

What can I find here and why do I need it?

Even the strongest crank needs maintenance. Here are the necessary individual parts to save a defective crank instead of buying a completely new one. Most common parts are bolts and the spindle.

The Anatomy of Crank Spare Parts

Spindle

The connecting rod between the two crank arms. It must exactly match the inner diameter of the bottom bracket.

Spindle Bolts

The side bolts that pull the crank arm onto the spindle.

Wedge

Specific for clamping systems like on Primo Powerbite/Hollowbite cranks.

Which dimensions and standards do I need to watch out for?

"Wild guessing" does not work here. You need to know three values:

• Spindle Diameter:
  • 19mm: Classic standard (e.g., Profile, many entry-level cranks).
  • 22mm: Very common for maximum stability (e.g., Odyssey, Eclat, BSD).
  • 24mm: Newer standard for extreme stiffness.
• Splines:
  • 48 Spline: The fine-toothed standard mount for BMX.
  • 8 Spline: Coarse teeth on cheaper cranks.
• Thread (Bolts): Profile Racing uses e.g., Imperial threads, almost everyone else uses Metric (M10, M12, M14, M15).

How do I fix common problems?

• Crank arm wobbles: Check if the side bolt is loose. If it is tight and the arm still wobbles, the splines are often worn out -> New spindle or new arm needed.
• Creaking noises: Clean the spindle and regrease it. Dry metal on metal causes noise.

What do the specifications mean?