What is the name for the small hex bolt that attaches the crank to the spindle? Mine managed to fall off my Cannondale Killer V900 last night and I cannibalised one from a different bike and I need to buy a replacement.
Its a bolt. Specifically a square taper crank bolt
davidmcw on
Great, thanks, just bought some
nowhere3 on
If the bolt fell off and the arm fell off then just getting a new bolt almost certainly won’t solve your problem. Once the arm has fallen off it damages the square inside the arm which means that even if you get a new bolt and tighten it, the arm will slowly walk itself off again.
Unlikely-Office-7566 on
If your square taper crank fell off it almost certainly damaged. They are a tolerance fit, when they fall off from coming loose they almost always mushroom the interface on the crank side and continue to have issues.
7 Comments
Crank bolt?
crankarm fixing bolt
crank bolt
square taper crankset bolt
Crank arm bolt/crank bolt
Its a bolt. Specifically a square taper crank bolt
Great, thanks, just bought some
If the bolt fell off and the arm fell off then just getting a new bolt almost certainly won’t solve your problem. Once the arm has fallen off it damages the square inside the arm which means that even if you get a new bolt and tighten it, the arm will slowly walk itself off again.
If your square taper crank fell off it almost certainly damaged. They are a tolerance fit, when they fall off from coming loose they almost always mushroom the interface on the crank side and continue to have issues.