Splined Crank Removal and Replacement
This type of crank attachment is found on many high-performance mountain bikes.
Instead of a square hole that fits over the tapered spindle, the crank has slots
around a round opening. The slots fit onto teeth that stick out from a hollow
round spindle in the bottom bracket. This setup is easier to remove than the
tapered spindle type, requiring only a hex wrench. (You don't need a special
crank-pulling tool. If the crank won't come off after removing the cap bolt, you
may have a tapered splined spindle, which DOES require a crank-pulling tool.) Other crank types: standard
female-threaded tapered spindle, male-threaded spindle
with nut, tapered splined spindle.
|Insert a hex-head wrench into the opening at the base of the
crank. You use the same tool you'd use to remove the dust-cap screw from
the crank on a standard tapered-spindle bottom bracket. Turn
counter-clockwise until the bolt and dust-cap are loose. (The dust cap may
keep the bolt from coming completely out of the crank -- you don't need to
pull it out, you only need to loosen it.)
||If you're working on the chainring side, take the chain off
the rings and hang it on the outside of the bottom bracket. Slide the
crank out away from the bottom bracket.
If you removed the crank to replace chainrings,
do that now.
Inspect the spindle for damage, and check for side-to-side
(left-to-right) motion of the spindle in the bottom bracket. Listen for grinding or rubbing as you turn the spindle. If the bottom
bracket is bad, now's a good time to replace it.
|If you're replacing the cranks (not simply removing it to
replace a chain ring), place the new crank -- in the same position on the spindle as the old
one. Apply Loctite to
the threads of the retaining bolt and tighten it.
If you're replacing the crankset, you're now ready to thread the pedal into the
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