Removing and installing ISIS Drive® and Shimano® pipe billet spindle
Level of Difficulty: Novice
Typical tools & supplies 
- Wrench for crank bolt, typically 8mm. Some models may require 10mm.
- Crank Remover
This article will discuss the removal and installation of crankarms on
the round, splined type spindles. These are the ISIS Drive® or Shimano®
Octalink types. For service of square-tapered type crankarms, see Square
Tapered Spindle Type crankarms. See also Crank
The oversized pipe billet splined spindles are round at the ends rather
than square shaped. A series of internal splines in the crank are mated
to external splines on the spindle. The cranks are held tightly to the
spindle by tension from the crank bolt. Shimano® uses an 8-spline design
called Octalink®. A different and non-interchangeable standard is the
ISIS DRIVE® (International Spline Interface Standard). The ISIS DRIVE®
system uses ten splines of a different shape from Shimano®. Again, the
two systems do not interchange.
For all types of crankarms, the first step of removal is to turn the
crank bolt counter-clockwise. Two things might happen. First, the bolt
may simply come out. In this case, inspect inside the crankarm for the
end of the spindle. Remove any washer seen inside. A square hole in the
crankarm uses the square type spindle. In this case see Square
Spindle-Type Crankarms. A round hole in the crankarm where it meets
the spindle is the pipe billet type.
second possibility is the crankarm bolt presses back against a crankarm
cap, or retaining ring, and the entire arm is pulled off. This is the
case if the arm uses a One-Key-Release system. One-key-release
systems use a metal cap threaded into the crankarm. This metal cap takes
the place of the dust cap and surrounds the crankarm bolt head. To remove
the crankarm, leave the ring in place. Turn the crankarm bolt counter-clockwise
and the bolt backs against the ring pulling the arm from the spindle.
Both oversized pipe billet spindle and square type spindle system may
come with the one-key-release system, and both are removed the same way.
It can occur that the one-key-release cap or retaining ring comes loose.
To secure the ring use the Park Tool SPA-2
pin spanner. No crank extractor is required for the one-key-release system,
as seen below.
For oversized pipe billet crankarms not using the one-key-release system,
such as some ISIS Drive® and some Shimano® systems, use Park Tool CWP-6,
Crankarm removal - non-One-Key-Release type
1 Remove crankarm bolt and any washer inside the arm.
2 Unthread nut from handle stud of CCP-4
or CWP-6 until
the tip is flush with the nut. This allows tool to have full thread contact
inside the crank.
3 Thread nut into crankarm and tighten with wrench until snug.
If nut is not completely threaded into crankarm, the threads of the arm
or nut may be damaged.
4 Thread handle stud into nut. When resistance is felt, continue
threading handle stud into nut until crankarm is removed.
5 Repeat process on other arm.
Keep the raised spline aligned
at the top 12:00 position.
Use care when installing the crankarm to the spindle so splines match
correctly. Crankarms using the one-key-release system make it difficult
to see how the arm is fitting to the spindle. A forced mismatch on the
splines can damage the arm. Splined type crankarms without the one-key
system allow easy viewing of the spline fit. The spline pattern on the
spindle consists of a series raised splines separated by flutes or recesses,
at the minor diameter.
1 Grease threads inside bottom bracket spindle. Grease splines
2 Rotate pipe billet spindle so one spline aligns to top dead center,
at the 12:00 position.
3 Position right crankarm on to spindle so arm points straight
down at the 6:00 position. Place crankarm on spindle and carefully thread
bolt into spindle. View opposite side of spindle and check that a narrow
spline is aligned to top dead center. Threading should continue without
resistance until crankarm visually covers spindle splines.
4 Tighten bolt fully. If possible use a torque wrench and secure
to 305-391 inch-pounds.
5 Align left arm so it points directly opposite from right arm.
Thread bolt into spindle and tighten fully.