The cranks on your bike are levers that connect your bottom bracket spindle and the pedals. They have toothed sprockets referred to as chainrings. You might need to remove your cranks in order to replace them or the chainrings, service the bottom bracket and clean chainrings. There are different types, and each of them has a specific way to remove and install them.
If you don’t know how to identify the type you use, then read on.
This type has the crank puller built into it. They make use of threaded rings which resemble dust caps. These rings are threaded on the bolt. What this means is that when you loosen the bolt, its shoulder presses against the ring. It ultimately pushes apart the spindle and the arm. With this system, you don’t need any other crank removal tool. Self-Extracting systems are either two piece or three-piece.
You can usually find this on Shimano and FSA cranksets. They have a left arm fitted with a compression slot that is in turn held in place by two pinch bolts along with a right arm and integrated spindle. You don’t need to use conventional pullers for this system because it uses external bearing cups.
Campagnolo Power Torque has a spindle fitted on the drive side. You need to remove the left or right side in order to access the bearings.
Campagnolo Ultra Torque is popular with Campagnolo and Fulcrum. The spindle is fitted on the right and left arms. There are also teeth fitted on the spindle ends. Although this classification makes use of external bearing cups, they aren’t integrated. Rather, they are fixated on the cranks.
The left side cup usually has a wavy washer. It works as a bearing adjustment while also accounting for frame shell width variation.
This has three parts: the left and right arms, and the spindle. Frame bearings hold the spindle in position. You need to remove both in order to replace or service the bearings. The left and right arms also have bolts.
Generally, three pieces have two types of interfaces: splined spindle arms or square spindle arms.
There is also a unique three piece system for BMX and freestyle bicycles. A lot of them use systems with a 48 spline spindle. The difference between this and other three piece systems is the procedure for servicing them.
You are likely to find this on older Schwinn bikes, BMX bikes, children’s bikes, and department store-type bikes. The crank arms are formed by a single piece of steel. It goes from one pedal, passes in between the bottom bracket, and connects with the other pedal. It also serves as the bearing axle for the bottom bracket.
Although there are different types of classifications, you can remove and install them when you use Shimano crank tools. With these tools, you get a collection of a broad range of tools for the different types.