Introduction to Shimano Cranks
Shimano cranks are a crucial component of most modern bicycles. They transfer power from the pedals to the drivetrain, propelling the bike forward. Proper maintenance and removal of Shimano cranks is an important skill for any cyclist to master. In this guide, we’ll walk through the process of removing Shimano cranks step-by-step.
What are Shimano Cranks?
Shimano cranks are the arms that connect the pedals to the bottom bracket of the bike. They are typically made of aluminum alloy for strength and lightweight. The crankset consists of the cranks, chainrings, and the bottom bracket axle that the cranks attach to.
Types of Shimano Cranks
There are several types of Shimano cranks, but the most common on modern bikes are Hollowtech II cranks. These two-piece cranks feature a splined interface between the drive-side crank and the bottom bracket spindle. This allows for easy removal and installation without having to remove the bottom bracket cups.
Other types include Octalink and square taper cranks which are an older design that require removal of the bottom bracket to service the cranks.
Tools Required for Removing Shimano Crank
Before getting started, make sure you have the necessary tools on hand. Having the right tools will make the job much easier and help prevent damage to the components.
Essential Tools
At a minimum, you’ll need:
- Hex wrench set – Used to loosen the crank arm pinch bolts. Sizes needed are usually 5mm and 6mm.
- Adjusting cap tool – A splined tool used to remove the drive-side crank arm cap.
- Torque wrench – For proper reinstallation, a torque wrench ensures the pinch bolts are tightened to spec, usually 12-14 Nm.
Optional Tools
A few additional tools can make the job easier in some cases:
- Rubber mallet or dead blow hammer – Used to tap the crank arm to break it free if needed.
- Pick or awl – Helpful for removing rubber seals or o-rings.
- Grease and thread locker – For the installation process, grease the splines and threads, blue threadlocker on the pinch bolts.
Step-by-Step Guide to Removing Shimano Crank
Now that you have your tools ready, follow these steps to remove your Shimano crankset. The process is similar for most Hollowtech II cranks.
Step 1: Loosen the Pinch Bolts
Start by loosening the two pinch bolts on the non-drive side crank arm using your 5mm hex wrench. These bolts clamp the left crank arm onto the spindle. Turn counterclockwise to loosen. Remove the bolts and set aside.
Step 2: Remove the Crank Cap
On the drive side, locate the splined crank cap. This plastic cap covers the attachment point for the drive side crank. Use your adjusting cap tool and turn counterclockwise to remove it.
If the cap is stuck, gently tap the top with a mallet to break it free. Be careful not to damage the threads.
Step 3: Pull the Left Crank Arm
With the bolts and cap removed, the left crank arm should slide off the spindle. If it’s stuck, use a rubber mallet to tap it from behind to push it off the spindle.
Don’t use a metal hammer as this can damage the crank. Work the crank arm off gently.
Step 4: Remove the Right Crank Arm
With the left arm off, the drive-side crank will easily pull off the bottom bracket spindle. You may need to use your hands to wiggle it as you pull it away from the bike. The spindle is splined which allows the right arm to simply pull off.
Reinstalling Shimano Crank
Reinstalling the crankset is essentially the reverse of removal, with a few important things to keep in mind. Take your time and make sure everything is clean and properly lubricated.
Step 1: Grease the Spindle
Before reinstalling, apply a thin layer of grease to the splines of the bottom bracket spindle. This will help prevent any creaking and make future removal easier. Be sure to wipe away any excess or dirt first.
A little grease goes a long way – don’t overdo it or you’ll attract more dirt.
Step 2: Position the Crank Arms
Slide the drive-side crank onto the spindle and set into position. Make sure the splines engage and the crank sits flush against the bottom bracket.
Next position the non-drive crank onto the spindle. Again make sure it slides on fully and sits flush against the spindle shoulder. The two pinch bolt holes should line up with the matching holes on the spindle.
Step 3: Tighten the Pinch Bolts
Apply a small amount of thread locker to the pinch bolts and thread them into the non-drive crank arm. Using your torque wrench, tighten the bolts to the manufacturer’s recommended torque, usually 12-14 Nm.
Over-tightening the bolts can damage the crank or cause binding, so a torque wrench is highly recommended. Tighten both bolts evenly in an alternating pattern.
Finally, thread the plastic crank cap into the drive-side crank and hand tighten with the adjusting cap tool.
Common Tips and Warnings
Here are a few extra tips to keep in mind when servicing Shimano cranks, as well as some important warnings.
Tips for Smooth Removal and Installation
- Remove the chain from the chainrings before starting, this will give you more room to work.
- If your bike has them, remove the pedals from the cranks first, this makes it easier to grip and rotate the cranks.
- After reinstalling, check that there is no side-to-side play in the cranks, if so, you may need to regrease and retighten.
Warnings to Avoid Damage
- Never use an adjustable wrench or pliers on the crank bolts, only use hex wrenches that fully engage the bolt head.
- Over-tightening the pinch bolts can damage the crank arms or cause binding and poor performance.
- Regularly check the bolts for loosening, as riding with a loose crank can damage the splines.
Conclusion
Removing and installing Shimano cranks is a straightforward process that most home mechanics can do with the right tools and a bit of patience.
Summary of Key Steps
Remember, the key steps in removal are:
- Loosen the pinch bolts
- Remove the crank cap
- Pull the left crank arm off
- Slide the drive-side arm off the spindle
And for reinstallation:
- Grease the spindle
- Position the arms
- Torque the pinch bolts to spec
Final Thoughts
Regular servicing of your cranks will extend their life and keep your bike running smoothly. With the techniques outlined here, you’ll be able to confidently remove and install your Shimano cranks whenever they need maintenance.
Remember to work carefully, keep parts organized, and don’t force anything. If you get stuck, consult Shimano’s official documentation or take your bike to your local shop.
Enjoy the ride!
