Every cyclist eventually encounters the need to remove their bicycle crank, whether it’s for maintenance, repair, or upgrading. While it may seem like a daunting task, the process is relatively straightforward with the right tools and knowledge. This comprehensive guide will walk you through the steps involved in safely and effectively removing your bicycle crank, empowering you to tackle this essential maintenance task with confidence.
To begin the crank removal process, gather the necessary tools: a crank puller, a 5mm Allen key, and a chain whip. The crank puller is a specialized tool designed to extract the crank from the bottom bracket spindle. The Allen key is used to loosen the crank bolts, while the chain whip prevents the crank from spinning as you apply force with the crank puller. With your tools in hand, you’re ready to embark on the crank removal procedure.
Before applying significant force, ensure that the crank bolts are loosened but not yet fully removed. Using the Allen key, carefully unscrew each crank bolt about halfway. This will allow the crank puller to engage with the spindle without the risk of damaging the threads. Once the bolts are loosened, attach the crank puller to the spindle and secure it according to the manufacturer’s instructions. With the crank puller in place, slowly tighten the puller bolt, applying steady pressure until the crank releases from the spindle. Once the crank is loose, carefully remove the crank puller and set the crank aside for further maintenance or replacement.
Identifying the Crank Type
Before delving into the intricacies of crank removal, it is imperative to correctly identify the type of crank you are working with. Different crank designs necessitate different removal methods. Here’s a comprehensive guide to help you determine your crank type:
Cottered Cranks
Cottered cranks are characterized by a cotter pin that secures the crank arm to the spindle. To identify this type, look for a small hole on the inside of the crank arm, where the cotter pin is inserted. Cotter cranks are commonly found on older bicycles, particularly classic road and track bikes.
Square Taper Cranks
Square taper cranks feature a square-shaped spindle that fits into a corresponding square hole in the crank arm. This design is prevalent in many modern bicycles, offering a secure and reliable connection between the crank and the spindle. To identify square taper cranks, simply examine the end of the spindle, which will have a square profile.
Octalink Cranks
Octalink cranks utilize a proprietary Shimano spline interface between the crank arm and the spindle. They are typically identified by eight splines on the spindle and eight corresponding grooves on the crank arm. Octalink cranks are predominantly found on higher-end bicycles and provide excellent stiffness and durability.
ISIS Cranks
ISIS cranks, developed by Truvativ, employ a similar spline interface to Octalink. However, the splines on ISIS cranks are slightly larger and the crank arms typically have a narrower profile. They are commonly used on mid-range and high-performance bicycles.
| Crank Type | Identifying Feature | Location |
|---|---|---|
| Cottered | Cotter pin hole | Inside of crank arm |
| Square Taper | Square-shaped spindle | End of spindle |
| Octalink | Eight splines on spindle, eight grooves on crank arm | Spindle and crank arm |
| ISIS | Larger splines, narrower crank arms | Spindle and crank arm |
Gathering Necessary Tools
Before embarking on the task of removing a bicycle crank, it’s crucial to gather the appropriate tools to ensure a smooth and efficient process. Here’s a comprehensive list of the essential tools you’ll need:
1. Crank Extractor
A crank extractor is a specialized tool designed to remove the crank arms from the spindle. This tool typically consists of a long bolt and a puller that attaches to the crank arm and applies force to extract it. It’s important to select a crank extractor compatible with your specific crank system, as different systems may require different extractors.
2. Allen Wrenches
Allen wrenches, also known as hex keys, are indispensable for loosening and tightening bolts. In the context of crank removal, you’ll likely encounter Allen bolts that secure the crank arms to the spindle. A set of Allen wrenches with various sizes will ensure you have the right tool for the job. Here’s a table summarizing the typical sizes needed for crank removal:
| Removable crank | Allen wrench size |
|---|---|
| Shimano | 8mm |
| SRAM | 10mm |
| Campagnolo | 12mm |
3. Socket Wrench and Sockets
A socket wrench with an appropriate socket is typically required to remove the preload bolt that secures the crankset to the bottom bracket. The specific socket size will depend on the type of crankset you have. Refer to the manufacturer’s specifications or documentation to determine the correct socket size.
Removing the Lockring
The lockring is a large, ring-shaped component that holds the crank in place. To remove it, you’ll need a chain whip and a lockring tool.
1. Secure the bike in a stand or on the ground.
2. Use the chain whip to hold the crank in place.
3. Insert the lockring tool into the slots on the lockring. Turn the tool counterclockwise to loosen the lockring. The lockring may be very tight, so you may need to use a cheater bar to provide extra leverage.
4. Once the lockring is loose, remove it by hand.
Here are some additional tips for removing a lockring:
• If you don’t have a chain whip, you can use an old chain to wrap around the cassette and hold the crank in place.
• If you don’t have a lockring tool, you can use a large flat-head screwdriver or a pair of pliers to loosen the lockring.
• If the lockring is too tight to remove by hand, you can use a cheater bar to provide extra leverage.
• Be careful not to damage the lockring or the crank when removing it.
Detaching the Crankarms
To remove the crank arms from the bottom bracket spindle, you will need a crank puller. This is a specialized tool that provides sufficient leverage to break the taper-lock connection between the crank arm and the spindle.
There are two main types of crank pullers: single-pull and double-pull. Single-pull crank pullers are less expensive and easier to use, but they may not be powerful enough to remove all crank arms. Double-pull crank pullers are more powerful, but they are also more expensive and difficult to use.
To use a crank puller, follow these steps:
- Select the correct size crank puller bolt for the crank arm you are removing.
- Insert the bolt into the crank arm and tighten it until it is snug.
- Attach the crank puller to the bolt and tighten the puller’s locking screw.
- Slowly turn the puller’s handle until the crank arm pops off the spindle. Be careful to avoid excessive force, as this can damage the crank arm or the spindle.
| Type of Crank Puller | Description |
|---|---|
| Single-pull | Less expensive and easier to use, but may not be powerful enough to remove all crank arms. |
| Double-pull | More powerful, but also more expensive and difficult to use. |
Disassembling the Bottom Bracket
1. Remove the crank arms
Using a 5mm hex key, loosen the pinch bolts on both crank arms. Then, use a crank puller to remove the crank arms from the bottom bracket spindle.
2. Remove the bottom bracket cups
If your bottom bracket has external cups, you can use a bottom bracket tool to remove them. If your bottom bracket has internal cups, you will need to use a special tool called a bottom bracket extractor.
3. Remove the bottom bracket spindle
Once the cups are removed, you can remove the bottom bracket spindle. The spindle is held in place by a retaining ring. Use a pair of pliers to remove the retaining ring, and then pull the spindle out of the frame.
4. Clean the bottom bracket components
Once the bottom bracket is disassembled, you should clean all of the components thoroughly. Use a degreaser to remove any grease or dirt, and then wipe down the components with a clean rag.
5. Inspect the bottom bracket components
Once the components are clean, inspect them for any damage. If you find any damage, you will need to replace the damaged components.
| Component | Damage to look for |
|---|---|
| Crank arms | Bends, cracks, or other damage |
| Bottom bracket cups | Cracks, broken threads, or other damage |
| Bottom bracket spindle | Bends, broken threads, or other damage |
| Retaining ring | Deformation or damage |
Replacing the Bottom Bracket (Optional)
Before you begin removing the crank, it’s important to consider whether you also need to replace the bottom bracket. Symptoms of a bad bottom bracket include grinding noises, difficulty pedaling, and excessive play in the cranks. If you’re experiencing any of these issues, it’s best to replace the bottom bracket at the same time as the crank.
To replace the bottom bracket, you’ll need a bottom bracket tool. The type of tool you need will depend on the type of bottom bracket you have. Once you have the right tool, simply follow these steps:
1. Remove the crank bolts.
2. Use the bottom bracket tool to loosen the bottom bracket cups.
3. Remove the old bottom bracket and install the new one.
4. Tighten the bottom bracket cups using the bottom bracket tool.
5. Install the crank bolts and tighten them to the specified torque.
6.
Checking for Crank Arm Play
Once you’ve reassembled the crankset, it’s important to check for crank arm play. This is a common problem that can cause noise and premature wear on the bottom bracket. To check for crank arm play, simply grab the crank arm and try to move it side-to-side. There should be no play in the crank arm. If there is, it means that the bottom bracket is not properly adjusted. You can adjust the bottom bracket by tightening the bottom bracket cups until the play is eliminated.
| Symptom | Possible Cause |
|---|---|
| Grinding noise when pedaling | Bad bottom bracket |
| Difficulty pedaling | Bad bottom bracket |
| Excessive play in the cranks | Bad bottom bracket |
Reattaching the Crank Arms
Now that the crank arms have been removed, it’s time to reattach them. This process is relatively simple, but there are a few things to keep in mind.
First, make sure that the crank arms are properly aligned. The left crank arm should be installed first, and it should be aligned with the left pedal spindle. The right crank arm should then be installed, and it should be aligned with the right pedal spindle.
Once the crank arms are aligned, they can be tightened into place. The left crank arm should be tightened first, and it should be tightened to the recommended torque using a torque wrench. The right crank arm should then be tightened, and it should also be tightened to the recommended torque.
The crank arms should now be properly installed and tightened. You can now reattach the pedals and begin riding your bike.
Here is a table summarizing the steps involved in reattaching the crank arms:
| Step |
|---|
| Align the left crank arm with the left pedal spindle and install it. |
| Align the right crank arm with the right pedal spindle and install it. |
| Tighten the left crank arm to the recommended torque using a torque wrench. |
| Tighten the right crank arm to the recommended torque. |
| Reattach the pedals and begin riding. |
Installing the Lockring
The lockring is a thin, metal ring that threads onto the cassette body and holds the cassette in place. To install the lockring, you will need a lockring tool. You can purchase a lockring tool at most bike shops or online.
Here are the steps to install the lockring:
- Place the lockring on the cassette body.
- Thread the lockring tool onto the cassette body.
- Turn the lockring tool clockwise to tighten the lockring.
- Tighten the lockring until it is snug.
- Remove the lockring tool.
- Check the lockring to make sure it is tight.
Here are some additional tips for installing the lockring:
- Use a lockring tool that is the correct size for the lockring.
- Do not overtighten the lockring.
- If the lockring is too tight, it can damage the cassette body.
- If the lockring is too loose, the cassette can come loose and fall off the bike.
Here is a table that summarizes the steps for installing the lockring:
| Step | Action |
|---|---|
| 1 | Place the lockring on the cassette body. |
| 2 | Thread the lockring tool onto the cassette body. |
| 3 | Turn the lockring tool clockwise to tighten the lockring. |
| 4 | Tighten the lockring until it is snug. |
| 5 | Remove the lockring tool. |
| 6 | Check the lockring to make sure it is tight. |
Tightening and Aligning the Cranks
Once you have removed the crank arms, you need to tighten them back onto the spindle. This is important to ensure that the cranks are properly aligned and that they do not come loose while you are riding.
To tighten the cranks, you will need to use a torque wrench. A torque wrench is a tool that measures the amount of torque that is applied to a bolt or nut. This ensures that the bolt or nut is tightened to the correct specification.
The torque specification for crank bolts will vary depending on the manufacturer of the crankset. However, most crank bolts will need to be tightened to between 25 and 35 Nm.
Once you have tightened the crank bolts, you need to align the cranks. To do this, you will need to use a chain checker or a ruler.
A chain checker is a tool that measures the distance between the chainrings. A ruler can also be used to measure the distance between the chainrings, but it is not as accurate as a chain checker.
The distance between the chainrings should be equal to the width of the chain. If the distance between the chainrings is too narrow, the chain will be too tight and will wear out prematurely.
If the distance between the chainrings is too wide, the chain will be too loose and will skip gears.
Once you have aligned the cranks, you can install the chain.
Checking for Crank Tightness
It is important to periodically check the tightness of your crank bolts. This is especially important if you have recently installed a new crankset or if you have been riding in rough conditions.
To check the tightness of your crank bolts, you will need to use a torque wrench.
| Crank Bolt Torque |
|---|
| 25-35 Nm |
If the crank bolts are not tightened to the correct specification, they could come loose while you are riding. This could cause the cranks to fall off, which could lead to a serious accident.
Troubleshooting
If you are having difficulty removing the crank, there are a few troubleshooting tips you can try:
- Make sure the crank bolts are loosened. The crank bolts are located on the inside of the crank arms, and they need to be loosened before the crank can be removed.
- Use a longer wrench. If you are using a short wrench, you may not be able to get enough leverage to loosen the crank bolts.
- Apply some penetrating oil. If the crank bolts are rusted or seized, you can apply some penetrating oil to help loosen them.
- Tap the crank arm with a hammer. This can help to loosen the crank bolts and make them easier to remove.
- Remove the chainring. If the chainring is preventing you from removing the crank, you can remove it using a chainring bolt wrench.
Maintenance
Once you have removed the crank, it is important to clean and lubricate it before reassembling it. This will help to prolong the life of the crank and keep it running smoothly.
- Clean the crank. Use a rag or brush to clean the crank, removing any dirt or debris.
- Lubricate the crank. Apply a thin layer of grease to the threads of the crank bolts and to the inside of the crank arms.
- Reassemble the crank. Tighten the crank bolts to the specified torque, and then reattach the chainring.
| Crank Type | Torque |
|---|---|
| Square Taper | 40-50 Nm |
| Octalink | 50-60 Nm |
| ISIS | 60-70 Nm |
| Hollowtech II | 80-90 Nm |
How to Remove a Bicycle Crank
Removing a bicycle crank is a relatively simple task that can be performed with a few basic tools. Here are the steps on how to do it:
- Gather your tools. You will need a crank puller, a 5mm Allen key, and a chain whip.
- Remove the pedals. Use a 15mm spanner to loosen the pedals and then remove them by hand.
- Remove the chainring bolts. Use a 5mm Allen key to loosen the chainring bolts and then remove them by hand.
- Attach the crank puller to the crank. There are two different types of crank pullers: one for square taper cranks and one for splined cranks. Make sure you are using the correct type of crank puller for your crank.
- Tighten the crank puller. Use a 5mm Allen key to tighten the crank puller until the crank starts to move.
- Remove the crank. Once the crank has started to move, you can remove it by hand.
People Also Ask
How do I know if my crank needs to be replaced?
There are a few signs that your crank may need to be replaced:
- If the crank is bent or cracked, it should be replaced immediately.
- If the crank is loose or wobbly, it may need to be replaced.
- If the crank is making noise, it may need to be replaced.
