How the heck does this come off ?
- Thread starter Gillstay
- Start date
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chriswoody
Legendary Member
- Location
- Northern Germany
A quick google lens search comes up with the fact that there Rotor RCK cranks. More info here:
https://www.torqfitness.co.uk/news/rotor-rck-system-cranks
There's another article here which also mentions how they attach to the bike:
https://autobus.cyclingnews.com/tech/?id=2002/reviews/rotor_cranks
Maybe there's something helpful there? Personally though I've never encountered them before. Good luck and let us know how you get on.
Edit, I've just remembered Google Gemini (AI) and decided to ask it and this is the response I received:
Rotor RCK cranks have a unique design that allows for adjustment of the crank angle during the pedal stroke. While this offers performance benefits, it also means the removal process might be slightly different from standard cranksets.
Here's a general guide on how to remove Rotor RCK cranks, along with the tools you'll likely need. Always refer to the specific instructions provided by Rotor for your exact RCK model if you have them, as there can be subtle variations.
Tools You'll Likely Need:
https://www.torqfitness.co.uk/news/rotor-rck-system-cranks
There's another article here which also mentions how they attach to the bike:
https://autobus.cyclingnews.com/tech/?id=2002/reviews/rotor_cranks
Maybe there's something helpful there? Personally though I've never encountered them before. Good luck and let us know how you get on.
Edit, I've just remembered Google Gemini (AI) and decided to ask it and this is the response I received:
Rotor RCK cranks have a unique design that allows for adjustment of the crank angle during the pedal stroke. While this offers performance benefits, it also means the removal process might be slightly different from standard cranksets.
Here's a general guide on how to remove Rotor RCK cranks, along with the tools you'll likely need. Always refer to the specific instructions provided by Rotor for your exact RCK model if you have them, as there can be subtle variations.
Tools You'll Likely Need:
- 8mm Hex Wrench (Allen Key): Most Rotor cranks are tightened with 8mm bolts.
- Torque Wrench: Crucial for reinstallation to ensure proper tightening and prevent damage.
- Crank Arm Puller (possibly, but many Rotor cranks are self-extracting): If your RCK cranks are not self-extracting, you will need a specific crank puller tool.
- Bottom Bracket Tool (if removing the bottom bracket): If you're removing the entire crankset and bottom bracket, you'll need the correct tool for your specific bottom bracket type (e.g., external bottom bracket tool, Shimano Hollowtech II tool, etc.).
- Grease: For reinstallation.
- Clean Rags/Paper Towels: For cleaning components.
- Prepare Your Workspace:
- Lay out your tools.
- Place a clean rag or paper towels on the floor to catch any small parts or grease.
- Having your bike in a repair stand will make this much easier.
- Identify Self-Extracting Bolt (if applicable):
- Many modern Rotor cranks are designed to be self-extracting. This means the main crank bolt (usually an 8mm hex) works in conjunction with an outer cap or ring. As you loosen the main bolt, it pushes against this outer piece, extracting the crank arm from the spindle.
- Remove the Non-Drive Side (Left) Crank Arm:
- Locate the main crank bolt on the non-drive side crank arm. This is typically an 8mm hex bolt.
- Using your 8mm hex wrench, loosen the bolt.
- If it's a self-extracting crank, continue to turn the bolt counter-clockwise. You will feel resistance as the bolt pushes against the outer cap, and then the crank arm should gradually pull away from the spindle.
- If it's not self-extracting, you will loosen the bolt and then use a crank arm puller tool to remove the crank arm. Follow the instructions for your specific crank puller.
- Remove the Drive Side (Right) Crank Arm and Spindle:
- Once the non-drive side crank arm is removed, the spindle (the axle connecting the two crank arms) should be able to be pulled out from the drive side.
- Carefully slide out the spindle and the drive side crank arm, keeping track of any spacers or dust caps that come off. It's highly recommended to keep them in the order they were removed to ensure correct reinstallation.
- Inspect and Clean:
- Clean the crank arms, spindle, and any spacers or dust caps thoroughly with a degreaser.
- Inspect all components for wear or damage.
- RCK System Specifics: The original Rotor RCK system is unique because the cranks are not fixed at 180 degrees and the chainring rotation axis doesn't coincide with the crank rotation axis. While the core removal of the crank arms will be similar to other cranksets, be aware of this unique design, especially if you plan to reinstall or adjust the chainring. The chainring often attaches to the spindle, not directly to the crank arm on some Rotor models.
- Integrated Bottom Bracket/Crank Arm: Some older Rotor RCK systems had the right crank arm and bottom bracket integrated. If you have this type, the entire unit would be wound into your bottom bracket shell. Removal would involve unscrewing the bottom bracket unit as a whole, using a specific bottom bracket tool.
- Tightening Torque: When reinstalling, always use a torque wrench and tighten the crank bolt to the manufacturer's specified torque. Rotor typically specifies values around 35-40 Nm for their crank bolts. Overtightening or undertightening can lead to damage or premature wear.
- Bearing Adjustment Ring (Non-Drive Side): Some Rotor cranks have an adjustment ring on the non-drive side to fine-tune the bearing preload. This ring is usually secured by a small 2mm hex screw. You will need to loosen this screw before adjusting the ring, and then nip it up again to secure it once the crank is installed and adjusted for no play.
OP
OP
Gillstay
Veteran
Bloomin brilliant. I have found that is got I think a self extractor but its damaged and so I have managed to get it all off from undoing the non drive side as suggested. The bit i did not find is the older version being integrated which this may well be.
I think I will clean and grease every bit I can, as some bits are very tight and if I snap a stud it will ruin it all. Then if I use it a bit and keep penetrating agent on it then I may have a better chance of dismantling it all later. many thanks. much appreciated. Will post photo's.
