How To Change Your Chainrings and Cranks - GCN's Bike Maintenance Series, by Global Cycling Network on YouTube. 2 min 18 s.
- Video length
- 2 min 18 s
- Time to do it
- 30 minutes
- Difficulty
- Medium
- Steps
- 10
What you need
Steps
Shift the chain onto the smallest chainring and smallest rear cog. This slackens the chain and makes the crank easier to remove.
Loosen the two pinch bolts on the left crank arm with a 5 mm hex key. Turn them only enough to free the arm.
Flip up the safety tab on the left crank and unscrew the preload cap with the Shimano tool. Take the cap out and keep it safe.
Pull the left crank arm off the axle, then slide the right crank and axle out of the bottom bracket. Watch for any spacers.
Clean the axle and the bottom bracket cups with a rag. Wipe off old grease and grit before refitting anything.
Undo the chainring bolts with a hex key and chainring bolt spanner. Lift the old rings off the spider.
Fit the new chainrings in the correct orientation and tighten the bolts evenly in a cross pattern. Grease the bolt threads first.
Grease the axle lightly and slide the right crank back through the bottom bracket. Refit any spacers in the same order.
Push the left crank onto the axle, fit the preload cap and tighten it gently until the arm has no play. Do not overtighten.
Tighten the two pinch bolts a little at a time, alternating between them, then check the cranks spin freely and the chain runs clean.
Tips and common mistakes
Grease the axle and bolt threads so parts come off easily next time.
Tighten the pinch bolts in small alternating turns so the crank sits straight.
Check chainring bolt torque and spin the cranks before your first ride.
Older or non-Shimano cranks use different removal tools, so check your model first.
Questions
Do I need a special tool to remove Shimano cranks?
You need the Shimano preload cap tool plus 5 mm and 8 mm hex keys. A chainring bolt spanner helps when swapping rings.
Can I reuse the chainring bolts?
Yes, if the threads and heads are in good shape. Replace any rounded or corroded bolts so they tighten properly.
How tight should the crank bolts be?
Follow the torque printed on your crank or in the Shimano manual, usually around 12 to 14 Nm for the pinch bolts. Use a torque wrench if you have one.
This guide was drafted from the video's details and general task knowledge. It has not been checked against the full video. Check the video and relevant product instructions before following a procedure. Report a correction.
