Changing your cranks is easy with the right tools. While I was pulling Prudence apart I thought I would take the opportunity to do a ‘How-To’ on removing square taper cranks, as this is the most common system for connecting cranks to the bottom bracket of a bike.
The tools that you will need for this job are the Park Tools CCP-22, which you can get for less than $25 on Wiggle, some lube, and a socket set (a good one is a must for anyone contemplating bike mechanic-ing).
1. Remove the dust cover
I was unlucky that the dust covers on Prudence’s old Sugino cranks had become brittle over the years and could not be unscrewed, because the plastic snapped when any force was applied. This meant I spent some time chipping away at it with a screwdriver, I was lucky not to ruin the thread inside the crank! Hopefully the cap on your cranks is in better shape.
2. Remove the bolt
Next, using your socket set you remove the bolt that attaches to the spindle of the bottom bracket. Most times I forget this step and feel the fool when there is no way I can get that crank arm off! If there is a washer in there you should also remove that.
3. Lube up the crank
Get some WD-40, silicone or grease onto the thread inside the crank. This will help the crank come off more easily and reduce the chance of the the crank puller getting threaded or stuck.
4. Prepare the crank puller
Check you have the right size crank puller for your cranks (hopefully you will have ensured this when you bought it, but you might be borrowing it off a friend, so it’s good to double check). Unscrew the centre piece of the tool as far out as it will go (this is the thin section attached to the handle), or you could just remove it entirely, this will ensure the fat part of the tool will screw in as tight as possible.
5. Use the crank puller
Screw the fat part of the crank puller into the crank, being careful to screw it in straight. Make it as tight as it will go then tighten it with a wrench if you have one available. Finger tight was fine for me, but you risk ripping out some threads if it is not screwed in deep enough. Screw the centre piece of the tool in and keep spinning it until the crank pops off, sometimes it comes off easy, other times it might require a bit of force. I find it easier to spin the cranks rather than the handle on the tool, because there is more to hold on to.
Repeat the whole process on the other side.
Remember: bike building and maintenance isn’t hard but it is great fun!