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In my (first) attempt to remove the crank arms from a bike, I broke the crank puller (Super B TB-6485). I applied more force than I was comfortable with, thinking the threads had perhaps rusted over time. When attaching the puller to the crank, I pulled back the driver a fair bit from the coupler, screwed in the coupler, tightened it lightly with a spanner, and then proceeded to turn the driver down as far as I could. I then applied as much pressure as I could, and I heard it snap. Uncoupled everything, and the two bits seen in images 1-3 fell to the ground.

What did I do wrong here? Can the tool be used without the parts that fell out? Should I have removed them beforehand? I'm honestly a little confused as to their function.

Thanks in advance. Images below.

Puller assembled

Puller disassembled

Pin with 2.5mm hex socket (3/32") snapped at the thread

Square tapered spindle scratched, but seems sound

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    I've never even seen such a gizmo as that "top hat". Used that style of puller (though Park Tool brand) many times with no problems. – Daniel R Hicks May 7 at 16:56
  • @DanielRHicks the Park model with the (blue) handle is specific to square tapers, hence your success rate. They also do a black handle one which is the larger type, so they are separate tools. The CWP-7 meanwhile has adapters for both types but no handle. – Swifty May 7 at 20:56
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You shouldn't use the little adapter that you can disassemble from the tool for a square taper crank. Check, but you should find that it has a larger diameter than fits through the square hole in the cranks. It is used for Octalink, ISIS etc cranks with a larger spindle.

What I think happened is you got a little way with the tool, then the adapter bottomed out against the crank itself (not the spindle). You were then effectively trying to pull the tool apart against itself, and succeeded.

You probably don't need to buy another. You should be able to use the disassembled puller to remove the crank, and the adapter should still work on suitable cranks, just not this crank or other square taper ones.

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  • Thank you, Swifty. This sounds exactly right, and it makes sense that it would be an adapter for other cranksets. I will give it another go later. – Wehage May 7 at 16:27
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I have owned own a Park Tool version of this tool since 1988, and it has given me great results. If your tool works like mine, here is how to use it: After removing the cap from the crank, one side of that threaded cylinder should thread down into the crank. Screw it in all the way. Then take the handle park and screw it into the cylinder. Eventually you will feel it bottom out on the end of the spindle. Keep turning, and you will notice it pulling the crank off. After one or two more turns, it should slide off. I am not sure what the other two parts with your tool do. Maybe adapters for oddball crank designs?

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  • Thank you, bradly. Your instructions are similar to what I've read elsewhere, but after bottoming out the spindle driver, it simply would not budge any further. Perhaps it will work as you're describing now that the other two parts are out. I will try that later today. – Wehage May 7 at 15:56

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