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Is there anyone who has had luck using a 2 or 3 arm crank puller to remove the crank arms off a tapered bottom bracket?

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    Why not just use a standard crank puller? (I assume what you're describing is a "gear puller".) Oct 2 '20 at 23:29
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    I'll add that the main reason for using a gear puller would be if the threads inside the crank had gotten stripped, so a conventional bike crank puller wouldn't "grab". But a gear puller would be futzy to use. Oct 2 '20 at 23:51
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    If you can't pull them with a conventional crank puller, would it be prudent to reinstall l them - the next mechanic might be a psychopath who knows where you live :). I suspect if you factor in the cost of the swear jar, drilling and splitting the cranks then buying new ones would be cheaper.
    – mattnz
    Oct 3 '20 at 0:17
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    This is obviously an XY problem. See bicycles.stackexchange.com/a/2185/683 for info on removing square taper cracks with trashed threads. Oct 3 '20 at 2:05
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    Unlike people who want to claim XY problem on everything, I can't read OP's thoughts. The other plausible explanation is that they already have a gear puller and want to use it instead buying another special tool but also want to ask before potentially damaging the crank.
    – ojs
    Nov 3 '20 at 7:50
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While Chris Dottavi mentionned that jaw pullers are not meant to remove crank arms, they can definitively used for that, although you might want to think bit before doing so.

I do work in a community bike workshop, where we have a lot of people comming with bicycles that can be quite old or in bad shape. It is therefore not always possible to use the usual crank puller. Therefore, we sometimes have to do otherwise. For the sake of completeness, here is the list of things I have done, in order of preference.

For recent (squared) bottom brackets:

  • try with a regular crank puller, if you have the right one (check the standards, in particular if you have an odd bike).
  • try with a jaw puller. Depending on the jaw puller and the shape of the star of the right crank, it might be more or less easy to grab it (for instance, if you have a "5 leg" spider to hold the crankset, it might be difficult to place the tool if you use a 2 jaws puller). Also, depending on the end of the screw of the puller, you might want to keep the crank screw (just unscrew it for a few turn). Indeed, if the screw of the puller is to small, it can destroy the threading of the axle (happens almost never, but not never). The main advantage of that technique is that, if you are careful, it most likely preserves the crank (assuming you are interested in keeping the crank, e.g. if you did not have the right crank puller).
  • unscrew the crank screw, and go for a ride. I rarely do that, since it might require some time (and, at the workshop, we can not really say: "take a ride and come back"), but it most likely work, often quickly. Some drawbacks: if you have aluminum cranks (most likely on modern bikes), you do not want to ride with the loosen crank: the squared shape hole will quickly not be that square anymore (once again, if you intend to reuse the crank).
  • with a torch, you can warm the crank, so that it expands (faster than the axle). I've done that only once, so I can not really tell some advices
  • Finally, if, with all that, the crank is still tight, you can cut it with an angle grinder. Take care of where you cut, as you do not want to cut the axle or the frame. I usually do three cuts. This is really last resort: the crank is (of course) not reusable, but it is also quite likely that the axle get damaged too, sometimes the cup too. While wuite extreme, this is sometime the only way to recover some frames.

For older (cotter) axles/cranks: You should not have any problem with those, once the cotter is removed. If you have, you can hit (gently) the crank with a hammer, or use a jaw puller.

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Thing is, gear pullers come in many sizes and styles. One is needed that will reliably grip the back edges of the crank arm without sliding off. Some styles would do this quite easily, while others would be a royal pain to use.

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No, 2 or 3 jaw pullers are not meant for removing cranks off a tapered BB axle.

I recommend going to a local bike shop and asking them for a tool to buy or what tool so you can buy, or just ask them to do it for you.

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