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How do I remove BBS02 crank arms so that I can tighten motor mount?

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    How do I remove BBS02 crank arms so that I can tighten motor mount?

    Hi there, I put together a Luna BBS02 750w mid-mount kit last year and have noticed that the engine mount has loosened. Unfortunately; I don’t remember how the cranks went on, and when I removed the nut that holds it in place, I’m not able to pull the crank off. I vaguely recall just sliding the crank over the spindle, but perhaps I had to screw it on? At any rate, I’m not able to remove the crank arm. Do I need a special tool, or is there a proper technique for removing? Any suggestions on how to do this would be greatly appreciated.
    Thanks, Shrekkie

    #2
    Hi - there is a specialized crank extractor tool that threads into the crank arm. The good-enough version of the tool is available online for less than $10 from the usual large retailers (eBay, Walmart, Amazon), and typically looks like this:
    Click image for larger version  Name:	3427936d-f95b-4278-8c00-a70f145d1d2e_1.b888bebc3157ba3ceefccfd82c54ec97.jpeg Views:	0 Size:	17.2 KB ID:	109109




    Any decent bike shop in Toronto has the tool as well, and if you don't want to own it I suspect they'd pull the cranks for approx $10 of shop time.

    Once the crank is off, you want to tighten HARD the steel, 4-notch ring under the aluminum cosmetic ring - I mean, lean into that Luna sheet wrench you have.
    Last edited by ncmired; 07-05-2020, 08:12 AM.
    BBSHD/BBS02B builds: IGH 1 2 3 4 5 6

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      #3
      Hi ncrkd,
      Many thanks for responding so quickly. Ok, I'll look into getting that tool. I probably will need to get the BSB-1 STABILIZER BAR FOR BBS02 AND BBSHD to securely mount the engine, but unfortunately, it's sold out at the moment. So, it makes sense to get the crank extractor tool so that I can tighten the engine as required until I'm able to properly secure it.
      thanks again, Shrekkie

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        #4
        Hi ncrkd,
        Sorry, one more clarification, if you don't mind. These are the Bafang cranks that came with my BBS02 mid-mount kit. Do I still need the specialized crank extractor? I know that I had to use that to get my original cranks removed (which I was able to do through a DIY bike store that loaned out the tools), but these cranks had a nut that was removed from the centre, so I thought they were a different sort. However, this is the first time that I've had to remove them. thanks, Shrekkie

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          #5
          The Luna crank arms are likely the same as the previous ones you had, as in they're pressed onto the bottom bracket square-taper spindle by the center nut/bolt. After reassembling everything you'll also want to check/retighten that center nut/bolt after the first few rides.
          Last edited by ncmired; 07-05-2020, 08:29 AM.
          BBSHD/BBS02B builds: IGH 1 2 3 4 5 6

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            #6
            Once again, thanks so much for your excellent advice and prompt responses. Appreciate your patience and the knowledge that you have imparted. I will order that extraction tool right now, as I've noticed that our local adventure/outdoor shop called MEC no longer stocks them. Shrekkie

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