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Sram S1400 crank removal from a BB30 bottom bracket

brent1975brent1975 Posts: 8
edited July 2018 in MTB workshop & tech
Hi! I am trying to replace my existing Sram S1400 crank on my 2014 Cannondale F29, but the spindle seems reluctant to leave! Any thoughts? I have tried tapping it with a mallet, but I am not sure how hard I can hit it without breaking something I am going to regret breaking. I have read penetrating oil might work, any recommendations for a particular oil. I have also read that spraying a can of compressed air (while upside down) to cool the aluminum spindle (and shrink it) might also work. Has anyone tried this approach? How many cans I should I dump into the inside of my crank spindle? Thanks in advance for any recommendations.

Posts

  • JBAJBA Posts: 2,706
    Hit the end of the spindle a bit harder. Use a rubber mallet or put a piece of wood across the end of the spindle if using a metal hammer.
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  • The RookieThe Rookie Posts: 27,748
    Its a light interference fit in the bearings and can need quite a sharp tap to get it moving. As above a block of wood to prevent damage is a good idea. A rubber mallet isn't the best if you go that route, fibre or nylon head.
  • brent1975brent1975 Posts: 8
    With my crankset, I remove the DS crank arm, how do I support the frame while I'm trying to whack the spindle through with a hammer? How easy is it to reinstall?
  • 02GF7402GF74 Posts: 1,294
    On the spindle there are two machined lands, these are of slightly larger diameter than the rest of the spindle, and it is on these that the BB bearings sit. Sometimes they can get a bit rusty so some penetrating fluid won't go amiss.
    .

    The way I do it is to rest bike upside down on saddle and bars, stand so my legs rest against the frame then whack the spindle with a rubber mallet.
  • brent1975brent1975 Posts: 8
    Has anyone tried the can of compressed air method? Tried again with a hammer, but it’s still not coming moving.
  • The RookieThe Rookie Posts: 27,748
    I cant see how you can use compressed air at all.

    I just stand it on its wheels and give it a 'tap', as above the part of the axle where the bearings sit is a slightly larger diameter, so once it's moving it comes out fine.
  • brent1975brent1975 Posts: 8
    I haven't used the can of compressed air method yet, but it involves dumping the contents of the can (while the can is held upside down) into the spindle. The contents, the hydrofluorocarbons come out as an cold liquid that causes the aluminium spindle to contract slightly, and hopefully enough to ease the resistance with the BB30 bearings. Failing that I will try a penetrating oil like Duck Oil.
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