Home Forums Bike Forum Square taper bottom bracket stuck

  • This topic has 67 replies, 32 voices, and was last updated 3 years ago by nbt.
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  • Square taper bottom bracket stuck
  • nbt
    Full Member

    Trying to get a square taper BB out of a frame. The locking sleeve is out, but the drive side ain’t budging. The splines in the shell aren’t very deep, and whenever I apply pressure to the tool, it just slips out.

    Can anyone suggest a way to lock the tool into place? All the bolts I’ve tried have a different thread pitch to that of the bolt that locks the cranks into place. The spindle doesn’t have a hole all the way through so I can’t use a QR.

    I’ve seen (here) a tool that has a locking screw built in, which is for isis / octalink BB. I think the locking screw on these is wider than that in a square taper BB? Can anyone confirm? Or can anyone point to a similar tool for a square taper BB

    Isis Octalink tool with locking pin

    DezB
    Free Member

    Mine has a hole through the middle and always used to put a wheel QR through it to hold it in place.

    (I know you are, but you’re def turning it the right way?)

    fasthaggis
    Full Member

    If you get another tool without the pin you could use a bolt to hold in place.

    NewRetroTom
    Full Member

    I had a really bad one of these. I ended up taking the frame back to the framebuilder (it was a custom frame) and he used a blowtorch to get it out. Destroyed the paint, but got the job done!

    DezB
    Free Member

    Like this

    There’s a Cyclo one for £9.99 on Ebay. (Can’t do link on work PC)
    (or I’ll post you mine if you don’t wanna splash out)

    cookeaa
    Full Member

    G-clamp the tool into the cup?

    Or maybe Clamp tool in bench vice, place bike (wheels out) sideways on top of tool, relies on weight of bike to hold tool in cup, then use frame for more leverage?

    You only need to keep it engaged sufficiently to start the cup winding out of the thread.

    Stupid Question, you are turning it the right way? (Drive side is clockwise to loosen (LH thread)).

    tthew
    Full Member

    Getting a bolt with the correct thread pitch would be easiest solution. 10 seconds of googling suggests it’s M8 fine pitch. Got a long G clamp or framing clamp that would hold it in place loosely while you get it started?

    Also, (without meaning to insult your intelligence) you are turning it the correct way?

    edit – beaten to it while I was away!

    DezB
    Free Member

    Don’t ask silly questions cookkeaa 😉
    and tthew 😀

    nbt
    Full Member

    Mine has a hole through the middle and always used to put a wheel QR through it to hold it in place.

    Aye I’ve done that before but this one doesn’t

    I know you are, but you’re def turning it the right way

    Yep, got the new external BB next to this with the “tighten” indicator on it, so I know that I’m turning it the right way
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    Will triple check when I go back though just to be sure

    If you get another tool without the pin you could use a bolt to hold in place.

    I’m looking for a toll WITH the pin. My tool has no pin, just a hole, but I can’t find a bolt to fit – the thread pitch is different and I don’t want to wreck the threads in the spindle

    rossburton
    Free Member

    Last time I had this problem I ended up taking to my LBS who used an angle grinder on the bracket…

    nre
    Free Member

    Tool in vice and using the bike frame as a lever as suggested by cookeaa has always worked for me!

    nbt
    Full Member

    Getting a bolt with the correct thread pitch would be easiest solution. 10 seconds of googling suggests it’s M8 fine pitch

    Finding an M* bolt with fine pitch is the issue, found nowt in the garage and nowt in the local hardware store

    G-clamp the tool into the cup?

    WINNER – I have some G-Clamps, good call! I’ll try that later.

    Last time I had this problem I ended up taking to my LBS

    I had admitted defeat and was gong to use the LBS but they currently have a ten day backlog. I’m really glad they’re so busy but that thanksfully prompted me to ask on here…

    fasthaggis
    Full Member

    Last time I had this problem I ended up taking to my LBS who used an angle grinder on the bracket…

    If only someone had that photo of Kryton’s BB/crank grinder work… #legend 😊👍

    Murray
    Full Member

    Ebay for M8 fine bolt or your local fastener shop

    mick_r
    Full Member

    I always use a g-clamp as mentioned above. You can hoof it up tight on the drive side as cup / axle / bb usually come out as one (nds you have to back off the clamp as the cup comes out).

    Solid front hub cup and cone axles are sometimes M8 fine so a good source of threaded rod and nuts etc.

    tthew
    Full Member

    Yep, got the new external BB next to this with the “tighten” indicator on it, so I know that I’m turning it the right way

    That’s exactly my method. 😁 Pedals I do frequently enough to remember, but BB’s are just too irregular to be sure.

    ebay for odd fasteners ad Murray suggests. Bloody hell, they ain’t cheap though! 

    IHN
    Full Member

    I’ve got one with a hole in if you want to borrow it

    andrewh
    Free Member

    Are you absolutely, 100%, definitely, unequivocally sure that you’re turning it the right way?

    Yep, got the new external BB next to this with the “tighten” indicator on it, so I know that I’m turning it the right way

    If that new BB is an English thread and the old one and frame are Italian thread…. Italian ones are rare but google it and check!
    .
    I have loads of square taper crank bolts and a tool which I know is a shallow enough depth to use them to hold it on to the BB. If you are anywhere near the Tweed Valley you are welcome to pop round and use them, pm me.

    MrTricky
    Free Member

    I’d also put a lot of oil inside the frame and leave it (on its side) to penetrate overnight before trying again

    squirrelking
    Free Member

    I had one like that, turned out sitting the frame upright on the floor and standing on the tool was enough to get it moving. Couldn’t budge it by hand or get the tool to stay in like you but that just worked first time.

    StuF
    Full Member

    Was about to suggest the ‘italian’ standard which is the same both sides, rather than the english which is opposite to the direction of the cranks (making sure it doesn’t loosen as you pedal)

    thepurist
    Full Member

    MrsP once caught me getting the angle grinder out to “deal with” such an issue. As it was her frame she opted to try herself, clamped the tool in place and then just spent an age tapping the spanner with a hammer (and I mean tapping, not belting seven shades of sh out of it) and whaddyaknow, the damn thing came undone. I will never ever be allowed to forget this.

    sbtouring
    Free Member

    I use my dewalt 1/2″ impact driver. Will have it out in seconds.

    For years I would use methods mentioned above to hold the splined tool in place. But impact driver just gets it done quickly without putting much strain on the frame. I use it now for all mine bb’s.

    Only problem is you need an impact driver or know someone who has one.

    plus-one
    Full Member

    Tool in bench vice and use frame as big lever. Never failed me yet 🙂

    nbt
    Full Member

    If that new BB is an English thread and the old one and frame are Italian thread…. Italian ones are rare but google it and check!

    It’s a Mk2 On-One Scandal, 73mm english thread

    I’d also put a lot of oil inside the frame and leave it (on its side) to penetrate overnight before trying again

    It’s had several soakings

    I had one like that, turned out sitting the frame upright on the floor and standing on the tool was enough to get it moving. Couldn’t budge it by hand or get the tool to stay in like you but that just worked first time.

    If the tool ould stay on, I’d have done that a while ago

    Only problem is you need an impact driver or know someone who has one.

    Good idea, but I don’t have one and don’t know anyone handy who does have one

    However, I do have a g-clamp and I’m prepared to use it

    matt_outandabout
    Full Member

    I had old Specialized that we:

    – soaked in plusgas. for three days.

    – heated up frame & iced bb axle.

    – bolted in the new long spline tool, tight.

    – used good ring spanner. With the old bike stand pole on the end of – approximately 5′ lever.

    – used two boys and myself to hold frame down to the ground – and sent third boy out to the end of the pole

    …….where a few pushes with legs from teetering boy led to a satisfyingly slow movement of the BB.

    I honestly thought I was going to break the frame – you could see the alloy rear triangle flex…

    b230ftw
    Free Member

    If you are anywhere near Huddersfield I can get it out for you for a small charge. No damage to frame.

    tthew
    Full Member

    Only problem is you need an impact driver or know someone who has one.

    Good idea, but I don’t have one and don’t know anyone handy who does have one

    A local mechanic would have a windy gun and as suggested would probably take seconds. If your tool has a 1/2 inch drive, take it all round there, armed with a couple of decent packets of biscuits and your most suggestive smile, they’d likely help.

    To those of you saying have at it with an angle grinder, WTF is the technique you’d use to extract a stuck BB from a frame?? I really can’t imagine how it could be effective.

    fossy
    Full Member

    Long g-clamp and some wood will do it.

    Had a similar issue with locking nuts on my son’s car – one was a little too tight, but the tool kept popping off, and he’d already ruined one as they were made of cheese.

    Googled, solution was to park the car near the wall of the house, then just the scissor jack to press the locking tool onto the nut (with a bit of wood) – undid easy, no force needed.

    A long g-clamp will hold it in place. (or get another tool that will accept a QR)

    nbt
    Full Member

    or get another tool that will accept a QR

    the tool is fine, it’s the spindle in the BB that won’t accept a QR

    DezB
    Free Member

    The axle doesn’t have a handily QR sized hole down the middle? What do the crank bolts screw into?
    Sorry that’s an unnecessary question. I’m bored, I do apologise

    fasthaggis
    Full Member

    Dez..Usually blind threaded holes about 25mm deep,you had a rare thing if you could put a QR all the way through it.

    Murray
    Full Member

    The ones with through holes were the posh lightweight ones!

    bigblackshed
    Full Member

    6435-A6-AB-C980-43-BE-8-A0-B-2-A45-CE4-FA819

    Sensible answer if the G clamp method doesn’t work is the soak in PlusGaz and an impact driver.

    DezB
    Free Member

    you had a rare thing if you could put a QR all the way through it.

    I don’t think Shimano UN72s were that rare!

    fasthaggis
    Full Member

    Hmm,I thought all the shimano sq taper were solid, #everydaysaschoolday 🙂

    DezB
    Free Member

    I’ve still got 2 UN72s and 2 UN73s! #hoarder

    😛

    fasthaggis
    Full Member

    Brilliant! 🙂

    kcal
    Full Member

    My ST BB is seized in the frame of my old M2, and there I think it will remain!

    It has made me review the number of ST BBs I have in my spares drawer 🙂

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