Oh Poo, I've b...
 

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[Closed] Oh Poo, I've broken my Middleburn BB 🙁

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Because the weather has been so nice this weekend I decided to take time out and give the bike some TLC. The BB needs new bearings, normally an easy job unless the crank retaining bolt shears off in the axle during disassembly. Botheration and drat. All is now removed from the frame and I'm going to fit another BB as a get me by whilst I try to get the sheared off bolt removed.

Any suggestions? It is a Ti axle with a Ti bolt sheared of inside it.


 
Posted : 05/02/2017 1:57 pm
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Ti with Ti that's going to be well stuck. 🙁 best of luck saving the BB.


 
Posted : 05/02/2017 2:15 pm
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Fit a Shimano UN55, they don't break. I wouldn't even bother trying with the Middleburn. Using titanium for crank bolts is daft too. It's not strong enough, as you've just found out. My guess is you've had those boots/cranks on and off a few times, right?


 
Posted : 05/02/2017 2:19 pm
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What state is it in currently? I assume the bolt head sheared but left the threaded section behind.

Any exposed thread left?

Any copaslip on the threads last time it was out?

Is the axle hollow and open from the other end?


 
Posted : 05/02/2017 2:22 pm
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File flat is what remains of bolt, then spanner or vice.

Replace with steel


 
Posted : 05/02/2017 4:15 pm
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It has sheared off within the axle, no chance of filing flats onto it whatsoever 🙁

Axle is hollow and threads are/were coppaslipped.

UN55 is on it's way already but come on- it's a Ti BB and I don't want to lose it 🙁


 
Posted : 05/02/2017 8:54 pm
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Drill the bolt and try an extractor fingers crossed the copper slipp has prevented to much of it being stuck solid.


 
Posted : 05/02/2017 8:58 pm
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Can Ti be drilled similarly to steel?


 
Posted : 05/02/2017 9:02 pm
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If it's hollow, try a long drill bit from the other side. At least the rotation is in the same direction to drive the bolt out. The tenstiin should have come from the head which is no longer there. The thread should come out fairly easily, the trick is getting hold of it to turn it.


 
Posted : 05/02/2017 9:05 pm
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So there is still some hope?


 
Posted : 05/02/2017 9:06 pm
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Possibly. If the thread was ciuntersunk at the end, you'd be a very lucky man but I doubt it will be. It's possible the thread has galled, ti on ti can do, but there's a good chance it isn't.


 
Posted : 05/02/2017 9:09 pm
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Ooops- not Middleburn but Royce. It's still the same problem though 🙁


 
Posted : 06/02/2017 6:29 pm
 mrmo
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http://www.royceuk.co.uk/Bottom-Bracket-Axles-Tapered-Square/

contact and see if they can offer some advice. The worst they can say is no.


 
Posted : 06/02/2017 7:09 pm
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[url= http://www.screwfix.com/p/screw-extractor-5-piece-set/18643 ]easy out worth a pop?[/url]


 
Posted : 06/02/2017 7:40 pm
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I've never seen an easy-out work. I've seen several break off and make subsequent drilling extremely difficult - I wouldn't bother unless you've got access to a spark eroder to remove it when it snaps!

I'd try and drill it out until you're almost at the minor diameter of the female thread - should then be able to get the remains out with a pointy implement.


 
Posted : 06/02/2017 8:44 pm
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Can I do this to titanium? How does it compare to steel?

I called in at a local engineering place today but it was after hours and no-one was available to help 🙁


 
Posted : 06/02/2017 8:53 pm
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You've never seen an easy out work?? I've used an old snap on set to great success hundreds of times (removing rounded aircraft fasteners) the trick to using them is drill, drill and drill some more, if you think you've drilled enough drill some more, you need at least half the length of the easy out to be in the hole before you start, and tap with a hammer quite hard as you're turning.


 
Posted : 06/02/2017 8:56 pm
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That link didn't work


 
Posted : 06/02/2017 9:01 pm
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Ambrose - Member

Can Ti be drilled similarly to steel?

It's a bollocks to drill tbh. It doesn't conduct heat away that well so it's easy to overheat the drill bit, and it work hardens. (and I think some alloys heat harden too? Not sure. Seemed to, when I was working on my old exhaust, heat cycling it was a total ****up so I always tried to get everything done with the first cut and tons of cooling.

I don't really know what the part's worth but the thing with bolt removal is that often you only get one good shot at it, so in something really critical it's often worth getting in the pros- failure can make it harder to remove.

Thing is, it was stuck enough to break- now that could be because of bolt stretching under tension, or because of the bolt being galled or otherwise stuck against the arm, which could mean that it's now less stuck, but that's optimism. When moving a stuck bolt, unless you take other action (gas axe or other local heating, or you manage to get penetrating oil into it, or similar) then you need to produce a bigger force than you did already. So a crappy screwdriver slot dremelled onto it isn't likely to cut it. Sometimes with a left handed drill bit you get spawny and the combination of heat and rotation just walks it out...

Easy-outs when they work are great. When they don't work, you end up with a broken easy-out stuck in the bolt. Cheap ones are shit ime.

I own a suzuki motorbike so I got pretty good at removing stuck bolts. But it's a bollocks of a job sometimes and it's very easy to make things worse.


 
Posted : 07/02/2017 12:29 pm
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Yayyy! Result. I dropped in to the local engineering shop this afternoon, Global Engineering, near Ammanford.

It is a very male environment- lots of calendars with ladies wearing clothes totally unsuitable for the current weather conditions, lots of naughty words being shouted at each other. But hey ho, after 3/4 hour of drilling, picking and tapping I have my BB axle back all cleared out and ready to go. All for a tenner.

I'm smiling.

http://globalprecisionengineering.com/


 
Posted : 21/02/2017 8:27 pm
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That's a result and are they really on just £13 p/h?


 
Posted : 21/02/2017 8:43 pm
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They are probably on a lot more than that- but all they asked for was a tenner for the Christmas drinks kitty. I did offer to sort the guy's rear mech though, he can't get it to shift nicely.


 
Posted : 21/02/2017 10:11 pm

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