Chainring bolt snap...
 

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[Closed] Chainring bolt snapped in cranks. Help!

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Mid build of my Solaris Max (I say build...more of a parts swap) and I notice that one of the 4 bolts for the XTM8000 crankset has snapped in half - no idea how. Wasn't too tight...just seems to have perished. The upshot being that I now have half the chainring bolt deep in the crank spider.

Any ideas how to best extract it if possible?

I could run 3 bolts, but there is slight movement and so doesn't fill me with confidence.

Or I could just get a new chainring, use 3 bolts, epoxy the 4th to add a little stability and bin the cranks when the chainring dies (have 5k miles out of the old ones)

or for £100 - just get new cranks with boost spacing instead.

Ideally I am looking for a simple way to remove the old bolt without totally buggering the thread of the spider!

thanks


 
Posted : 02/01/2020 4:21 pm
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Is the bolt hollow or solid?

I'd have thought that it it's not under tension it won't be tight, can you get eg: needle nosed pliers into the remains, pull them apart and grip the bolt enough to turn it out?

Or a bolt extractor https://www.screwfix.com/p/bolt-extractor-set-5-pieces/1112V?tc=PT5&ds_kid=92700038875437667&ds_rl=1241687&ds_rl=1245250&ds_rl=1244066&ds_rl=1245250&ds_rl=1247848&ds_rl=1248184&gclid=Cj0KCQiAxrbwBRCoARIsABEc9sjy7q9cX0lIAYn8tfOan7d6kCuMhuaTBfWeIGUpCge-iurSoqz8PScaAgvxEALw_wcB&gclsrc=aw.ds

would work if solid and you drill a pilot hole first, or if hollow you may be able to find one that's a suitable size to cut in on its own.


 
Posted : 02/01/2020 4:28 pm
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Pretty sure it’s hollow but I’d have used some medium thread lock when installing. And it’s been in place for 4 years... so not sure how easy a grip and turn will be.


 
Posted : 02/01/2020 4:42 pm
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Get it warm to soften the loctite then an eaziout, as linked above, should bite nicely into the (ally?) bolt.

Or a left handed drill may work it out as it'll try and unscrew it as it cuts.Probably needs more care to avoid knackering the crank thread though...


 
Posted : 02/01/2020 4:48 pm
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Stick a sacrificial torx bit in and give it a ho


 
Posted : 02/01/2020 4:56 pm
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Picture?


 
Posted : 02/01/2020 7:03 pm
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Bolt extractor should work, although medium threadlock on fine pitch thread might be overkill and make it harder to budge, if there's a few threads showing try a shorter bolt if the extractor fails or carefully drill out with 6mm bit then 6.5 then 7mm bit and pick out the remaining bits of alloy bolt.


 
Posted : 03/01/2020 12:50 am
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Update - a couple of different sizes of Eazyout did the trick! Thanks STW!


 
Posted : 06/01/2020 1:16 pm

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