Sheared bolt with a 3mm hole in it!

JuanLobbe

Über Member
Location
Sale, Manchester
When I first got my bike I accidentally sheared off one of the bolts used to attach stuff like water bottle holders to the frame. It's been bugging me for about two years as I can't attach things there and I want to be able to!

So last night I decided to try and use a screw extractor kit. I managed to drill a 3mm hole in the bolt. However I cannot get the bolt out using the kit.

Questions:

1. Might a good bike shop be able to do it?
2. With a small hole in the frame, how much of a problem could water getting in be? It's the diagonal part of the frame.
3. If the bolt can't be removed, would taping it up work or will it need soldering?

Please help this technical ignoramus! :laugh:

thanks.
 

accountantpete

Brexiteer
I take it that the head of the bolt sheared off.

If you have drilled a hole in the bolt then you should be able to work a tapered screw into the hole and then either screw the bolt into the frame and get it out via the BB etc or put a bit of superglue on the screw and then unscrew as normal when set.

I'd plug the hole first and then pop some WD40 on the bolt to make sure it is free.
 

battered

Über Member
Watch it with cheap screw extractors. They are very hard and prone to breaking, esp fine ones. If one breaks in the hole you have a worse problem than before.

I've spent a lot of time messing around with old cars where this is commonplace. The best trick I know is to drill a hole through the bolt (all the way) as big as possible without touching the frame. You then get a Torx fitting that is just too small for the hole and drive it in with a hammer before winding out the remains.

The bike shop will sort it no problem.
 

Gareth

Veteran
I started out over 30 years ago in the world of Agricultural Engineering, and so removing sheared, seized and corroded; bolts, screws and studs were and still are common part of my job.


For the removal of sheared and seized small diameter screws, and bolts commonly found on Bicycles I have found this product to be absolutely ideal:

http://www.screwfix.com/prods/21391...s?cm_re=SEARCHPROMO-_-SCREW EXTRACTOR-_-21391

However, the extractors have to be used in a pistol drill that has a reverse drive function.
 
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