Uh Oh. Snapped Off A Hex Key In A Bolt Head.

[Bazzer]

Apologies if I gave the impression the bolt remover tool is potentially destructive. The tool itself is turned by hand in an anti clockwise direction and is relatively benign. It bites into the metal and as it rotates anti clockwise it unscrews the bolt. Out it comes. I've had a couple of 'miracle' moments when you see that bolt start to come out - it's a cracking little tool. The bolt may even be reusable but if it were me I'd have a replacement on hand just in case. I presume it's a bog standard bolt, even though it's recessed?

^^whs^^ thread extractor

 

[Lovacott]

If it's a ball end key, I've had the same happen on good quality (Wera) keys, although mine get used daily. They snap at the weakest spot, the narrow point between the shaft and the ball end.

It's a 2mm standard Allen key which I can't remember ever using before (the rest of the set have done hundreds of things without issue).

It's just one of those stupid and irritating things that happen when you decide to do a five second job.

I could write a £ukcing book about five second jobs that went tits up.

 

[Lovacott]

If it really wasn’t under a lot of pressure then it probably isn’t very firmly stuck. I realise it’s small, but can you get a small punch on it, and tap it in the reverse direction? If you don’t have a tiny/sharp punch then maybe a small nail or screw?

I'm going to try it using a sewing needle as a punch in the morning.

I'd do it now, but I'm on my third can watching the bindippers play the toffees.

 

[Oldhippy]

Sewing needles are very brittle. Be careful!

 

[Lovacott]

Sewing needles are very brittle. Be careful!

As are 40 year old 2mm hex keys.

 

[Randomnerd]

Man loses eyeball in garage, repairing a bike with a sewing kit. FFS don’t use a needle. Screw extractor maybe but it’s likely to need a HSS one. You not got a friendly mechanic? He will have one.

 

[Lovacott]

Man loses eyeball in garage, repairing a bike with a sewing kit. FFS don’t use a needle.

The needle would only be used to nudge the remnants of the key to the left a tiny bit.

But don't worry. I will be wearing a full hazmat suit throughout the entire process.

Safety first and all that...

 

[Gunk]

Front clamp bolt should be tightened to 7 Nm max, how on Earth did you manage to snap off an Allen key!

only way of resolving it is to cut the head off with a Demmel and drill it out. Or sell the bike!

 

[HMS_Dave]

Smash it with a lump hammer. If bits fall off, put it in the bin...

 

[Lovacott]

Front clamp bolt should be tightened to 7nm max, how on Earth did you manage to snap off an Allen key!

only way of resolving it is to cut the head off with a Demmel and drill it out. Or sell the bike!

It's not the clamp. It's the cable tension adjustment.

The little bugger in the picture below.

 

[Lovacott]

Smash it with a lump hammer. If bits fall off, put it in the bin...

Have you ever considered a career in marriage guidance?

 

[Smokin Joe]

I could write a £ukcing book about five second jobs that went tits up.

I could contribute the second volume.

 

[gbb]

Front clamp bolt should be tightened to 7 Nm max, how on Earth did you manage to snap off an Allen key!

only way of resolving it is to cut the head off with a Demmel and drill it out. Or sell the bike!

I use Allen keys every day at work, I've had one snap using very little force. I suspect its partly design, partly maybe manufacturing defect. It's also the 2 mm key, its tiny anyway..

 

[Lovacott]

I use Allen keys every day at work, I've had one snap using very little force. I suspect its partly design, partly maybe manufacturing defect. It's also the 2 mm key, its tiny anyway..

I've just spent five minutes looking at it through a magnifying glass and the cross section surface of the broken key has an area which looks like the inside of a Crunchie bar. Whether that is how it was already or if it is the result of the snap, is not for me to say.

The bolt itself does the same job as a standard front mech barrel adjuster and with a bit of thought, Shimano could have made the bolt head a barrel adjuster instead of a hex. Cable tension is pretty critical on two ring systems with trim settings, so it's an adjustment which would need to be made more frequently than on (say) a three ringed MTB.

I've become used to "on the fly" minor gear and brake adjustments using just the barrels. Now, I find that my top of the range front mech requires a tool to do something I can do with my fingers on my bargain basement Apollo.

 

[Illaveago]

So we are talking micro surgery ?
The Allen key is 2mm AF so you you are going to need a good head magnifying lens to see what you are doing .
Just thinking about the problem is difficult enough !
If you could get a good 1mm drill to make a hole in the remains of the Allen key it might loosen enough to come out if you are lucky .
Super glue might make things worse as it could spread around and glue the bit in .
I don't envy you !
So you are going to need to have steady hands and mount the bike securely so that it doesn't move at all .
If the action of the drilling doesn't shift it then you will need to resort to an extractor of some kind . Perhaps a soft wire which could be super glued in and then gripped with a pair of moles and pulled out . I wouldn't use anything hard as if it broke off you would be in a worse position .
Good luck with whatever you do .