Help! Chewed allen bolt

[DC29]

Hi guys, just wondering if anyone could help me. I was having difficulty getting my allen bolt to loosen on my bike which ended up getting chewed. Now while trying to fix it a drill bit had snapped inside it. Any ideas what to do? Thanks

 

[Funkeydunk]

Undo the bolt from the other side of the bike, if you can

 

[Planemo]

Carefully cut a slot in it with a dremel and use a quality large flat-bladed screwdriver. I have some drivers with an 8mm hex at the top of the shaft to provide some additional leverage with a spanner. If you don't have the hex, try the old kerbside autos method of clamping a set of mole grips onto the shaft super tight.

 

[DC29]

Undo the bolt from the other side of the bike, if you can

Unfortunately it doesn’t turn from the other side

 

[DC29]

Carefully cut a slot in it with a dremel and use a quality large flat-bladed screwdriver. I have some drivers with an 8mm hex at the top of the shaft to provide some additional leverage with a spanner. If you don't have the hex, try the old kerbside autos method of clamping a set of mole grips onto the shaft super tight.

Thanks I’ll give this a go

 

[Zimmerframe]

The other thing to do is hammer in a Torx drive.

Bodge it !

This post has been sponsored by Sam Pilgrim .. After yesterday's awesome day of tool destruction and converting a torque wrench into a much more useful torque hammer. We headed off to find something new to destroy ! Today's bodge - removing the rear axle .. I actually used a torque wrench...

www.emtbforums.com

I keep meaning to change the axle, but it's still working fine in it's "bodged" state ..

 

[towzer]

This Might not work (*old motorbike seized screw etc trick), and take care as not much metal on a bicycle. but fyi, Can you punch/chisel (with a sharp punch or small sharp chisel(even flat screwdriver), hitting it in (gently) with a hammer, , create a indent in the outside edge of the bolt head (by punching/hammering straight down) and then once you have created a small indent then use the indent to punch/hammer the bolt in the undo direction.

 

[steve_sordy]

Be certain to know which way to loosen the Allen bolt and which way the black thing with the writing on it.
You can never be too careful with bikes. They are the only thing I have come across where left-hand threads crop up, and not just on the pedals!

 

[Stihldog]

I’ve only used these twice but they saved the crank. 9/16” left and right thread taps.

When I’m not sure of the type of thread used (left or right) I sometimes use a torque wrench with the correct setting which can tighten or loosen a bolt. I stay within the torque specs and try to turn the bolt both ways. There’s less chance of a damage when the right sized socket or Allen key is used.

 

[p3eps]

I bought these for that exact reason. They’re specific Allen bolt removers for when the heads get slightly rounded.

I was looking at thePark Tools THH-1 Allen key set the other day, and they have these fitted to one end.

I think you need to try and get the broken drill bit out, and then use something like this to remove the bolt.

 

[B1rdie]

It seems to be a counter clockwise threaded bolt, so you can use a regular drill to make a hole and a superb screw to drive it out. 20 nm is a very light torque, so, if turned on the right direction it should not be too hard to remove it.
If it is a regular clockwise tightening bolt, you can find counter clockwise drills and superb bolts to do it.

 

[Funkeydunk]

Unfortunately it doesn’t turn from the other side

I’m fairly confident the through axle unscrews from the none drive side. Is it a haibike?

 

[DC29]

I’m fairly confident the through axle unscrews from the none drive side. Is it a haibike?

No it’s a Lapierre. The other side is just a hole with no bolt or anything to turn

 

[RustyMTB]

Probably Stihldog or P3eps posts are the ideal tools. Otherwise, this impact screwdriver is the single best tool I've ever owned for these situations. If you can get a bit to fit, it uses shock force to turn a fixing & it's very effective.

 

[Funkeydunk]

No it’s a Lapierre. The other side is just a hole with no bolt or anything to turn

Can you take a pic of the other side. Just in case?

 

[Stihldog]

Probably Stihldog or P3eps posts are the ideal tools. Otherwise, this impact screwdriver is the single best tool I've ever owned for these situations. If you can get a bit to fit, it uses shock force to turn a fixing & it's very effective.

View attachment 126869

Yes. That with a Torx bit might be the answer.
@p3eps bits also.

 

[theremotejuggernaut]

I don't think extractors are the answer in this case. Op says there's a snapped drill bit in the middle on the hex.

@DC29 how much depth do you have in the hex before you hit the drill bit?

I'd imagine that the axle will be hollow so hammering a tor bit into the other (open) end and unwinding it that way might be the way to go.

Can we have a pic of the dropout on the other side so we can see the other end of the axle?