Stuck allen brake nut in carbon fork

I have the above issue on a frame I just bought, the nut is also completely rounded so a 5mm allen key just spins in it. I've removed the fork and tried screwing a headset bolt in from the front and tapping it but a bit apprehensive about doing this too hard. I can't really think of any other solution except drilling it out which seems a bit drastic and risky.

Any suggestions?

A Torx key can purchase where an Allen key can't.

Or hit the bolt harder.

Maybe a 6mm Allen key tapped into the rounded 5mm head. Or try to drill it out. If you were really worried a good engineer could do it for a small fee obviously.

Thanks for both the above. As there's no brake on the front of it I wouldn't be able to loosen it off against anything, however if I can get it to turn that might free it up enough to then tap out, or I suppose I just spin a brake calliper onto it. Only concern is that tapping in a torx/6mm bit might drive it even further into where it's currently stuck.

Will give some attention this evening and see how it goes, would rather avoid paying an engineer.

Penetrating lube of some kind? Carbon friendly bike oil even? Just something to help it along between taps

A Torx key won't need to be forced in.

If you are afraid of damaging the fork then I'd return it to the seller.

Otherwise bash it harder from the other side.

Sounds like a long shot but try Coca Cola. It's an anti corrosive and penetrates really well. I use it at work for removing siezed glow plugs in engines.

Or dremel the shit out of it.

Can you post a photo of the issue.

Screw and bolt extractor?

Spot-weld allen key or steel rod (pre-bent) to screw.

Put an M6 bolt in it from the front and batter the fuck out of it. Worst that'll happen is that it'll take some paint/laquer with it*.

*Probably.

I say we take off and nuke the entire bike from orbit.

It's the only way to be sure.

long enough M6 bolt through the front is best option

^ Longer M6 bolt, or a punch and hammer if you have one, screwdriver and hammer if you don't.

Insert M6 bolt from the front. Now turn the whole thing over, placing on a hard surface (eg workbench) so that the M6 bolt is resting on the workbench.

Now tap in a Torx wrench bit (gently). Because you have the M6 bolt on the other side, this won't drive the bolt any further into the fork.

Once the Torx bit is in place, unscrew gently whilst pushing the fork gently downwards, so that your M6 bolt helps push the nut out.

Perfect!

Two years between posts is a long time, but it was worth the wait :)

This ^^ is what I'm going to try, thanks.

failing that might get a bit more involved with the hammer, to be honest it was a bit of a token effort first time round, just feels a bit dodgy whacking carbon stuff.

Out of interest how does coke measure up against plus gas? (what I used before)

Is it a full carbon fork, or just the legs...

A proper anti-seize solution will trounce a home-brew effort (the latter being more dilute than the former).

Top of the offending nut just visible

Dustpan & brush at the ready.

Well we use Coke for siezed in glow plugs on Diesel engines because wd40 doesn't work. It's to do with the chemicals in Coke. Pretty bad really considering we all drink it.

I'm more of a Pepsi drinker tbh