Mudguard screws sheared off and embedded in frame

[ms10]

Hi,

I fitted mudguards to my titanium road bike a few months ago. However, this morning, after a cold night in the shed, both screws which attach the rear mudguard's stays to the bike's seat stay sheared clean off. I now have the remains of the two screws embedded in the frame's screw holes. They are completely flush - so nothing to grab hold of with pliers.

The exposed surface of the embedded screws is also slightly convex and uneven, making it impossible to drill a screw extractor tool bit into them. I have tried, but the bit just slides off into the frame - thus potentially making the situation worse.

Any suggestions how to get them out?

Thanks
Mark

[Brucey]

before drilling you should centre-punch the place where you want to drill, and if necessary start the hole at an angle with a pilot drill so that subsequent drills remain centred.

Other things that may help are

- axial percussion
- left-handed drill bits
- heat

It is pretty much imperative that you use anti-seize on screws which are threaded into Ti bosses; seizure is very commonplace otherwise.

cheers

[ms10]

Thanks.

By the way, has anyone had any luck using a metal-compatible glue, such as epoxy resin? I'm wondering if a small dab connecting the end of the screw to a screwdriver would be strong enough to allow the screw's removal.

[Jdsk]

I wouldn't even try.

Brucey has described how to do it. (In other settings I might add cutting a slot for a screwdriver and welding a nut or lever on the stub.)

Jonathan

[fastpedaller]

If both ends of the remaining screw piece are accessible, you could try using a pair of old pincers ground down to a 4mm diameter on each of the ends, so that you can grip the part without damaging the frame, and rotate the part gradually again and again until you free it.

[Mick F]

Do the screws fit on the dropouts?
Can you see the other end of the screws?

Any chance of a photo?

[ms10]

Do the screws fit on the dropouts?
Can you see the other end of the screws?

Any chance of a photo?

Attached.

I've ordered a centre punch tool for metal. Should be with me tomorrow. Guess i'll have to fully charge the drill and see if i can put a small hole in the middle of each. If I can then the reverse-threaded screw remover should do the rest.

I've also read that a little WD40 should help in easing their removal.

[Jdsk]

I've also read that a little WD40 should help in easing their removal.

Give it a long soak with penetrating fluid, not ordinary WD-40.

Jonathan

[Mick F]

Any chance of a photo?

Attached.

Oh dear!

Yes, drill a small hole as centrally as you can.

[julianm]

Might be an idea to get that `burn your fingers` hot with a hairdryer an inch away before you try remove it. Good luck!

[iandusud]

A couple of thoughts. Although the damaged screw is flush with the boss, the boss is proud of the frame so you could cut a slot in the boss and the screw allowing you to get a screwdriver on the screw. However I imagine that the screw is well and truly corroded in the boss so before attempting to move it with a screwdriver you should, as previously suggested, soak it in penetrating fluid and apply heat if it doesn't move before damaging the slot. Another thought is if you have access to a mig welder you might be able to carefully build up some weld with a thin wire on the end of the screw to give you something to hold with pliers. This would have the added benefit of heating the screw and boss.

[531colin]

M5 bolts are pretty small to get a stud remover into; I would first try left hand drill bits....exactly what it says....they drill counter-clockwise, and as they "bite" they tend to back the bolt out. If they don't back the bolt out, there is nothing lost, you can still try stud extractor.

[SimonCelsa]

I've ordered a centre punch tool for metal

Make sure you put a dummy axle between the dropouts before clouting the centre punch with the lump hammer!!

[Valbrona]

probably a lost cause.

Don't jigger your frame up - work with extreme caution.

Clip on mudguards are an option.

[mattsccm]

That will drill with left hand drill. Centre punch first. At the very worst you keep going up a drill size until whats left is thin enough to pick out. Fiddly but easy enough.