One shot left. Rounded disc brake mount screw

[Shrike]

Bigger of a time dealing with these screws, reckon guy who did the install overtorqued them.

Last one to come off moved a touch then the hex slipped. That one slip was enough to ruin any chance of another proper shot.

Sawed across the bolt but again the screw chipped a little under force so now you can’t get any purchase on it with the flathead.

Just sawed another channel into it again. Last shot.

Any tips?

Currently it’s not wide enough to take the flathead anyway. Thinking it over first.

[RECAR77]

last resort is flexing the head completely off. once the tension is gone (and the threads aren't damaged) it should be able to unscrew relatively easily by gripping the rest of the threads with pliers

[dudemanppl]

If you have the other bolt off, try and rotate the whole assembly counterclockwise if possible. That should loosen the bolt enough hopefully.

[R0CKETMAN]

Ez out with a bit of heat

[tinozee]

Have you tried an extractor bit? Usually the hack saw to make a deep groove for a flat head works.

[Shrike]

Tension is gone now... you can move the mount side to side under it, just about. Still an absolute bugger.

Does that mean if the head is taken off, it won't be removable with pliers and the fork is written off?


Didn't use an extractor bit.. screwdriver couldn't get enough torque, so had to buy this weird thing which worked for a tiny turn until the bowl chipped again: https://www.amazon.co.uk/Facom-AGT-ISOR ... 809&sr=8-2

[Nickldn]

Would second the suggestion to use an extraction bit.

It's gentle compared to banging and heating. You want to keep your fork intact after all.

[Maddie]

Definitely bolt extractor. Get a high quality one since you are running out of options quickly.
A bit of heat can be helpful in case loctite was used. But be careful, paint doesn't like heat a lot.

[RECAR77]

Tension is gone now... you can move the mount side to side under it, just about. Still an absolute bugger.

Does that mean if the head is taken off, it won't be removable with pliers and the fork is written off?

if the brake adapter moves without much force then I assume the thread is galled. since I assume the insert in the fork is alu and the bolt is steel, the fork might be destroyed no matter if you remove the bolt or not. but there is no way of telling until you manage to remove the bolt. definitely try a screw extractor before removing the head.

[Shrike]

Yeah looks like
Loctite comes on these SRAM bolts. Other screws were a bugger too, and I think the Loctite is partly the blame. The blue stuff though, not supposed to be that strong. I use it myself on other parts and it’s fine.

Checking out this easy out thing. Never heard of it before today. You guys would give the flat head one more shot (after widening it) then if not use the bolt extractor thing? Guess a I’ll need one that’s super small..

[TobinHatesYou]

if the brake adapter moves without much force then I assume the thread is galled. since I assume the insert in the fork is alu and the bolt is steel, the fork might be destroyed no matter if you remove the bolt or not. but there is no way of telling until you manage to remove the bolt. definitely try a screw extractor before removing the head.

I doubt it’s galled. What’s more likely is someone cross-threaded the bolt and kept on going.

[DanielNorway]

One option is to file both sides of the head and use a small adjustable wrench, worked for me on similar screw.

[Shrike]

Daniel that’s really clever! Will try the second channel with a flathead tomorrow ( need find a way to widen it just a touch) and then if that fails I’ll make it wrenchable!

Bought replacement bolts too, SRAM ones. Remove the loctite they come with from them?

[bikeboy1tr]

Get yourself a lefthand drillbit of the proper diameter along with the extractor bit. You will have to drill a hole to install the extractor bit anyway but with the lefthand drillbit you might just get it to come out if the threads are not to damaged. As you drill into it and if lucky the lefthand bit will pick up and the bolt will back right out. If not then your drilling a hole to place the extractor into anyway so no loss there. Try to get that bit centered on the head as best you can typically with a smaller drillbit after you have centerpunched it.
Good luck.

[ghisallo2003]

I have an excellent team mate to whom I always send such parts. Even though he has moved away, I send him parts that have been brought to me. As well as the solutions you have highlighted, his solutions include spot welding a hex bolt into place for larger seized parts, and ultimately to drilling out the centre of the offending bolt at which point threads often fall away, and then retapping.